FFmpeg/libavcodec/vc1dec.c

/*
 * VC-1 and WMV3 decoder
 * Copyright (c) 2011 Mashiat Sarker Shakkhar
 * Copyright (c) 2006-2007 Konstantin Shishkov
 * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * VC-1 and WMV3 decoder
 */

#include "internal.h"
#include "avcodec.h"
#include "error_resilience.h"
#include "mpegvideo.h"
#include "h263.h"
#include "h264chroma.h"
#include "vc1.h"
#include "vc1data.h"
#include "vc1acdata.h"
#include "msmpeg4data.h"
#include "unary.h"
#include "mathops.h"
#include "vdpau_internal.h"
#include "libavutil/avassert.h"

#undef NDEBUG
#include <assert.h>

#define MB_INTRA_VLC_BITS 9
#define DC_VLC_BITS 9


// offset tables for interlaced picture MVDATA decoding
static const int offset_table1[9] = {  0,  1,  2,  4,  8, 16, 32,  64, 128 };
static const int offset_table2[9] = {  0,  1,  3,  7, 15, 31, 63, 127, 255 };

/***********************************************************************/
/**
 * @name VC-1 Bitplane decoding
 * @see 8.7, p56
 * @{
 */

/**
 * Imode types
 * @{
 */
enum Imode {
    IMODE_RAW,
    IMODE_NORM2,
    IMODE_DIFF2,
    IMODE_NORM6,
    IMODE_DIFF6,
    IMODE_ROWSKIP,
    IMODE_COLSKIP
};
/** @} */ //imode defines

static void init_block_index(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    ff_init_block_index(s);
    if (v->field_mode && !(v->second_field ^ v->tff)) {
        s->dest[0] += s->current_picture_ptr->f.linesize[0];
        s->dest[1] += s->current_picture_ptr->f.linesize[1];
        s->dest[2] += s->current_picture_ptr->f.linesize[2];
    }
}

/** @} */ //Bitplane group

static void vc1_put_signed_blocks_clamped(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int topleft_mb_pos, top_mb_pos;
    int stride_y, fieldtx = 0;
    int v_dist;

    /* The put pixels loop is always one MB row behind the decoding loop,
     * because we can only put pixels when overlap filtering is done, and
     * for filtering of the bottom edge of a MB, we need the next MB row
     * present as well.
     * Within the row, the put pixels loop is also one MB col behind the
     * decoding loop. The reason for this is again, because for filtering
     * of the right MB edge, we need the next MB present. */
    if (!s->first_slice_line) {
        if (s->mb_x) {
            topleft_mb_pos = (s->mb_y - 1) * s->mb_stride + s->mb_x - 1;
            if (v->fcm == ILACE_FRAME)
                fieldtx = v->fieldtx_plane[topleft_mb_pos];
            stride_y       = s->linesize << fieldtx;
            v_dist         = (16 - fieldtx) >> (fieldtx == 0);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][0],
                                             s->dest[0] - 16 * s->linesize - 16,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][1],
                                             s->dest[0] - 16 * s->linesize - 8,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][2],
                                             s->dest[0] - v_dist * s->linesize - 16,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][3],
                                             s->dest[0] - v_dist * s->linesize - 8,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][4],
                                             s->dest[1] - 8 * s->uvlinesize - 8,
                                             s->uvlinesize);
            s->dsp.put_signed_pixels_clamped(v->block[v->topleft_blk_idx][5],
                                             s->dest[2] - 8 * s->uvlinesize - 8,
                                             s->uvlinesize);
        }
        if (s->mb_x == s->mb_width - 1) {
            top_mb_pos = (s->mb_y - 1) * s->mb_stride + s->mb_x;
            if (v->fcm == ILACE_FRAME)
                fieldtx = v->fieldtx_plane[top_mb_pos];
            stride_y   = s->linesize << fieldtx;
            v_dist     = fieldtx ? 15 : 8;
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][0],
                                             s->dest[0] - 16 * s->linesize,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][1],
                                             s->dest[0] - 16 * s->linesize + 8,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][2],
                                             s->dest[0] - v_dist * s->linesize,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][3],
                                             s->dest[0] - v_dist * s->linesize + 8,
                                             stride_y);
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][4],
                                             s->dest[1] - 8 * s->uvlinesize,
                                             s->uvlinesize);
            s->dsp.put_signed_pixels_clamped(v->block[v->top_blk_idx][5],
                                             s->dest[2] - 8 * s->uvlinesize,
                                             s->uvlinesize);
        }
    }

#define inc_blk_idx(idx) do { \
        idx++; \
        if (idx >= v->n_allocated_blks) \
            idx = 0; \
    } while (0)

    inc_blk_idx(v->topleft_blk_idx);
    inc_blk_idx(v->top_blk_idx);
    inc_blk_idx(v->left_blk_idx);
    inc_blk_idx(v->cur_blk_idx);
}

static void vc1_loop_filter_iblk(VC1Context *v, int pq)
{
    MpegEncContext *s = &v->s;
    int j;
    if (!s->first_slice_line) {
        v->vc1dsp.vc1_v_loop_filter16(s->dest[0], s->linesize, pq);
        if (s->mb_x)
            v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize, s->linesize, pq);
        v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize + 8, s->linesize, pq);
        for (j = 0; j < 2; j++) {
            v->vc1dsp.vc1_v_loop_filter8(s->dest[j + 1], s->uvlinesize, pq);
            if (s->mb_x)
                v->vc1dsp.vc1_h_loop_filter8(s->dest[j + 1] - 8 * s->uvlinesize, s->uvlinesize, pq);
        }
    }
    v->vc1dsp.vc1_v_loop_filter16(s->dest[0] + 8 * s->linesize, s->linesize, pq);

    if (s->mb_y == s->end_mb_y - 1) {
        if (s->mb_x) {
            v->vc1dsp.vc1_h_loop_filter16(s->dest[0], s->linesize, pq);
            v->vc1dsp.vc1_h_loop_filter8(s->dest[1], s->uvlinesize, pq);
            v->vc1dsp.vc1_h_loop_filter8(s->dest[2], s->uvlinesize, pq);
        }
        v->vc1dsp.vc1_h_loop_filter16(s->dest[0] + 8, s->linesize, pq);
    }
}

static void vc1_loop_filter_iblk_delayed(VC1Context *v, int pq)
{
    MpegEncContext *s = &v->s;
    int j;

    /* The loopfilter runs 1 row and 1 column behind the overlap filter, which
     * means it runs two rows/cols behind the decoding loop. */
    if (!s->first_slice_line) {
        if (s->mb_x) {
            if (s->mb_y >= s->start_mb_y + 2) {
                v->vc1dsp.vc1_v_loop_filter16(s->dest[0] - 16 * s->linesize - 16, s->linesize, pq);

                if (s->mb_x >= 2)
                    v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 32 * s->linesize - 16, s->linesize, pq);
                v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 32 * s->linesize - 8, s->linesize, pq);
                for (j = 0; j < 2; j++) {
                    v->vc1dsp.vc1_v_loop_filter8(s->dest[j + 1] - 8 * s->uvlinesize - 8, s->uvlinesize, pq);
                    if (s->mb_x >= 2) {
                        v->vc1dsp.vc1_h_loop_filter8(s->dest[j + 1] - 16 * s->uvlinesize - 8, s->uvlinesize, pq);
                    }
                }
            }
            v->vc1dsp.vc1_v_loop_filter16(s->dest[0] - 8 * s->linesize - 16, s->linesize, pq);
        }

        if (s->mb_x == s->mb_width - 1) {
            if (s->mb_y >= s->start_mb_y + 2) {
                v->vc1dsp.vc1_v_loop_filter16(s->dest[0] - 16 * s->linesize, s->linesize, pq);

                if (s->mb_x)
                    v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 32 * s->linesize, s->linesize, pq);
                v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 32 * s->linesize + 8, s->linesize, pq);
                for (j = 0; j < 2; j++) {
                    v->vc1dsp.vc1_v_loop_filter8(s->dest[j + 1] - 8 * s->uvlinesize, s->uvlinesize, pq);
                    if (s->mb_x >= 2) {
                        v->vc1dsp.vc1_h_loop_filter8(s->dest[j + 1] - 16 * s->uvlinesize, s->uvlinesize, pq);
                    }
                }
            }
            v->vc1dsp.vc1_v_loop_filter16(s->dest[0] - 8 * s->linesize, s->linesize, pq);
        }

        if (s->mb_y == s->end_mb_y) {
            if (s->mb_x) {
                if (s->mb_x >= 2)
                    v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize - 16, s->linesize, pq);
                v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize - 8, s->linesize, pq);
                if (s->mb_x >= 2) {
                    for (j = 0; j < 2; j++) {
                        v->vc1dsp.vc1_h_loop_filter8(s->dest[j + 1] - 8 * s->uvlinesize - 8, s->uvlinesize, pq);
                    }
                }
            }

            if (s->mb_x == s->mb_width - 1) {
                if (s->mb_x)
                    v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize, s->linesize, pq);
                v->vc1dsp.vc1_h_loop_filter16(s->dest[0] - 16 * s->linesize + 8, s->linesize, pq);
                if (s->mb_x) {
                    for (j = 0; j < 2; j++) {
                        v->vc1dsp.vc1_h_loop_filter8(s->dest[j + 1] - 8 * s->uvlinesize, s->uvlinesize, pq);
                    }
                }
            }
        }
    }
}

static void vc1_smooth_overlap_filter_iblk(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int mb_pos;

    if (v->condover == CONDOVER_NONE)
        return;

    mb_pos = s->mb_x + s->mb_y * s->mb_stride;

    /* Within a MB, the horizontal overlap always runs before the vertical.
     * To accomplish that, we run the H on left and internal borders of the
     * currently decoded MB. Then, we wait for the next overlap iteration
     * to do H overlap on the right edge of this MB, before moving over and
     * running the V overlap. Therefore, the V overlap makes us trail by one
     * MB col and the H overlap filter makes us trail by one MB row. This
     * is reflected in the time at which we run the put_pixels loop. */
    if (v->condover == CONDOVER_ALL || v->pq >= 9 || v->over_flags_plane[mb_pos]) {
        if (s->mb_x && (v->condover == CONDOVER_ALL || v->pq >= 9 ||
                        v->over_flags_plane[mb_pos - 1])) {
            v->vc1dsp.vc1_h_s_overlap(v->block[v->left_blk_idx][1],
                                      v->block[v->cur_blk_idx][0]);
            v->vc1dsp.vc1_h_s_overlap(v->block[v->left_blk_idx][3],
                                      v->block[v->cur_blk_idx][2]);
            if (!(s->flags & CODEC_FLAG_GRAY)) {
                v->vc1dsp.vc1_h_s_overlap(v->block[v->left_blk_idx][4],
                                          v->block[v->cur_blk_idx][4]);
                v->vc1dsp.vc1_h_s_overlap(v->block[v->left_blk_idx][5],
                                          v->block[v->cur_blk_idx][5]);
            }
        }
        v->vc1dsp.vc1_h_s_overlap(v->block[v->cur_blk_idx][0],
                                  v->block[v->cur_blk_idx][1]);
        v->vc1dsp.vc1_h_s_overlap(v->block[v->cur_blk_idx][2],
                                  v->block[v->cur_blk_idx][3]);

        if (s->mb_x == s->mb_width - 1) {
            if (!s->first_slice_line && (v->condover == CONDOVER_ALL || v->pq >= 9 ||
                                         v->over_flags_plane[mb_pos - s->mb_stride])) {
                v->vc1dsp.vc1_v_s_overlap(v->block[v->top_blk_idx][2],
                                          v->block[v->cur_blk_idx][0]);
                v->vc1dsp.vc1_v_s_overlap(v->block[v->top_blk_idx][3],
                                          v->block[v->cur_blk_idx][1]);
                if (!(s->flags & CODEC_FLAG_GRAY)) {
                    v->vc1dsp.vc1_v_s_overlap(v->block[v->top_blk_idx][4],
                                              v->block[v->cur_blk_idx][4]);
                    v->vc1dsp.vc1_v_s_overlap(v->block[v->top_blk_idx][5],
                                              v->block[v->cur_blk_idx][5]);
                }
            }
            v->vc1dsp.vc1_v_s_overlap(v->block[v->cur_blk_idx][0],
                                      v->block[v->cur_blk_idx][2]);
            v->vc1dsp.vc1_v_s_overlap(v->block[v->cur_blk_idx][1],
                                      v->block[v->cur_blk_idx][3]);
        }
    }
    if (s->mb_x && (v->condover == CONDOVER_ALL || v->over_flags_plane[mb_pos - 1])) {
        if (!s->first_slice_line && (v->condover == CONDOVER_ALL || v->pq >= 9 ||
                                     v->over_flags_plane[mb_pos - s->mb_stride - 1])) {
            v->vc1dsp.vc1_v_s_overlap(v->block[v->topleft_blk_idx][2],
                                      v->block[v->left_blk_idx][0]);
            v->vc1dsp.vc1_v_s_overlap(v->block[v->topleft_blk_idx][3],
                                      v->block[v->left_blk_idx][1]);
            if (!(s->flags & CODEC_FLAG_GRAY)) {
                v->vc1dsp.vc1_v_s_overlap(v->block[v->topleft_blk_idx][4],
                                          v->block[v->left_blk_idx][4]);
                v->vc1dsp.vc1_v_s_overlap(v->block[v->topleft_blk_idx][5],
                                          v->block[v->left_blk_idx][5]);
            }
        }
        v->vc1dsp.vc1_v_s_overlap(v->block[v->left_blk_idx][0],
                                  v->block[v->left_blk_idx][2]);
        v->vc1dsp.vc1_v_s_overlap(v->block[v->left_blk_idx][1],
                                  v->block[v->left_blk_idx][3]);
    }
}

/** Do motion compensation over 1 macroblock
 * Mostly adapted hpel_motion and qpel_motion from mpegvideo.c
 */
static void vc1_mc_1mv(VC1Context *v, int dir)
{
    MpegEncContext *s = &v->s;
    H264ChromaContext *h264chroma = &v->h264chroma;
    uint8_t *srcY, *srcU, *srcV;
    int dxy, mx, my, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y;
    int v_edge_pos = s->v_edge_pos >> v->field_mode;
    int i;
    uint8_t (*luty)[256], (*lutuv)[256];
    int use_ic;

    if ((!v->field_mode ||
         (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) &&
        !v->s.last_picture.f.data[0])
        return;

    mx = s->mv[dir][0][0];
    my = s->mv[dir][0][1];

    // store motion vectors for further use in B frames
    if (s->pict_type == AV_PICTURE_TYPE_P) {
        for (i = 0; i < 4; i++) {
            s->current_picture.motion_val[1][s->block_index[i] + v->blocks_off][0] = mx;
            s->current_picture.motion_val[1][s->block_index[i] + v->blocks_off][1] = my;
        }
    }

    uvmx = (mx + ((mx & 3) == 3)) >> 1;
    uvmy = (my + ((my & 3) == 3)) >> 1;
    v->luma_mv[s->mb_x][0] = uvmx;
    v->luma_mv[s->mb_x][1] = uvmy;

    if (v->field_mode &&
        v->cur_field_type != v->ref_field_type[dir]) {
        my   = my   - 2 + 4 * v->cur_field_type;
        uvmy = uvmy - 2 + 4 * v->cur_field_type;
    }

    // fastuvmc shall be ignored for interlaced frame picture
    if (v->fastuvmc && (v->fcm != ILACE_FRAME)) {
        uvmx = uvmx + ((uvmx < 0) ? (uvmx & 1) : -(uvmx & 1));
        uvmy = uvmy + ((uvmy < 0) ? (uvmy & 1) : -(uvmy & 1));
    }
    if (!dir) {
        if (v->field_mode && (v->cur_field_type != v->ref_field_type[dir]) && v->second_field) {
            srcY = s->current_picture.f.data[0];
            srcU = s->current_picture.f.data[1];
            srcV = s->current_picture.f.data[2];
            luty  = v->curr_luty;
            lutuv = v->curr_lutuv;
            use_ic = v->curr_use_ic;
        } else {
            srcY = s->last_picture.f.data[0];
            srcU = s->last_picture.f.data[1];
            srcV = s->last_picture.f.data[2];
            luty  = v->last_luty;
            lutuv = v->last_lutuv;
            use_ic = v->last_use_ic;
        }
    } else {
        srcY = s->next_picture.f.data[0];
        srcU = s->next_picture.f.data[1];
        srcV = s->next_picture.f.data[2];
        luty  = v->next_luty;
        lutuv = v->next_lutuv;
        use_ic = v->next_use_ic;
    }

    if (!srcY || !srcU) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
        return;
    }

    src_x   = s->mb_x * 16 + (mx   >> 2);
    src_y   = s->mb_y * 16 + (my   >> 2);
    uvsrc_x = s->mb_x *  8 + (uvmx >> 2);
    uvsrc_y = s->mb_y *  8 + (uvmy >> 2);

    if (v->profile != PROFILE_ADVANCED) {
        src_x   = av_clip(  src_x, -16, s->mb_width  * 16);
        src_y   = av_clip(  src_y, -16, s->mb_height * 16);
        uvsrc_x = av_clip(uvsrc_x,  -8, s->mb_width  *  8);
        uvsrc_y = av_clip(uvsrc_y,  -8, s->mb_height *  8);
    } else {
        src_x   = av_clip(  src_x, -17, s->avctx->coded_width);
        src_y   = av_clip(  src_y, -18, s->avctx->coded_height + 1);
        uvsrc_x = av_clip(uvsrc_x,  -8, s->avctx->coded_width  >> 1);
        uvsrc_y = av_clip(uvsrc_y,  -8, s->avctx->coded_height >> 1);
    }

    srcY += src_y   * s->linesize   + src_x;
    srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
    srcV += uvsrc_y * s->uvlinesize + uvsrc_x;

    if (v->field_mode && v->ref_field_type[dir]) {
        srcY += s->current_picture_ptr->f.linesize[0];
        srcU += s->current_picture_ptr->f.linesize[1];
        srcV += s->current_picture_ptr->f.linesize[2];
    }

    /* for grayscale we should not try to read from unknown area */
    if (s->flags & CODEC_FLAG_GRAY) {
        srcU = s->edge_emu_buffer + 18 * s->linesize;
        srcV = s->edge_emu_buffer + 18 * s->linesize;
    }

    if (v->rangeredfrm || use_ic
        || s->h_edge_pos < 22 || v_edge_pos < 22
        || (unsigned)(src_x - s->mspel) > s->h_edge_pos - (mx&3) - 16 - s->mspel * 3
        || (unsigned)(src_y - 1)        > v_edge_pos    - (my&3) - 16 - 3) {
        uint8_t *uvbuf = s->edge_emu_buffer + 19 * s->linesize;

        srcY -= s->mspel * (1 + s->linesize);
        s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->linesize,
                                 srcY, s->linesize,
                                 17 + s->mspel * 2, 17 + s->mspel * 2,
                                 src_x - s->mspel, src_y - s->mspel,
                                 s->h_edge_pos, v_edge_pos);
        srcY = s->edge_emu_buffer;
        s->vdsp.emulated_edge_mc(uvbuf, s->uvlinesize, srcU, s->uvlinesize,
                                 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        s->vdsp.emulated_edge_mc(uvbuf + 16, s->uvlinesize, srcV, s->uvlinesize,
                                 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        srcU = uvbuf;
        srcV = uvbuf + 16;
        /* if we deal with range reduction we need to scale source blocks */
        if (v->rangeredfrm) {
            int i, j;
            uint8_t *src, *src2;

            src = srcY;
            for (j = 0; j < 17 + s->mspel * 2; j++) {
                for (i = 0; i < 17 + s->mspel * 2; i++)
                    src[i] = ((src[i] - 128) >> 1) + 128;
                src += s->linesize;
            }
            src  = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                for (i = 0; i < 9; i++) {
                    src[i]  = ((src[i]  - 128) >> 1) + 128;
                    src2[i] = ((src2[i] - 128) >> 1) + 128;
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }
        /* if we deal with intensity compensation we need to scale source blocks */
        if (use_ic) {
            int i, j;
            uint8_t *src, *src2;

            src = srcY;
            for (j = 0; j < 17 + s->mspel * 2; j++) {
                int f = v->field_mode ? v->ref_field_type[dir] : ((j + src_y - s->mspel) & 1) ;
                for (i = 0; i < 17 + s->mspel * 2; i++)
                    src[i] = luty[f][src[i]];
                src += s->linesize;
            }
            src  = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                int f = v->field_mode ? v->ref_field_type[dir] : ((j + uvsrc_y) & 1);
                for (i = 0; i < 9; i++) {
                    src[i]  = lutuv[f][src[i]];
                    src2[i] = lutuv[f][src2[i]];
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }
        srcY += s->mspel * (1 + s->linesize);
    }

    if (s->mspel) {
        dxy = ((my & 3) << 2) | (mx & 3);
        v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0]    , srcY    , s->linesize, v->rnd);
        v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8, srcY + 8, s->linesize, v->rnd);
        srcY += s->linesize * 8;
        v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8 * s->linesize    , srcY    , s->linesize, v->rnd);
        v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8 * s->linesize + 8, srcY + 8, s->linesize, v->rnd);
    } else { // hpel mc - always used for luma
        dxy = (my & 2) | ((mx & 2) >> 1);
        if (!v->rnd)
            s->hdsp.put_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);
        else
            s->hdsp.put_no_rnd_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);
    }

    if (s->flags & CODEC_FLAG_GRAY) return;
    /* Chroma MC always uses qpel bilinear */
    uvmx = (uvmx & 3) << 1;
    uvmy = (uvmy & 3) << 1;
    if (!v->rnd) {
        h264chroma->put_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
        h264chroma->put_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
    } else {
        v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
        v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
    }
}

static inline int median4(int a, int b, int c, int d)
{
    if (a < b) {
        if (c < d) return (FFMIN(b, d) + FFMAX(a, c)) / 2;
        else       return (FFMIN(b, c) + FFMAX(a, d)) / 2;
    } else {
        if (c < d) return (FFMIN(a, d) + FFMAX(b, c)) / 2;
        else       return (FFMIN(a, c) + FFMAX(b, d)) / 2;
    }
}

/** Do motion compensation for 4-MV macroblock - luminance block
 */
static void vc1_mc_4mv_luma(VC1Context *v, int n, int dir, int avg)
{
    MpegEncContext *s = &v->s;
    uint8_t *srcY;
    int dxy, mx, my, src_x, src_y;
    int off;
    int fieldmv = (v->fcm == ILACE_FRAME) ? v->blk_mv_type[s->block_index[n]] : 0;
    int v_edge_pos = s->v_edge_pos >> v->field_mode;
    uint8_t (*luty)[256];
    int use_ic;

    if ((!v->field_mode ||
         (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) &&
        !v->s.last_picture.f.data[0])
        return;

    mx = s->mv[dir][n][0];
    my = s->mv[dir][n][1];

    if (!dir) {
        if (v->field_mode && (v->cur_field_type != v->ref_field_type[dir]) && v->second_field) {
            srcY = s->current_picture.f.data[0];
            luty = v->curr_luty;
            use_ic = v->curr_use_ic;
        } else {
            srcY = s->last_picture.f.data[0];
            luty = v->last_luty;
            use_ic = v->last_use_ic;
        }
    } else {
        srcY = s->next_picture.f.data[0];
        luty = v->next_luty;
        use_ic = v->next_use_ic;
    }

    if (!srcY) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
        return;
    }

    if (v->field_mode) {
        if (v->cur_field_type != v->ref_field_type[dir])
            my = my - 2 + 4 * v->cur_field_type;
    }

    if (s->pict_type == AV_PICTURE_TYPE_P && n == 3 && v->field_mode) {
        int same_count = 0, opp_count = 0, k;
        int chosen_mv[2][4][2], f;
        int tx, ty;
        for (k = 0; k < 4; k++) {
            f = v->mv_f[0][s->block_index[k] + v->blocks_off];
            chosen_mv[f][f ? opp_count : same_count][0] = s->mv[0][k][0];
            chosen_mv[f][f ? opp_count : same_count][1] = s->mv[0][k][1];
            opp_count  += f;
            same_count += 1 - f;
        }
        f = opp_count > same_count;
        switch (f ? opp_count : same_count) {
        case 4:
            tx = median4(chosen_mv[f][0][0], chosen_mv[f][1][0],
                         chosen_mv[f][2][0], chosen_mv[f][3][0]);
            ty = median4(chosen_mv[f][0][1], chosen_mv[f][1][1],
                         chosen_mv[f][2][1], chosen_mv[f][3][1]);
            break;
        case 3:
            tx = mid_pred(chosen_mv[f][0][0], chosen_mv[f][1][0], chosen_mv[f][2][0]);
            ty = mid_pred(chosen_mv[f][0][1], chosen_mv[f][1][1], chosen_mv[f][2][1]);
            break;
        case 2:
            tx = (chosen_mv[f][0][0] + chosen_mv[f][1][0]) / 2;
            ty = (chosen_mv[f][0][1] + chosen_mv[f][1][1]) / 2;
            break;
        default:
            av_assert0(0);
        }
        s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = tx;
        s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = ty;
        for (k = 0; k < 4; k++)
            v->mv_f[1][s->block_index[k] + v->blocks_off] = f;
    }

    if (v->fcm == ILACE_FRAME) {  // not sure if needed for other types of picture
        int qx, qy;
        int width  = s->avctx->coded_width;
        int height = s->avctx->coded_height >> 1;
        if (s->pict_type == AV_PICTURE_TYPE_P) {
            s->current_picture.motion_val[1][s->block_index[n] + v->blocks_off][0] = mx;
            s->current_picture.motion_val[1][s->block_index[n] + v->blocks_off][1] = my;
        }
        qx = (s->mb_x * 16) + (mx >> 2);
        qy = (s->mb_y *  8) + (my >> 3);

        if (qx < -17)
            mx -= 4 * (qx + 17);
        else if (qx > width)
            mx -= 4 * (qx - width);
        if (qy < -18)
            my -= 8 * (qy + 18);
        else if (qy > height + 1)
            my -= 8 * (qy - height - 1);
    }

    if ((v->fcm == ILACE_FRAME) && fieldmv)
        off = ((n > 1) ? s->linesize : 0) + (n & 1) * 8;
    else
        off = s->linesize * 4 * (n & 2) + (n & 1) * 8;

    src_x = s->mb_x * 16 + (n & 1) * 8 + (mx >> 2);
    if (!fieldmv)
        src_y = s->mb_y * 16 + (n & 2) * 4 + (my >> 2);
    else
        src_y = s->mb_y * 16 + ((n > 1) ? 1 : 0) + (my >> 2);

    if (v->profile != PROFILE_ADVANCED) {
        src_x = av_clip(src_x, -16, s->mb_width  * 16);
        src_y = av_clip(src_y, -16, s->mb_height * 16);
    } else {
        src_x = av_clip(src_x, -17, s->avctx->coded_width);
        if (v->fcm == ILACE_FRAME) {
            if (src_y & 1)
                src_y = av_clip(src_y, -17, s->avctx->coded_height + 1);
            else
                src_y = av_clip(src_y, -18, s->avctx->coded_height);
        } else {
            src_y = av_clip(src_y, -18, s->avctx->coded_height + 1);
        }
    }

    srcY += src_y * s->linesize + src_x;
    if (v->field_mode && v->ref_field_type[dir])
        srcY += s->current_picture_ptr->f.linesize[0];

    if (fieldmv && !(src_y & 1))
        v_edge_pos--;
    if (fieldmv && (src_y & 1) && src_y < 4)
        src_y--;
    if (v->rangeredfrm || use_ic
        || s->h_edge_pos < 13 || v_edge_pos < 23
        || (unsigned)(src_x - s->mspel) > s->h_edge_pos - (mx & 3) - 8 - s->mspel * 2
        || (unsigned)(src_y - (s->mspel << fieldmv)) > v_edge_pos - (my & 3) - ((8 + s->mspel * 2) << fieldmv)) {
        srcY -= s->mspel * (1 + (s->linesize << fieldmv));
        /* check emulate edge stride and offset */
        s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->linesize, srcY, s->linesize,
                                 9 + s->mspel * 2, (9 + s->mspel * 2) << fieldmv,
                                 src_x - s->mspel, src_y - (s->mspel << fieldmv),
                                 s->h_edge_pos, v_edge_pos);
        srcY = s->edge_emu_buffer;
        /* if we deal with range reduction we need to scale source blocks */
        if (v->rangeredfrm) {
            int i, j;
            uint8_t *src;

            src = srcY;
            for (j = 0; j < 9 + s->mspel * 2; j++) {
                for (i = 0; i < 9 + s->mspel * 2; i++)
                    src[i] = ((src[i] - 128) >> 1) + 128;
                src += s->linesize << fieldmv;
            }
        }
        /* if we deal with intensity compensation we need to scale source blocks */
        if (use_ic) {
            int i, j;
            uint8_t *src;

            src = srcY;
            for (j = 0; j < 9 + s->mspel * 2; j++) {
                int f = v->field_mode ? v->ref_field_type[dir] : (((j<<fieldmv)+src_y - (s->mspel << fieldmv)) & 1);
                for (i = 0; i < 9 + s->mspel * 2; i++)
                    src[i] = luty[f][src[i]];
                src += s->linesize << fieldmv;
            }
        }
        srcY += s->mspel * (1 + (s->linesize << fieldmv));
    }

    if (s->mspel) {
        dxy = ((my & 3) << 2) | (mx & 3);
        if (avg)
            v->vc1dsp.avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + off, srcY, s->linesize << fieldmv, v->rnd);
        else
            v->vc1dsp.put_vc1_mspel_pixels_tab[dxy](s->dest[0] + off, srcY, s->linesize << fieldmv, v->rnd);
    } else { // hpel mc - always used for luma
        dxy = (my & 2) | ((mx & 2) >> 1);
        if (!v->rnd)
            s->hdsp.put_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize, 8);
        else
            s->hdsp.put_no_rnd_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize, 8);
    }
}

static av_always_inline int get_chroma_mv(int *mvx, int *mvy, int *a, int flag, int *tx, int *ty)
{
    int idx, i;
    static const int count[16] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4};

    idx =  ((a[3] != flag) << 3)
         | ((a[2] != flag) << 2)
         | ((a[1] != flag) << 1)
         |  (a[0] != flag);
    if (!idx) {
        *tx = median4(mvx[0], mvx[1], mvx[2], mvx[3]);
        *ty = median4(mvy[0], mvy[1], mvy[2], mvy[3]);
        return 4;
    } else if (count[idx] == 1) {
        switch (idx) {
        case 0x1:
            *tx = mid_pred(mvx[1], mvx[2], mvx[3]);
            *ty = mid_pred(mvy[1], mvy[2], mvy[3]);
            return 3;
        case 0x2:
            *tx = mid_pred(mvx[0], mvx[2], mvx[3]);
            *ty = mid_pred(mvy[0], mvy[2], mvy[3]);
            return 3;
        case 0x4:
            *tx = mid_pred(mvx[0], mvx[1], mvx[3]);
            *ty = mid_pred(mvy[0], mvy[1], mvy[3]);
            return 3;
        case 0x8:
            *tx = mid_pred(mvx[0], mvx[1], mvx[2]);
            *ty = mid_pred(mvy[0], mvy[1], mvy[2]);
            return 3;
        }
    } else if (count[idx] == 2) {
        int t1 = 0, t2 = 0;
        for (i = 0; i < 3; i++)
            if (!a[i]) {
                t1 = i;
                break;
            }
        for (i = t1 + 1; i < 4; i++)
            if (!a[i]) {
                t2 = i;
                break;
            }
        *tx = (mvx[t1] + mvx[t2]) / 2;
        *ty = (mvy[t1] + mvy[t2]) / 2;
        return 2;
    } else {
        return 0;
    }
    return -1;
}

/** Do motion compensation for 4-MV macroblock - both chroma blocks
 */
static void vc1_mc_4mv_chroma(VC1Context *v, int dir)
{
    MpegEncContext *s = &v->s;
    H264ChromaContext *h264chroma = &v->h264chroma;
    uint8_t *srcU, *srcV;
    int uvmx, uvmy, uvsrc_x, uvsrc_y;
    int k, tx = 0, ty = 0;
    int mvx[4], mvy[4], intra[4], mv_f[4];
    int valid_count;
    int chroma_ref_type = v->cur_field_type;
    int v_edge_pos = s->v_edge_pos >> v->field_mode;
    uint8_t (*lutuv)[256];
    int use_ic;

    if (!v->field_mode && !v->s.last_picture.f.data[0])
        return;
    if (s->flags & CODEC_FLAG_GRAY)
        return;

    for (k = 0; k < 4; k++) {
        mvx[k] = s->mv[dir][k][0];
        mvy[k] = s->mv[dir][k][1];
        intra[k] = v->mb_type[0][s->block_index[k]];
        if (v->field_mode)
            mv_f[k] = v->mv_f[dir][s->block_index[k] + v->blocks_off];
    }

    /* calculate chroma MV vector from four luma MVs */
    if (!v->field_mode || (v->field_mode && !v->numref)) {
        valid_count = get_chroma_mv(mvx, mvy, intra, 0, &tx, &ty);
        chroma_ref_type = v->reffield;
        if (!valid_count) {
            s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
            s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;
            v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;
            return; //no need to do MC for intra blocks
        }
    } else {
        int dominant = 0;
        if (mv_f[0] + mv_f[1] + mv_f[2] + mv_f[3] > 2)
            dominant = 1;
        valid_count = get_chroma_mv(mvx, mvy, mv_f, dominant, &tx, &ty);
        if (dominant)
            chroma_ref_type = !v->cur_field_type;
    }
    if (v->field_mode && chroma_ref_type == 1 && v->cur_field_type == 1 && !v->s.last_picture.f.data[0])
        return;
    s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = tx;
    s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = ty;
    uvmx = (tx + ((tx & 3) == 3)) >> 1;
    uvmy = (ty + ((ty & 3) == 3)) >> 1;

    v->luma_mv[s->mb_x][0] = uvmx;
    v->luma_mv[s->mb_x][1] = uvmy;

    if (v->fastuvmc) {
        uvmx = uvmx + ((uvmx < 0) ? (uvmx & 1) : -(uvmx & 1));
        uvmy = uvmy + ((uvmy < 0) ? (uvmy & 1) : -(uvmy & 1));
    }
    // Field conversion bias
    if (v->cur_field_type != chroma_ref_type)
        uvmy += 2 - 4 * chroma_ref_type;

    uvsrc_x = s->mb_x * 8 + (uvmx >> 2);
    uvsrc_y = s->mb_y * 8 + (uvmy >> 2);

    if (v->profile != PROFILE_ADVANCED) {
        uvsrc_x = av_clip(uvsrc_x, -8, s->mb_width  * 8);
        uvsrc_y = av_clip(uvsrc_y, -8, s->mb_height * 8);
    } else {
        uvsrc_x = av_clip(uvsrc_x, -8, s->avctx->coded_width  >> 1);
        uvsrc_y = av_clip(uvsrc_y, -8, s->avctx->coded_height >> 1);
    }

    if (!dir) {
        if (v->field_mode && (v->cur_field_type != chroma_ref_type) && v->second_field) {
            srcU = s->current_picture.f.data[1];
            srcV = s->current_picture.f.data[2];
            lutuv = v->curr_lutuv;
            use_ic = v->curr_use_ic;
        } else {
            srcU = s->last_picture.f.data[1];
            srcV = s->last_picture.f.data[2];
            lutuv = v->last_lutuv;
            use_ic = v->last_use_ic;
        }
    } else {
        srcU = s->next_picture.f.data[1];
        srcV = s->next_picture.f.data[2];
        lutuv = v->next_lutuv;
        use_ic = v->next_use_ic;
    }

    if (!srcU) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
        return;
    }

    srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
    srcV += uvsrc_y * s->uvlinesize + uvsrc_x;

    if (v->field_mode) {
        if (chroma_ref_type) {
            srcU += s->current_picture_ptr->f.linesize[1];
            srcV += s->current_picture_ptr->f.linesize[2];
        }
    }

    if (v->rangeredfrm || use_ic
        || s->h_edge_pos < 18 || v_edge_pos < 18
        || (unsigned)uvsrc_x > (s->h_edge_pos >> 1) - 9
        || (unsigned)uvsrc_y > (v_edge_pos    >> 1) - 9) {
        s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->uvlinesize, srcU,
                                 s->uvlinesize, 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        s->vdsp.emulated_edge_mc(s->edge_emu_buffer + 16, s->uvlinesize, srcV,
                                 s->uvlinesize, 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        srcU = s->edge_emu_buffer;
        srcV = s->edge_emu_buffer + 16;

        /* if we deal with range reduction we need to scale source blocks */
        if (v->rangeredfrm) {
            int i, j;
            uint8_t *src, *src2;

            src  = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                for (i = 0; i < 9; i++) {
                    src[i]  = ((src[i]  - 128) >> 1) + 128;
                    src2[i] = ((src2[i] - 128) >> 1) + 128;
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }
        /* if we deal with intensity compensation we need to scale source blocks */
        if (use_ic) {
            int i, j;
            uint8_t *src, *src2;

            src  = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                int f = v->field_mode ? chroma_ref_type : ((j + uvsrc_y) & 1);
                for (i = 0; i < 9; i++) {
                    src[i]  = lutuv[f][src[i]];
                    src2[i] = lutuv[f][src2[i]];
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }
    }

    /* Chroma MC always uses qpel bilinear */
    uvmx = (uvmx & 3) << 1;
    uvmy = (uvmy & 3) << 1;
    if (!v->rnd) {
        h264chroma->put_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
        h264chroma->put_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
    } else {
        v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
        v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
    }
}

/** Do motion compensation for 4-MV interlaced frame chroma macroblock (both U and V)
 */
static void vc1_mc_4mv_chroma4(VC1Context *v, int dir, int dir2, int avg)
{
    MpegEncContext *s = &v->s;
    H264ChromaContext *h264chroma = &v->h264chroma;
    uint8_t *srcU, *srcV;
    int uvsrc_x, uvsrc_y;
    int uvmx_field[4], uvmy_field[4];
    int i, off, tx, ty;
    int fieldmv = v->blk_mv_type[s->block_index[0]];
    static const int s_rndtblfield[16] = { 0, 0, 1, 2, 4, 4, 5, 6, 2, 2, 3, 8, 6, 6, 7, 12 };
    int v_dist = fieldmv ? 1 : 4; // vertical offset for lower sub-blocks
    int v_edge_pos = s->v_edge_pos >> 1;
    int use_ic;
    uint8_t (*lutuv)[256];

    if (s->flags & CODEC_FLAG_GRAY)
        return;

    for (i = 0; i < 4; i++) {
        int d = i < 2 ? dir: dir2;
        tx = s->mv[d][i][0];
        uvmx_field[i] = (tx + ((tx & 3) == 3)) >> 1;
        ty = s->mv[d][i][1];
        if (fieldmv)
            uvmy_field[i] = (ty >> 4) * 8 + s_rndtblfield[ty & 0xF];
        else
            uvmy_field[i] = (ty + ((ty & 3) == 3)) >> 1;
    }

    for (i = 0; i < 4; i++) {
        off = (i & 1) * 4 + ((i & 2) ? v_dist * s->uvlinesize : 0);
        uvsrc_x = s->mb_x * 8 +  (i & 1) * 4           + (uvmx_field[i] >> 2);
        uvsrc_y = s->mb_y * 8 + ((i & 2) ? v_dist : 0) + (uvmy_field[i] >> 2);
        // FIXME: implement proper pull-back (see vc1cropmv.c, vc1CROPMV_ChromaPullBack())
        uvsrc_x = av_clip(uvsrc_x, -8, s->avctx->coded_width  >> 1);
        uvsrc_y = av_clip(uvsrc_y, -8, s->avctx->coded_height >> 1);
        if (i < 2 ? dir : dir2) {
            srcU = s->next_picture.f.data[1];
            srcV = s->next_picture.f.data[2];
            lutuv  = v->next_lutuv;
            use_ic = v->next_use_ic;
        } else {
            srcU = s->last_picture.f.data[1];
            srcV = s->last_picture.f.data[2];
            lutuv  = v->last_lutuv;
            use_ic = v->last_use_ic;
        }
        if (!srcU)
            return;
        srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
        srcV += uvsrc_y * s->uvlinesize + uvsrc_x;
        uvmx_field[i] = (uvmx_field[i] & 3) << 1;
        uvmy_field[i] = (uvmy_field[i] & 3) << 1;

        if (fieldmv && !(uvsrc_y & 1))
            v_edge_pos = (s->v_edge_pos >> 1) - 1;

        if (fieldmv && (uvsrc_y & 1) && uvsrc_y < 2)
            uvsrc_y--;
        if (use_ic
            || s->h_edge_pos < 10 || v_edge_pos < (5 << fieldmv)
            || (unsigned)uvsrc_x > (s->h_edge_pos >> 1) - 5
            || (unsigned)uvsrc_y > v_edge_pos - (5 << fieldmv)) {
            s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->uvlinesize, srcU,
                                     s->uvlinesize, 5, (5 << fieldmv), uvsrc_x,
                                     uvsrc_y, s->h_edge_pos >> 1, v_edge_pos);
            s->vdsp.emulated_edge_mc(s->edge_emu_buffer + 16, s->uvlinesize, srcV,
                                     s->uvlinesize, 5, (5 << fieldmv), uvsrc_x,
                                     uvsrc_y, s->h_edge_pos >> 1, v_edge_pos);
            srcU = s->edge_emu_buffer;
            srcV = s->edge_emu_buffer + 16;

            /* if we deal with intensity compensation we need to scale source blocks */
            if (use_ic) {
                int i, j;
                uint8_t *src, *src2;

                src  = srcU;
                src2 = srcV;
                for (j = 0; j < 5; j++) {
                    int f = (uvsrc_y + (j << fieldmv)) & 1;
                    for (i = 0; i < 5; i++) {
                        src[i]  = lutuv[f][src[i]];
                        src2[i] = lutuv[f][src2[i]];
                    }
                    src  += s->uvlinesize << fieldmv;
                    src2 += s->uvlinesize << fieldmv;
                }
            }
        }
        if (avg) {
            if (!v->rnd) {
                h264chroma->avg_h264_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                h264chroma->avg_h264_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
            } else {
                v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
            }
        } else {
            if (!v->rnd) {
                h264chroma->put_h264_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                h264chroma->put_h264_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
            } else {
                v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
            }
        }
    }
}

/***********************************************************************/
/**
 * @name VC-1 Block-level functions
 * @see 7.1.4, p91 and 8.1.1.7, p(1)04
 * @{
 */

/**
 * @def GET_MQUANT
 * @brief Get macroblock-level quantizer scale
 */
#define GET_MQUANT()                                           \
    if (v->dquantfrm) {                                        \
        int edges = 0;                                         \
        if (v->dqprofile == DQPROFILE_ALL_MBS) {               \
            if (v->dqbilevel) {                                \
                mquant = (get_bits1(gb)) ? v->altpq : v->pq;   \
            } else {                                           \
                mqdiff = get_bits(gb, 3);                      \
                if (mqdiff != 7)                               \
                    mquant = v->pq + mqdiff;                   \
                else                                           \
                    mquant = get_bits(gb, 5);                  \
            }                                                  \
        }                                                      \
        if (v->dqprofile == DQPROFILE_SINGLE_EDGE)             \
            edges = 1 << v->dqsbedge;                          \
        else if (v->dqprofile == DQPROFILE_DOUBLE_EDGES)       \
            edges = (3 << v->dqsbedge) % 15;                   \
        else if (v->dqprofile == DQPROFILE_FOUR_EDGES)         \
            edges = 15;                                        \
        if ((edges&1) && !s->mb_x)                             \
            mquant = v->altpq;                                 \
        if ((edges&2) && s->first_slice_line)                  \
            mquant = v->altpq;                                 \
        if ((edges&4) && s->mb_x == (s->mb_width - 1))         \
            mquant = v->altpq;                                 \
        if ((edges&8) && s->mb_y == (s->mb_height - 1))        \
            mquant = v->altpq;                                 \
        if (!mquant || mquant > 31) {                          \
            av_log(v->s.avctx, AV_LOG_ERROR,                   \
                   "Overriding invalid mquant %d\n", mquant);  \
            mquant = 1;                                        \
        }                                                      \
    }

/**
 * @def GET_MVDATA(_dmv_x, _dmv_y)
 * @brief Get MV differentials
 * @see MVDATA decoding from 8.3.5.2, p(1)20
 * @param _dmv_x Horizontal differential for decoded MV
 * @param _dmv_y Vertical differential for decoded MV
 */
#define GET_MVDATA(_dmv_x, _dmv_y)                                      \
    index = 1 + get_vlc2(gb, ff_vc1_mv_diff_vlc[s->mv_table_index].table, \
                         VC1_MV_DIFF_VLC_BITS, 2);                      \
    if (index > 36) {                                                   \
        mb_has_coeffs = 1;                                              \
        index -= 37;                                                    \
    } else                                                              \
        mb_has_coeffs = 0;                                              \
    s->mb_intra = 0;                                                    \
    if (!index) {                                                       \
        _dmv_x = _dmv_y = 0;                                            \
    } else if (index == 35) {                                           \
        _dmv_x = get_bits(gb, v->k_x - 1 + s->quarter_sample);          \
        _dmv_y = get_bits(gb, v->k_y - 1 + s->quarter_sample);          \
    } else if (index == 36) {                                           \
        _dmv_x = 0;                                                     \
        _dmv_y = 0;                                                     \
        s->mb_intra = 1;                                                \
    } else {                                                            \
        index1 = index % 6;                                             \
        if (!s->quarter_sample && index1 == 5) val = 1;                 \
        else                                   val = 0;                 \
        if (size_table[index1] - val > 0)                               \
            val = get_bits(gb, size_table[index1] - val);               \
        else                                   val = 0;                 \
        sign = 0 - (val&1);                                             \
        _dmv_x = (sign ^ ((val>>1) + offset_table[index1])) - sign;     \
                                                                        \
        index1 = index / 6;                                             \
        if (!s->quarter_sample && index1 == 5) val = 1;                 \
        else                                   val = 0;                 \
        if (size_table[index1] - val > 0)                               \
            val = get_bits(gb, size_table[index1] - val);               \
        else                                   val = 0;                 \
        sign = 0 - (val & 1);                                           \
        _dmv_y = (sign ^ ((val >> 1) + offset_table[index1])) - sign;   \
    }

static av_always_inline void get_mvdata_interlaced(VC1Context *v, int *dmv_x,
                                                   int *dmv_y, int *pred_flag)
{
    int index, index1;
    int extend_x = 0, extend_y = 0;
    GetBitContext *gb = &v->s.gb;
    int bits, esc;
    int val, sign;
    const int* offs_tab;

    if (v->numref) {
        bits = VC1_2REF_MVDATA_VLC_BITS;
        esc  = 125;
    } else {
        bits = VC1_1REF_MVDATA_VLC_BITS;
        esc  = 71;
    }
    switch (v->dmvrange) {
    case 1:
        extend_x = 1;
        break;
    case 2:
        extend_y = 1;
        break;
    case 3:
        extend_x = extend_y = 1;
        break;
    }
    index = get_vlc2(gb, v->imv_vlc->table, bits, 3);
    if (index == esc) {
        *dmv_x = get_bits(gb, v->k_x);
        *dmv_y = get_bits(gb, v->k_y);
        if (v->numref) {
            if (pred_flag) {
                *pred_flag = *dmv_y & 1;
                *dmv_y     = (*dmv_y + *pred_flag) >> 1;
            } else {
                *dmv_y     = (*dmv_y + (*dmv_y & 1)) >> 1;
            }
        }
    }
    else {
        av_assert0(index < esc);
        if (extend_x)
            offs_tab = offset_table2;
        else
            offs_tab = offset_table1;
        index1 = (index + 1) % 9;
        if (index1 != 0) {
            val    = get_bits(gb, index1 + extend_x);
            sign   = 0 -(val & 1);
            *dmv_x = (sign ^ ((val >> 1) + offs_tab[index1])) - sign;
        } else
            *dmv_x = 0;
        if (extend_y)
            offs_tab = offset_table2;
        else
            offs_tab = offset_table1;
        index1 = (index + 1) / 9;
        if (index1 > v->numref) {
            val    = get_bits(gb, (index1 + (extend_y << v->numref)) >> v->numref);
            sign   = 0 - (val & 1);
            *dmv_y = (sign ^ ((val >> 1) + offs_tab[index1 >> v->numref])) - sign;
        } else
            *dmv_y = 0;
        if (v->numref && pred_flag)
            *pred_flag = index1 & 1;
    }
}

static av_always_inline int scaleforsame_x(VC1Context *v, int n /* MV */, int dir)
{
    int scaledvalue, refdist;
    int scalesame1, scalesame2;
    int scalezone1_x, zone1offset_x;
    int table_index = dir ^ v->second_field;

    if (v->s.pict_type != AV_PICTURE_TYPE_B)
        refdist = v->refdist;
    else
        refdist = dir ? v->brfd : v->frfd;
    if (refdist > 3)
        refdist = 3;
    scalesame1    = ff_vc1_field_mvpred_scales[table_index][1][refdist];
    scalesame2    = ff_vc1_field_mvpred_scales[table_index][2][refdist];
    scalezone1_x  = ff_vc1_field_mvpred_scales[table_index][3][refdist];
    zone1offset_x = ff_vc1_field_mvpred_scales[table_index][5][refdist];

    if (FFABS(n) > 255)
        scaledvalue = n;
    else {
        if (FFABS(n) < scalezone1_x)
            scaledvalue = (n * scalesame1) >> 8;
        else {
            if (n < 0)
                scaledvalue = ((n * scalesame2) >> 8) - zone1offset_x;
            else
                scaledvalue = ((n * scalesame2) >> 8) + zone1offset_x;
        }
    }
    return av_clip(scaledvalue, -v->range_x, v->range_x - 1);
}

static av_always_inline int scaleforsame_y(VC1Context *v, int i, int n /* MV */, int dir)
{
    int scaledvalue, refdist;
    int scalesame1, scalesame2;
    int scalezone1_y, zone1offset_y;
    int table_index = dir ^ v->second_field;

    if (v->s.pict_type != AV_PICTURE_TYPE_B)
        refdist = v->refdist;
    else
        refdist = dir ? v->brfd : v->frfd;
    if (refdist > 3)
        refdist = 3;
    scalesame1    = ff_vc1_field_mvpred_scales[table_index][1][refdist];
    scalesame2    = ff_vc1_field_mvpred_scales[table_index][2][refdist];
    scalezone1_y  = ff_vc1_field_mvpred_scales[table_index][4][refdist];
    zone1offset_y = ff_vc1_field_mvpred_scales[table_index][6][refdist];

    if (FFABS(n) > 63)
        scaledvalue = n;
    else {
        if (FFABS(n) < scalezone1_y)
            scaledvalue = (n * scalesame1) >> 8;
        else {
            if (n < 0)
                scaledvalue = ((n * scalesame2) >> 8) - zone1offset_y;
            else
                scaledvalue = ((n * scalesame2) >> 8) + zone1offset_y;
        }
    }

    if (v->cur_field_type && !v->ref_field_type[dir])
        return av_clip(scaledvalue, -v->range_y / 2 + 1, v->range_y / 2);
    else
        return av_clip(scaledvalue, -v->range_y / 2, v->range_y / 2 - 1);
}

static av_always_inline int scaleforopp_x(VC1Context *v, int n /* MV */)
{
    int scalezone1_x, zone1offset_x;
    int scaleopp1, scaleopp2, brfd;
    int scaledvalue;

    brfd = FFMIN(v->brfd, 3);
    scalezone1_x  = ff_vc1_b_field_mvpred_scales[3][brfd];
    zone1offset_x = ff_vc1_b_field_mvpred_scales[5][brfd];
    scaleopp1     = ff_vc1_b_field_mvpred_scales[1][brfd];
    scaleopp2     = ff_vc1_b_field_mvpred_scales[2][brfd];

    if (FFABS(n) > 255)
        scaledvalue = n;
    else {
        if (FFABS(n) < scalezone1_x)
            scaledvalue = (n * scaleopp1) >> 8;
        else {
            if (n < 0)
                scaledvalue = ((n * scaleopp2) >> 8) - zone1offset_x;
            else
                scaledvalue = ((n * scaleopp2) >> 8) + zone1offset_x;
        }
    }
    return av_clip(scaledvalue, -v->range_x, v->range_x - 1);
}

static av_always_inline int scaleforopp_y(VC1Context *v, int n /* MV */, int dir)
{
    int scalezone1_y, zone1offset_y;
    int scaleopp1, scaleopp2, brfd;
    int scaledvalue;

    brfd = FFMIN(v->brfd, 3);
    scalezone1_y  = ff_vc1_b_field_mvpred_scales[4][brfd];
    zone1offset_y = ff_vc1_b_field_mvpred_scales[6][brfd];
    scaleopp1     = ff_vc1_b_field_mvpred_scales[1][brfd];
    scaleopp2     = ff_vc1_b_field_mvpred_scales[2][brfd];

    if (FFABS(n) > 63)
        scaledvalue = n;
    else {
        if (FFABS(n) < scalezone1_y)
            scaledvalue = (n * scaleopp1) >> 8;
        else {
            if (n < 0)
                scaledvalue = ((n * scaleopp2) >> 8) - zone1offset_y;
            else
                scaledvalue = ((n * scaleopp2) >> 8) + zone1offset_y;
        }
    }
    if (v->cur_field_type && !v->ref_field_type[dir]) {
        return av_clip(scaledvalue, -v->range_y / 2 + 1, v->range_y / 2);
    } else {
        return av_clip(scaledvalue, -v->range_y / 2, v->range_y / 2 - 1);
    }
}

static av_always_inline int scaleforsame(VC1Context *v, int i, int n /* MV */,
                                         int dim, int dir)
{
    int brfd, scalesame;
    int hpel = 1 - v->s.quarter_sample;

    n >>= hpel;
    if (v->s.pict_type != AV_PICTURE_TYPE_B || v->second_field || !dir) {
        if (dim)
            n = scaleforsame_y(v, i, n, dir) << hpel;
        else
            n = scaleforsame_x(v, n, dir) << hpel;
        return n;
    }
    brfd      = FFMIN(v->brfd, 3);
    scalesame = ff_vc1_b_field_mvpred_scales[0][brfd];

    n = (n * scalesame >> 8) << hpel;
    return n;
}

static av_always_inline int scaleforopp(VC1Context *v, int n /* MV */,
                                        int dim, int dir)
{
    int refdist, scaleopp;
    int hpel = 1 - v->s.quarter_sample;

    n >>= hpel;
    if (v->s.pict_type == AV_PICTURE_TYPE_B && !v->second_field && dir == 1) {
        if (dim)
            n = scaleforopp_y(v, n, dir) << hpel;
        else
            n = scaleforopp_x(v, n) << hpel;
        return n;
    }
    if (v->s.pict_type != AV_PICTURE_TYPE_B)
        refdist = FFMIN(v->refdist, 3);
    else
        refdist = dir ? v->brfd : v->frfd;
    scaleopp = ff_vc1_field_mvpred_scales[dir ^ v->second_field][0][refdist];

    n = (n * scaleopp >> 8) << hpel;
    return n;
}

/** Predict and set motion vector
 */
static inline void vc1_pred_mv(VC1Context *v, int n, int dmv_x, int dmv_y,
                               int mv1, int r_x, int r_y, uint8_t* is_intra,
                               int pred_flag, int dir)
{
    MpegEncContext *s = &v->s;
    int xy, wrap, off = 0;
    int16_t *A, *B, *C;
    int px, py;
    int sum;
    int mixedmv_pic, num_samefield = 0, num_oppfield = 0;
    int opposite, a_f, b_f, c_f;
    int16_t field_predA[2];
    int16_t field_predB[2];
    int16_t field_predC[2];
    int a_valid, b_valid, c_valid;
    int hybridmv_thresh, y_bias = 0;

    if (v->mv_mode == MV_PMODE_MIXED_MV ||
        ((v->mv_mode == MV_PMODE_INTENSITY_COMP) && (v->mv_mode2 == MV_PMODE_MIXED_MV)))
        mixedmv_pic = 1;
    else
        mixedmv_pic = 0;
    /* scale MV difference to be quad-pel */
    dmv_x <<= 1 - s->quarter_sample;
    dmv_y <<= 1 - s->quarter_sample;

    wrap = s->b8_stride;
    xy   = s->block_index[n];

    if (s->mb_intra) {
        s->mv[0][n][0] = s->current_picture.motion_val[0][xy + v->blocks_off][0] = 0;
        s->mv[0][n][1] = s->current_picture.motion_val[0][xy + v->blocks_off][1] = 0;
        s->current_picture.motion_val[1][xy + v->blocks_off][0] = 0;
        s->current_picture.motion_val[1][xy + v->blocks_off][1] = 0;
        if (mv1) { /* duplicate motion data for 1-MV block */
            s->current_picture.motion_val[0][xy + 1 + v->blocks_off][0]        = 0;
            s->current_picture.motion_val[0][xy + 1 + v->blocks_off][1]        = 0;
            s->current_picture.motion_val[0][xy + wrap + v->blocks_off][0]     = 0;
            s->current_picture.motion_val[0][xy + wrap + v->blocks_off][1]     = 0;
            s->current_picture.motion_val[0][xy + wrap + 1 + v->blocks_off][0] = 0;
            s->current_picture.motion_val[0][xy + wrap + 1 + v->blocks_off][1] = 0;
            v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;
            s->current_picture.motion_val[1][xy + 1 + v->blocks_off][0]        = 0;
            s->current_picture.motion_val[1][xy + 1 + v->blocks_off][1]        = 0;
            s->current_picture.motion_val[1][xy + wrap][0]                     = 0;
            s->current_picture.motion_val[1][xy + wrap + v->blocks_off][1]     = 0;
            s->current_picture.motion_val[1][xy + wrap + 1 + v->blocks_off][0] = 0;
            s->current_picture.motion_val[1][xy + wrap + 1 + v->blocks_off][1] = 0;
        }
        return;
    }

    C = s->current_picture.motion_val[dir][xy -    1 + v->blocks_off];
    A = s->current_picture.motion_val[dir][xy - wrap + v->blocks_off];
    if (mv1) {
        if (v->field_mode && mixedmv_pic)
            off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;
        else
            off = (s->mb_x == (s->mb_width - 1)) ? -1 : 2;
    } else {
        //in 4-MV mode different blocks have different B predictor position
        switch (n) {
        case 0:
            off = (s->mb_x > 0) ? -1 : 1;
            break;
        case 1:
            off = (s->mb_x == (s->mb_width - 1)) ? -1 : 1;
            break;
        case 2:
            off = 1;
            break;
        case 3:
            off = -1;
        }
    }
    B = s->current_picture.motion_val[dir][xy - wrap + off + v->blocks_off];

    a_valid = !s->first_slice_line || (n == 2 || n == 3);
    b_valid = a_valid && (s->mb_width > 1);
    c_valid = s->mb_x || (n == 1 || n == 3);
    if (v->field_mode) {
        a_valid = a_valid && !is_intra[xy - wrap];
        b_valid = b_valid && !is_intra[xy - wrap + off];
        c_valid = c_valid && !is_intra[xy - 1];
    }

    if (a_valid) {
        a_f = v->mv_f[dir][xy - wrap + v->blocks_off];
        num_oppfield  += a_f;
        num_samefield += 1 - a_f;
        field_predA[0] = A[0];
        field_predA[1] = A[1];
    } else {
        field_predA[0] = field_predA[1] = 0;
        a_f = 0;
    }
    if (b_valid) {
        b_f = v->mv_f[dir][xy - wrap + off + v->blocks_off];
        num_oppfield  += b_f;
        num_samefield += 1 - b_f;
        field_predB[0] = B[0];
        field_predB[1] = B[1];
    } else {
        field_predB[0] = field_predB[1] = 0;
        b_f = 0;
    }
    if (c_valid) {
        c_f = v->mv_f[dir][xy - 1 + v->blocks_off];
        num_oppfield  += c_f;
        num_samefield += 1 - c_f;
        field_predC[0] = C[0];
        field_predC[1] = C[1];
    } else {
        field_predC[0] = field_predC[1] = 0;
        c_f = 0;
    }

    if (v->field_mode) {
        if (!v->numref)
            // REFFIELD determines if the last field or the second-last field is
            // to be used as reference
            opposite = 1 - v->reffield;
        else {
            if (num_samefield <= num_oppfield)
                opposite = 1 - pred_flag;
            else
                opposite = pred_flag;
        }
    } else
        opposite = 0;
    if (opposite) {
        if (a_valid && !a_f) {
            field_predA[0] = scaleforopp(v, field_predA[0], 0, dir);
            field_predA[1] = scaleforopp(v, field_predA[1], 1, dir);
        }
        if (b_valid && !b_f) {
            field_predB[0] = scaleforopp(v, field_predB[0], 0, dir);
            field_predB[1] = scaleforopp(v, field_predB[1], 1, dir);
        }
        if (c_valid && !c_f) {
            field_predC[0] = scaleforopp(v, field_predC[0], 0, dir);
            field_predC[1] = scaleforopp(v, field_predC[1], 1, dir);
        }
        v->mv_f[dir][xy + v->blocks_off] = 1;
        v->ref_field_type[dir] = !v->cur_field_type;
    } else {
        if (a_valid && a_f) {
            field_predA[0] = scaleforsame(v, n, field_predA[0], 0, dir);
            field_predA[1] = scaleforsame(v, n, field_predA[1], 1, dir);
        }
        if (b_valid && b_f) {
            field_predB[0] = scaleforsame(v, n, field_predB[0], 0, dir);
            field_predB[1] = scaleforsame(v, n, field_predB[1], 1, dir);
        }
        if (c_valid && c_f) {
            field_predC[0] = scaleforsame(v, n, field_predC[0], 0, dir);
            field_predC[1] = scaleforsame(v, n, field_predC[1], 1, dir);
        }
        v->mv_f[dir][xy + v->blocks_off] = 0;
        v->ref_field_type[dir] = v->cur_field_type;
    }

    if (a_valid) {
        px = field_predA[0];
        py = field_predA[1];
    } else if (c_valid) {
        px = field_predC[0];
        py = field_predC[1];
    } else if (b_valid) {
        px = field_predB[0];
        py = field_predB[1];
    } else {
        px = 0;
        py = 0;
    }

    if (num_samefield + num_oppfield > 1) {
        px = mid_pred(field_predA[0], field_predB[0], field_predC[0]);
        py = mid_pred(field_predA[1], field_predB[1], field_predC[1]);
    }

    /* Pullback MV as specified in 8.3.5.3.4 */
    if (!v->field_mode) {
        int qx, qy, X, Y;
        qx = (s->mb_x << 6) + ((n == 1 || n == 3) ? 32 : 0);
        qy = (s->mb_y << 6) + ((n == 2 || n == 3) ? 32 : 0);
        X  = (s->mb_width  << 6) - 4;
        Y  = (s->mb_height << 6) - 4;
        if (mv1) {
            if (qx + px < -60) px = -60 - qx;
            if (qy + py < -60) py = -60 - qy;
        } else {
            if (qx + px < -28) px = -28 - qx;
            if (qy + py < -28) py = -28 - qy;
        }
        if (qx + px > X) px = X - qx;
        if (qy + py > Y) py = Y - qy;
    }

    if (!v->field_mode || s->pict_type != AV_PICTURE_TYPE_B) {
        /* Calculate hybrid prediction as specified in 8.3.5.3.5 (also 10.3.5.4.3.5) */
        hybridmv_thresh = 32;
        if (a_valid && c_valid) {
            if (is_intra[xy - wrap])
                sum = FFABS(px) + FFABS(py);
            else
                sum = FFABS(px - field_predA[0]) + FFABS(py - field_predA[1]);
            if (sum > hybridmv_thresh) {
                if (get_bits1(&s->gb)) {     // read HYBRIDPRED bit
                    px = field_predA[0];
                    py = field_predA[1];
                } else {
                    px = field_predC[0];
                    py = field_predC[1];
                }
            } else {
                if (is_intra[xy - 1])
                    sum = FFABS(px) + FFABS(py);
                else
                    sum = FFABS(px - field_predC[0]) + FFABS(py - field_predC[1]);
                if (sum > hybridmv_thresh) {
                    if (get_bits1(&s->gb)) {
                        px = field_predA[0];
                        py = field_predA[1];
                    } else {
                        px = field_predC[0];
                        py = field_predC[1];
                    }
                }
            }
        }
    }

    if (v->field_mode && v->numref)
        r_y >>= 1;
    if (v->field_mode && v->cur_field_type && v->ref_field_type[dir] == 0)
        y_bias = 1;
    /* store MV using signed modulus of MV range defined in 4.11 */
    s->mv[dir][n][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0] = ((px + dmv_x + r_x) & ((r_x << 1) - 1)) - r_x;
    s->mv[dir][n][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1] = ((py + dmv_y + r_y - y_bias) & ((r_y << 1) - 1)) - r_y + y_bias;
    if (mv1) { /* duplicate motion data for 1-MV block */
        s->current_picture.motion_val[dir][xy +    1 +     v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];
        s->current_picture.motion_val[dir][xy +    1 +     v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];
        s->current_picture.motion_val[dir][xy + wrap +     v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];
        s->current_picture.motion_val[dir][xy + wrap +     v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];
        s->current_picture.motion_val[dir][xy + wrap + 1 + v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];
        s->current_picture.motion_val[dir][xy + wrap + 1 + v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];
        v->mv_f[dir][xy +    1 + v->blocks_off] = v->mv_f[dir][xy +            v->blocks_off];
        v->mv_f[dir][xy + wrap + v->blocks_off] = v->mv_f[dir][xy + wrap + 1 + v->blocks_off] = v->mv_f[dir][xy + v->blocks_off];
    }
}

/** Predict and set motion vector for interlaced frame picture MBs
 */
static inline void vc1_pred_mv_intfr(VC1Context *v, int n, int dmv_x, int dmv_y,
                                     int mvn, int r_x, int r_y, uint8_t* is_intra, int dir)
{
    MpegEncContext *s = &v->s;
    int xy, wrap, off = 0;
    int A[2], B[2], C[2];
    int px = 0, py = 0;
    int a_valid = 0, b_valid = 0, c_valid = 0;
    int field_a, field_b, field_c; // 0: same, 1: opposit
    int total_valid, num_samefield, num_oppfield;
    int pos_c, pos_b, n_adj;

    wrap = s->b8_stride;
    xy = s->block_index[n];

    if (s->mb_intra) {
        s->mv[0][n][0] = s->current_picture.motion_val[0][xy][0] = 0;
        s->mv[0][n][1] = s->current_picture.motion_val[0][xy][1] = 0;
        s->current_picture.motion_val[1][xy][0] = 0;
        s->current_picture.motion_val[1][xy][1] = 0;
        if (mvn == 1) { /* duplicate motion data for 1-MV block */
            s->current_picture.motion_val[0][xy + 1][0]        = 0;
            s->current_picture.motion_val[0][xy + 1][1]        = 0;
            s->current_picture.motion_val[0][xy + wrap][0]     = 0;
            s->current_picture.motion_val[0][xy + wrap][1]     = 0;
            s->current_picture.motion_val[0][xy + wrap + 1][0] = 0;
            s->current_picture.motion_val[0][xy + wrap + 1][1] = 0;
            v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;
            s->current_picture.motion_val[1][xy + 1][0]        = 0;
            s->current_picture.motion_val[1][xy + 1][1]        = 0;
            s->current_picture.motion_val[1][xy + wrap][0]     = 0;
            s->current_picture.motion_val[1][xy + wrap][1]     = 0;
            s->current_picture.motion_val[1][xy + wrap + 1][0] = 0;
            s->current_picture.motion_val[1][xy + wrap + 1][1] = 0;
        }
        return;
    }

    off = ((n == 0) || (n == 1)) ? 1 : -1;
    /* predict A */
    if (s->mb_x || (n == 1) || (n == 3)) {
        if ((v->blk_mv_type[xy]) // current block (MB) has a field MV
            || (!v->blk_mv_type[xy] && !v->blk_mv_type[xy - 1])) { // or both have frame MV
            A[0] = s->current_picture.motion_val[dir][xy - 1][0];
            A[1] = s->current_picture.motion_val[dir][xy - 1][1];
            a_valid = 1;
        } else { // current block has frame mv and cand. has field MV (so average)
            A[0] = (s->current_picture.motion_val[dir][xy - 1][0]
                    + s->current_picture.motion_val[dir][xy - 1 + off * wrap][0] + 1) >> 1;
            A[1] = (s->current_picture.motion_val[dir][xy - 1][1]
                    + s->current_picture.motion_val[dir][xy - 1 + off * wrap][1] + 1) >> 1;
            a_valid = 1;
        }
        if (!(n & 1) && v->is_intra[s->mb_x - 1]) {
            a_valid = 0;
            A[0] = A[1] = 0;
        }
    } else
        A[0] = A[1] = 0;
    /* Predict B and C */
    B[0] = B[1] = C[0] = C[1] = 0;
    if (n == 0 || n == 1 || v->blk_mv_type[xy]) {
        if (!s->first_slice_line) {
            if (!v->is_intra[s->mb_x - s->mb_stride]) {
                b_valid = 1;
                n_adj   = n | 2;
                pos_b   = s->block_index[n_adj] - 2 * wrap;
                if (v->blk_mv_type[pos_b] && v->blk_mv_type[xy]) {
                    n_adj = (n & 2) | (n & 1);
                }
                B[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap][0];
                B[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap][1];
                if (v->blk_mv_type[pos_b] && !v->blk_mv_type[xy]) {
                    B[0] = (B[0] + s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap][0] + 1) >> 1;
                    B[1] = (B[1] + s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap][1] + 1) >> 1;
                }
            }
            if (s->mb_width > 1) {
                if (!v->is_intra[s->mb_x - s->mb_stride + 1]) {
                    c_valid = 1;
                    n_adj   = 2;
                    pos_c   = s->block_index[2] - 2 * wrap + 2;
                    if (v->blk_mv_type[pos_c] && v->blk_mv_type[xy]) {
                        n_adj = n & 2;
                    }
                    C[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap + 2][0];
                    C[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap + 2][1];
                    if (v->blk_mv_type[pos_c] && !v->blk_mv_type[xy]) {
                        C[0] = (1 + C[0] + (s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap + 2][0])) >> 1;
                        C[1] = (1 + C[1] + (s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap + 2][1])) >> 1;
                    }
                    if (s->mb_x == s->mb_width - 1) {
                        if (!v->is_intra[s->mb_x - s->mb_stride - 1]) {
                            c_valid = 1;
                            n_adj   = 3;
                            pos_c   = s->block_index[3] - 2 * wrap - 2;
                            if (v->blk_mv_type[pos_c] && v->blk_mv_type[xy]) {
                                n_adj = n | 1;
                            }
                            C[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap - 2][0];
                            C[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap - 2][1];
                            if (v->blk_mv_type[pos_c] && !v->blk_mv_type[xy]) {
                                C[0] = (1 + C[0] + s->current_picture.motion_val[dir][s->block_index[1] - 2 * wrap - 2][0]) >> 1;
                                C[1] = (1 + C[1] + s->current_picture.motion_val[dir][s->block_index[1] - 2 * wrap - 2][1]) >> 1;
                            }
                        } else
                            c_valid = 0;
                    }
                }
            }
        }
    } else {
        pos_b   = s->block_index[1];
        b_valid = 1;
        B[0]    = s->current_picture.motion_val[dir][pos_b][0];
        B[1]    = s->current_picture.motion_val[dir][pos_b][1];
        pos_c   = s->block_index[0];
        c_valid = 1;
        C[0]    = s->current_picture.motion_val[dir][pos_c][0];
        C[1]    = s->current_picture.motion_val[dir][pos_c][1];
    }

    total_valid = a_valid + b_valid + c_valid;
    // check if predictor A is out of bounds
    if (!s->mb_x && !(n == 1 || n == 3)) {
        A[0] = A[1] = 0;
    }
    // check if predictor B is out of bounds
    if ((s->first_slice_line && v->blk_mv_type[xy]) || (s->first_slice_line && !(n & 2))) {
        B[0] = B[1] = C[0] = C[1] = 0;
    }
    if (!v->blk_mv_type[xy]) {
        if (s->mb_width == 1) {
            px = B[0];
            py = B[1];
        } else {
            if (total_valid >= 2) {
                px = mid_pred(A[0], B[0], C[0]);
                py = mid_pred(A[1], B[1], C[1]);
            } else if (total_valid) {
                if      (a_valid) { px = A[0]; py = A[1]; }
                else if (b_valid) { px = B[0]; py = B[1]; }
                else if (c_valid) { px = C[0]; py = C[1]; }
                else av_assert2(0);
            }
        }
    } else {
        if (a_valid)
            field_a = (A[1] & 4) ? 1 : 0;
        else
            field_a = 0;
        if (b_valid)
            field_b = (B[1] & 4) ? 1 : 0;
        else
            field_b = 0;
        if (c_valid)
            field_c = (C[1] & 4) ? 1 : 0;
        else
            field_c = 0;

        num_oppfield  = field_a + field_b + field_c;
        num_samefield = total_valid - num_oppfield;
        if (total_valid == 3) {
            if ((num_samefield == 3) || (num_oppfield == 3)) {
                px = mid_pred(A[0], B[0], C[0]);
                py = mid_pred(A[1], B[1], C[1]);
            } else if (num_samefield >= num_oppfield) {
                /* take one MV from same field set depending on priority
                the check for B may not be necessary */
                px = !field_a ? A[0] : B[0];
                py = !field_a ? A[1] : B[1];
            } else {
                px =  field_a ? A[0] : B[0];
                py =  field_a ? A[1] : B[1];
            }
        } else if (total_valid == 2) {
            if (num_samefield >= num_oppfield) {
                if (!field_a && a_valid) {
                    px = A[0];
                    py = A[1];
                } else if (!field_b && b_valid) {
                    px = B[0];
                    py = B[1];
                } else /*if (c_valid)*/ {
                    av_assert1(c_valid);
                    px = C[0];
                    py = C[1];
                } /*else px = py = 0;*/
            } else {
                if (field_a && a_valid) {
                    px = A[0];
                    py = A[1];
                } else /*if (field_b && b_valid)*/ {
                    av_assert1(field_b && b_valid);
                    px = B[0];
                    py = B[1];
                } /*else if (c_valid) {
                    px = C[0];
                    py = C[1];
                }*/
            }
        } else if (total_valid == 1) {
            px = (a_valid) ? A[0] : ((b_valid) ? B[0] : C[0]);
            py = (a_valid) ? A[1] : ((b_valid) ? B[1] : C[1]);
        }
    }

    /* store MV using signed modulus of MV range defined in 4.11 */
    s->mv[dir][n][0] = s->current_picture.motion_val[dir][xy][0] = ((px + dmv_x + r_x) & ((r_x << 1) - 1)) - r_x;
    s->mv[dir][n][1] = s->current_picture.motion_val[dir][xy][1] = ((py + dmv_y + r_y) & ((r_y << 1) - 1)) - r_y;
    if (mvn == 1) { /* duplicate motion data for 1-MV block */
        s->current_picture.motion_val[dir][xy +    1    ][0] = s->current_picture.motion_val[dir][xy][0];
        s->current_picture.motion_val[dir][xy +    1    ][1] = s->current_picture.motion_val[dir][xy][1];
        s->current_picture.motion_val[dir][xy + wrap    ][0] = s->current_picture.motion_val[dir][xy][0];
        s->current_picture.motion_val[dir][xy + wrap    ][1] = s->current_picture.motion_val[dir][xy][1];
        s->current_picture.motion_val[dir][xy + wrap + 1][0] = s->current_picture.motion_val[dir][xy][0];
        s->current_picture.motion_val[dir][xy + wrap + 1][1] = s->current_picture.motion_val[dir][xy][1];
    } else if (mvn == 2) { /* duplicate motion data for 2-Field MV block */
        s->current_picture.motion_val[dir][xy + 1][0] = s->current_picture.motion_val[dir][xy][0];
        s->current_picture.motion_val[dir][xy + 1][1] = s->current_picture.motion_val[dir][xy][1];
        s->mv[dir][n + 1][0] = s->mv[dir][n][0];
        s->mv[dir][n + 1][1] = s->mv[dir][n][1];
    }
}

/** Motion compensation for direct or interpolated blocks in B-frames
 */
static void vc1_interp_mc(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    H264ChromaContext *h264chroma = &v->h264chroma;
    uint8_t *srcY, *srcU, *srcV;
    int dxy, mx, my, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y;
    int off, off_uv;
    int v_edge_pos = s->v_edge_pos >> v->field_mode;
    int use_ic = v->next_use_ic;

    if (!v->field_mode && !v->s.next_picture.f.data[0])
        return;

    mx   = s->mv[1][0][0];
    my   = s->mv[1][0][1];
    uvmx = (mx + ((mx & 3) == 3)) >> 1;
    uvmy = (my + ((my & 3) == 3)) >> 1;
    if (v->field_mode) {
        if (v->cur_field_type != v->ref_field_type[1])
            my   = my   - 2 + 4 * v->cur_field_type;
            uvmy = uvmy - 2 + 4 * v->cur_field_type;
    }
    if (v->fastuvmc) {
        uvmx = uvmx + ((uvmx < 0) ? -(uvmx & 1) : (uvmx & 1));
        uvmy = uvmy + ((uvmy < 0) ? -(uvmy & 1) : (uvmy & 1));
    }
    srcY = s->next_picture.f.data[0];
    srcU = s->next_picture.f.data[1];
    srcV = s->next_picture.f.data[2];

    src_x   = s->mb_x * 16 + (mx   >> 2);
    src_y   = s->mb_y * 16 + (my   >> 2);
    uvsrc_x = s->mb_x *  8 + (uvmx >> 2);
    uvsrc_y = s->mb_y *  8 + (uvmy >> 2);

    if (v->profile != PROFILE_ADVANCED) {
        src_x   = av_clip(  src_x, -16, s->mb_width  * 16);
        src_y   = av_clip(  src_y, -16, s->mb_height * 16);
        uvsrc_x = av_clip(uvsrc_x,  -8, s->mb_width  *  8);
        uvsrc_y = av_clip(uvsrc_y,  -8, s->mb_height *  8);
    } else {
        src_x   = av_clip(  src_x, -17, s->avctx->coded_width);
        src_y   = av_clip(  src_y, -18, s->avctx->coded_height + 1);
        uvsrc_x = av_clip(uvsrc_x,  -8, s->avctx->coded_width  >> 1);
        uvsrc_y = av_clip(uvsrc_y,  -8, s->avctx->coded_height >> 1);
    }

    srcY += src_y   * s->linesize   + src_x;
    srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
    srcV += uvsrc_y * s->uvlinesize + uvsrc_x;

    if (v->field_mode && v->ref_field_type[1]) {
        srcY += s->current_picture_ptr->f.linesize[0];
        srcU += s->current_picture_ptr->f.linesize[1];
        srcV += s->current_picture_ptr->f.linesize[2];
    }

    /* for grayscale we should not try to read from unknown area */
    if (s->flags & CODEC_FLAG_GRAY) {
        srcU = s->edge_emu_buffer + 18 * s->linesize;
        srcV = s->edge_emu_buffer + 18 * s->linesize;
    }

    if (v->rangeredfrm || s->h_edge_pos < 22 || v_edge_pos < 22 || use_ic
        || (unsigned)(src_x - 1) > s->h_edge_pos - (mx & 3) - 16 - 3
        || (unsigned)(src_y - 1) > v_edge_pos    - (my & 3) - 16 - 3) {
        uint8_t *uvbuf = s->edge_emu_buffer + 19 * s->linesize;

        srcY -= s->mspel * (1 + s->linesize);
        s->vdsp.emulated_edge_mc(s->edge_emu_buffer, s->linesize, srcY, s->linesize,
                                 17 + s->mspel * 2, 17 + s->mspel * 2,
                                 src_x - s->mspel, src_y - s->mspel,
                                 s->h_edge_pos, v_edge_pos);
        srcY = s->edge_emu_buffer;
        s->vdsp.emulated_edge_mc(uvbuf, s->uvlinesize, srcU, s->uvlinesize,
                                 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        s->vdsp.emulated_edge_mc(uvbuf + 16, s->uvlinesize, srcV, s->uvlinesize,
                                 8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                 s->h_edge_pos >> 1, v_edge_pos >> 1);
        srcU = uvbuf;
        srcV = uvbuf + 16;
        /* if we deal with range reduction we need to scale source blocks */
        if (v->rangeredfrm) {
            int i, j;
            uint8_t *src, *src2;

            src = srcY;
            for (j = 0; j < 17 + s->mspel * 2; j++) {
                for (i = 0; i < 17 + s->mspel * 2; i++)
                    src[i] = ((src[i] - 128) >> 1) + 128;
                src += s->linesize;
            }
            src = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                for (i = 0; i < 9; i++) {
                    src[i]  = ((src[i]  - 128) >> 1) + 128;
                    src2[i] = ((src2[i] - 128) >> 1) + 128;
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }

        if (use_ic) {
            uint8_t (*luty )[256] = v->next_luty;
            uint8_t (*lutuv)[256] = v->next_lutuv;
            int i, j;
            uint8_t *src, *src2;

            src = srcY;
            for (j = 0; j < 17 + s->mspel * 2; j++) {
                int f = v->field_mode ? v->ref_field_type[1] : ((j+src_y - s->mspel) & 1);
                for (i = 0; i < 17 + s->mspel * 2; i++)
                    src[i] = luty[f][src[i]];
                src += s->linesize;
            }
            src  = srcU;
            src2 = srcV;
            for (j = 0; j < 9; j++) {
                int f = v->field_mode ? v->ref_field_type[1] : ((j+uvsrc_y) & 1);
                for (i = 0; i < 9; i++) {
                    src[i]  = lutuv[f][src[i]];
                    src2[i] = lutuv[f][src2[i]];
                }
                src  += s->uvlinesize;
                src2 += s->uvlinesize;
            }
        }
        srcY += s->mspel * (1 + s->linesize);
    }

    off    = 0;
    off_uv = 0;

    if (s->mspel) {
        dxy = ((my & 3) << 2) | (mx & 3);
        v->vc1dsp.avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + off    , srcY    , s->linesize, v->rnd);
        v->vc1dsp.avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + off + 8, srcY + 8, s->linesize, v->rnd);
        srcY += s->linesize * 8;
        v->vc1dsp.avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + off + 8 * s->linesize    , srcY    , s->linesize, v->rnd);
        v->vc1dsp.avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + off + 8 * s->linesize + 8, srcY + 8, s->linesize, v->rnd);
    } else { // hpel mc
        dxy = (my & 2) | ((mx & 2) >> 1);

        if (!v->rnd)
            s->hdsp.avg_pixels_tab[0][dxy](s->dest[0] + off, srcY, s->linesize, 16);
        else
            s->hdsp.avg_no_rnd_pixels_tab[dxy](s->dest[0] + off, srcY, s->linesize, 16);
    }

    if (s->flags & CODEC_FLAG_GRAY) return;
    /* Chroma MC always uses qpel blilinear */
    uvmx = (uvmx & 3) << 1;
    uvmy = (uvmy & 3) << 1;
    if (!v->rnd) {
        h264chroma->avg_h264_chroma_pixels_tab[0](s->dest[1] + off_uv, srcU, s->uvlinesize, 8, uvmx, uvmy);
        h264chroma->avg_h264_chroma_pixels_tab[0](s->dest[2] + off_uv, srcV, s->uvlinesize, 8, uvmx, uvmy);
    } else {
        v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1] + off_uv, srcU, s->uvlinesize, 8, uvmx, uvmy);
        v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2] + off_uv, srcV, s->uvlinesize, 8, uvmx, uvmy);
    }
}

static av_always_inline int scale_mv(int value, int bfrac, int inv, int qs)
{
    int n = bfrac;

#if B_FRACTION_DEN==256
    if (inv)
        n -= 256;
    if (!qs)
        return 2 * ((value * n + 255) >> 9);
    return (value * n + 128) >> 8;
#else
    if (inv)
        n -= B_FRACTION_DEN;
    if (!qs)
        return 2 * ((value * n + B_FRACTION_DEN - 1) / (2 * B_FRACTION_DEN));
    return (value * n + B_FRACTION_DEN/2) / B_FRACTION_DEN;
#endif
}

/** Reconstruct motion vector for B-frame and do motion compensation
 */
static inline void vc1_b_mc(VC1Context *v, int dmv_x[2], int dmv_y[2],
                            int direct, int mode)
{
    if (direct) {
        vc1_mc_1mv(v, 0);
        vc1_interp_mc(v);
        return;
    }
    if (mode == BMV_TYPE_INTERPOLATED) {
        vc1_mc_1mv(v, 0);
        vc1_interp_mc(v);
        return;
    }

    vc1_mc_1mv(v, (mode == BMV_TYPE_BACKWARD));
}

static inline void vc1_pred_b_mv(VC1Context *v, int dmv_x[2], int dmv_y[2],
                                 int direct, int mvtype)
{
    MpegEncContext *s = &v->s;
    int xy, wrap, off = 0;
    int16_t *A, *B, *C;
    int px, py;
    int sum;
    int r_x, r_y;
    const uint8_t *is_intra = v->mb_type[0];

    r_x = v->range_x;
    r_y = v->range_y;
    /* scale MV difference to be quad-pel */
    dmv_x[0] <<= 1 - s->quarter_sample;
    dmv_y[0] <<= 1 - s->quarter_sample;
    dmv_x[1] <<= 1 - s->quarter_sample;
    dmv_y[1] <<= 1 - s->quarter_sample;

    wrap = s->b8_stride;
    xy = s->block_index[0];

    if (s->mb_intra) {
        s->current_picture.motion_val[0][xy + v->blocks_off][0] =
        s->current_picture.motion_val[0][xy + v->blocks_off][1] =
        s->current_picture.motion_val[1][xy + v->blocks_off][0] =
        s->current_picture.motion_val[1][xy + v->blocks_off][1] = 0;
        return;
    }
    if (!v->field_mode) {
        s->mv[0][0][0] = scale_mv(s->next_picture.motion_val[1][xy][0], v->bfraction, 0, s->quarter_sample);
        s->mv[0][0][1] = scale_mv(s->next_picture.motion_val[1][xy][1], v->bfraction, 0, s->quarter_sample);
        s->mv[1][0][0] = scale_mv(s->next_picture.motion_val[1][xy][0], v->bfraction, 1, s->quarter_sample);
        s->mv[1][0][1] = scale_mv(s->next_picture.motion_val[1][xy][1], v->bfraction, 1, s->quarter_sample);

        /* Pullback predicted motion vectors as specified in 8.4.5.4 */
        s->mv[0][0][0] = av_clip(s->mv[0][0][0], -60 - (s->mb_x << 6), (s->mb_width  << 6) - 4 - (s->mb_x << 6));
        s->mv[0][0][1] = av_clip(s->mv[0][0][1], -60 - (s->mb_y << 6), (s->mb_height << 6) - 4 - (s->mb_y << 6));
        s->mv[1][0][0] = av_clip(s->mv[1][0][0], -60 - (s->mb_x << 6), (s->mb_width  << 6) - 4 - (s->mb_x << 6));
        s->mv[1][0][1] = av_clip(s->mv[1][0][1], -60 - (s->mb_y << 6), (s->mb_height << 6) - 4 - (s->mb_y << 6));
    }
    if (direct) {
        s->current_picture.motion_val[0][xy + v->blocks_off][0] = s->mv[0][0][0];
        s->current_picture.motion_val[0][xy + v->blocks_off][1] = s->mv[0][0][1];
        s->current_picture.motion_val[1][xy + v->blocks_off][0] = s->mv[1][0][0];
        s->current_picture.motion_val[1][xy + v->blocks_off][1] = s->mv[1][0][1];
        return;
    }

    if ((mvtype == BMV_TYPE_FORWARD) || (mvtype == BMV_TYPE_INTERPOLATED)) {
        C   = s->current_picture.motion_val[0][xy - 2];
        A   = s->current_picture.motion_val[0][xy - wrap * 2];
        off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;
        B   = s->current_picture.motion_val[0][xy - wrap * 2 + off];

        if (!s->mb_x) C[0] = C[1] = 0;
        if (!s->first_slice_line) { // predictor A is not out of bounds
            if (s->mb_width == 1) {
                px = A[0];
                py = A[1];
            } else {
                px = mid_pred(A[0], B[0], C[0]);
                py = mid_pred(A[1], B[1], C[1]);
            }
        } else if (s->mb_x) { // predictor C is not out of bounds
            px = C[0];
            py = C[1];
        } else {
            px = py = 0;
        }
        /* Pullback MV as specified in 8.3.5.3.4 */
        {
            int qx, qy, X, Y;
            if (v->profile < PROFILE_ADVANCED) {
                qx = (s->mb_x << 5);
                qy = (s->mb_y << 5);
                X  = (s->mb_width  << 5) - 4;
                Y  = (s->mb_height << 5) - 4;
                if (qx + px < -28) px = -28 - qx;
                if (qy + py < -28) py = -28 - qy;
                if (qx + px > X) px = X - qx;
                if (qy + py > Y) py = Y - qy;
            } else {
                qx = (s->mb_x << 6);
                qy = (s->mb_y << 6);
                X  = (s->mb_width  << 6) - 4;
                Y  = (s->mb_height << 6) - 4;
                if (qx + px < -60) px = -60 - qx;
                if (qy + py < -60) py = -60 - qy;
                if (qx + px > X) px = X - qx;
                if (qy + py > Y) py = Y - qy;
            }
        }
        /* Calculate hybrid prediction as specified in 8.3.5.3.5 */
        if (0 && !s->first_slice_line && s->mb_x) {
            if (is_intra[xy - wrap])
                sum = FFABS(px) + FFABS(py);
            else
                sum = FFABS(px - A[0]) + FFABS(py - A[1]);
            if (sum > 32) {
                if (get_bits1(&s->gb)) {
                    px = A[0];
                    py = A[1];
                } else {
                    px = C[0];
                    py = C[1];
                }
            } else {
                if (is_intra[xy - 2])
                    sum = FFABS(px) + FFABS(py);
                else
                    sum = FFABS(px - C[0]) + FFABS(py - C[1]);
                if (sum > 32) {
                    if (get_bits1(&s->gb)) {
                        px = A[0];
                        py = A[1];
                    } else {
                        px = C[0];
                        py = C[1];
                    }
                }
            }
        }
        /* store MV using signed modulus of MV range defined in 4.11 */
        s->mv[0][0][0] = ((px + dmv_x[0] + r_x) & ((r_x << 1) - 1)) - r_x;
        s->mv[0][0][1] = ((py + dmv_y[0] + r_y) & ((r_y << 1) - 1)) - r_y;
    }
    if ((mvtype == BMV_TYPE_BACKWARD) || (mvtype == BMV_TYPE_INTERPOLATED)) {
        C   = s->current_picture.motion_val[1][xy - 2];
        A   = s->current_picture.motion_val[1][xy - wrap * 2];
        off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;
        B   = s->current_picture.motion_val[1][xy - wrap * 2 + off];

        if (!s->mb_x)
            C[0] = C[1] = 0;
        if (!s->first_slice_line) { // predictor A is not out of bounds
            if (s->mb_width == 1) {
                px = A[0];
                py = A[1];
            } else {
                px = mid_pred(A[0], B[0], C[0]);
                py = mid_pred(A[1], B[1], C[1]);
            }
        } else if (s->mb_x) { // predictor C is not out of bounds
            px = C[0];
            py = C[1];
        } else {
            px = py = 0;
        }
        /* Pullback MV as specified in 8.3.5.3.4 */
        {
            int qx, qy, X, Y;
            if (v->profile < PROFILE_ADVANCED) {
                qx = (s->mb_x << 5);
                qy = (s->mb_y << 5);
                X  = (s->mb_width  << 5) - 4;
                Y  = (s->mb_height << 5) - 4;
                if (qx + px < -28) px = -28 - qx;
                if (qy + py < -28) py = -28 - qy;
                if (qx + px > X) px = X - qx;
                if (qy + py > Y) py = Y - qy;
            } else {
                qx = (s->mb_x << 6);
                qy = (s->mb_y << 6);
                X  = (s->mb_width  << 6) - 4;
                Y  = (s->mb_height << 6) - 4;
                if (qx + px < -60) px = -60 - qx;
                if (qy + py < -60) py = -60 - qy;
                if (qx + px > X) px = X - qx;
                if (qy + py > Y) py = Y - qy;
            }
        }
        /* Calculate hybrid prediction as specified in 8.3.5.3.5 */
        if (0 && !s->first_slice_line && s->mb_x) {
            if (is_intra[xy - wrap])
                sum = FFABS(px) + FFABS(py);
            else
                sum = FFABS(px - A[0]) + FFABS(py - A[1]);
            if (sum > 32) {
                if (get_bits1(&s->gb)) {
                    px = A[0];
                    py = A[1];
                } else {
                    px = C[0];
                    py = C[1];
                }
            } else {
                if (is_intra[xy - 2])
                    sum = FFABS(px) + FFABS(py);
                else
                    sum = FFABS(px - C[0]) + FFABS(py - C[1]);
                if (sum > 32) {
                    if (get_bits1(&s->gb)) {
                        px = A[0];
                        py = A[1];
                    } else {
                        px = C[0];
                        py = C[1];
                    }
                }
            }
        }
        /* store MV using signed modulus of MV range defined in 4.11 */

        s->mv[1][0][0] = ((px + dmv_x[1] + r_x) & ((r_x << 1) - 1)) - r_x;
        s->mv[1][0][1] = ((py + dmv_y[1] + r_y) & ((r_y << 1) - 1)) - r_y;
    }
    s->current_picture.motion_val[0][xy][0] = s->mv[0][0][0];
    s->current_picture.motion_val[0][xy][1] = s->mv[0][0][1];
    s->current_picture.motion_val[1][xy][0] = s->mv[1][0][0];
    s->current_picture.motion_val[1][xy][1] = s->mv[1][0][1];
}

static inline void vc1_pred_b_mv_intfi(VC1Context *v, int n, int *dmv_x, int *dmv_y, int mv1, int *pred_flag)
{
    int dir = (v->bmvtype == BMV_TYPE_BACKWARD) ? 1 : 0;
    MpegEncContext *s = &v->s;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;

    if (v->bmvtype == BMV_TYPE_DIRECT) {
        int total_opp, k, f;
        if (s->next_picture.mb_type[mb_pos + v->mb_off] != MB_TYPE_INTRA) {
            s->mv[0][0][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][0],
                                      v->bfraction, 0, s->quarter_sample);
            s->mv[0][0][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][1],
                                      v->bfraction, 0, s->quarter_sample);
            s->mv[1][0][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][0],
                                      v->bfraction, 1, s->quarter_sample);
            s->mv[1][0][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][1],
                                      v->bfraction, 1, s->quarter_sample);

            total_opp = v->mv_f_next[0][s->block_index[0] + v->blocks_off]
                      + v->mv_f_next[0][s->block_index[1] + v->blocks_off]
                      + v->mv_f_next[0][s->block_index[2] + v->blocks_off]
                      + v->mv_f_next[0][s->block_index[3] + v->blocks_off];
            f = (total_opp > 2) ? 1 : 0;
        } else {
            s->mv[0][0][0] = s->mv[0][0][1] = 0;
            s->mv[1][0][0] = s->mv[1][0][1] = 0;
            f = 0;
        }
        v->ref_field_type[0] = v->ref_field_type[1] = v->cur_field_type ^ f;
        for (k = 0; k < 4; k++) {
            s->current_picture.motion_val[0][s->block_index[k] + v->blocks_off][0] = s->mv[0][0][0];
            s->current_picture.motion_val[0][s->block_index[k] + v->blocks_off][1] = s->mv[0][0][1];
            s->current_picture.motion_val[1][s->block_index[k] + v->blocks_off][0] = s->mv[1][0][0];
            s->current_picture.motion_val[1][s->block_index[k] + v->blocks_off][1] = s->mv[1][0][1];
            v->mv_f[0][s->block_index[k] + v->blocks_off] = f;
            v->mv_f[1][s->block_index[k] + v->blocks_off] = f;
        }
        return;
    }
    if (v->bmvtype == BMV_TYPE_INTERPOLATED) {
        vc1_pred_mv(v, 0, dmv_x[0], dmv_y[0],   1, v->range_x, v->range_y, v->mb_type[0], pred_flag[0], 0);
        vc1_pred_mv(v, 0, dmv_x[1], dmv_y[1],   1, v->range_x, v->range_y, v->mb_type[0], pred_flag[1], 1);
        return;
    }
    if (dir) { // backward
        vc1_pred_mv(v, n, dmv_x[1], dmv_y[1], mv1, v->range_x, v->range_y, v->mb_type[0], pred_flag[1], 1);
        if (n == 3 || mv1) {
            vc1_pred_mv(v, 0, dmv_x[0], dmv_y[0],   1, v->range_x, v->range_y, v->mb_type[0], 0, 0);
        }
    } else { // forward
        vc1_pred_mv(v, n, dmv_x[0], dmv_y[0], mv1, v->range_x, v->range_y, v->mb_type[0], pred_flag[0], 0);
        if (n == 3 || mv1) {
            vc1_pred_mv(v, 0, dmv_x[1], dmv_y[1],   1, v->range_x, v->range_y, v->mb_type[0], 0, 1);
        }
    }
}

/** Get predicted DC value for I-frames only
 * prediction dir: left=0, top=1
 * @param s MpegEncContext
 * @param overlap flag indicating that overlap filtering is used
 * @param pq integer part of picture quantizer
 * @param[in] n block index in the current MB
 * @param dc_val_ptr Pointer to DC predictor
 * @param dir_ptr Prediction direction for use in AC prediction
 */
static inline int vc1_i_pred_dc(MpegEncContext *s, int overlap, int pq, int n,
                                int16_t **dc_val_ptr, int *dir_ptr)
{
    int a, b, c, wrap, pred, scale;
    int16_t *dc_val;
    static const uint16_t dcpred[32] = {
        -1, 1024,  512,  341,  256,  205,  171,  146,  128,
             114,  102,   93,   85,   79,   73,   68,   64,
              60,   57,   54,   51,   49,   47,   45,   43,
              41,   39,   38,   37,   35,   34,   33
    };

    /* find prediction - wmv3_dc_scale always used here in fact */
    if (n < 4) scale = s->y_dc_scale;
    else       scale = s->c_dc_scale;

    wrap   = s->block_wrap[n];
    dc_val = s->dc_val[0] + s->block_index[n];

    /* B A
     * C X
     */
    c = dc_val[ - 1];
    b = dc_val[ - 1 - wrap];
    a = dc_val[ - wrap];

    if (pq < 9 || !overlap) {
        /* Set outer values */
        if (s->first_slice_line && (n != 2 && n != 3))
            b = a = dcpred[scale];
        if (s->mb_x == 0 && (n != 1 && n != 3))
            b = c = dcpred[scale];
    } else {
        /* Set outer values */
        if (s->first_slice_line && (n != 2 && n != 3))
            b = a = 0;
        if (s->mb_x == 0 && (n != 1 && n != 3))
            b = c = 0;
    }

    if (abs(a - b) <= abs(b - c)) {
        pred     = c;
        *dir_ptr = 1; // left
    } else {
        pred     = a;
        *dir_ptr = 0; // top
    }

    /* update predictor */
    *dc_val_ptr = &dc_val[0];
    return pred;
}


/** Get predicted DC value
 * prediction dir: left=0, top=1
 * @param s MpegEncContext
 * @param overlap flag indicating that overlap filtering is used
 * @param pq integer part of picture quantizer
 * @param[in] n block index in the current MB
 * @param a_avail flag indicating top block availability
 * @param c_avail flag indicating left block availability
 * @param dc_val_ptr Pointer to DC predictor
 * @param dir_ptr Prediction direction for use in AC prediction
 */
static inline int vc1_pred_dc(MpegEncContext *s, int overlap, int pq, int n,
                              int a_avail, int c_avail,
                              int16_t **dc_val_ptr, int *dir_ptr)
{
    int a, b, c, wrap, pred;
    int16_t *dc_val;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int q1, q2 = 0;
    int dqscale_index;

    wrap = s->block_wrap[n];
    dc_val = s->dc_val[0] + s->block_index[n];

    /* B A
     * C X
     */
    c = dc_val[ - 1];
    b = dc_val[ - 1 - wrap];
    a = dc_val[ - wrap];
    /* scale predictors if needed */
    q1 = s->current_picture.qscale_table[mb_pos];
    dqscale_index = s->y_dc_scale_table[q1] - 1;
    if (dqscale_index < 0)
        return 0;
    if (c_avail && (n != 1 && n != 3)) {
        q2 = s->current_picture.qscale_table[mb_pos - 1];
        if (q2 && q2 != q1)
            c = (c * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
    }
    if (a_avail && (n != 2 && n != 3)) {
        q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
        if (q2 && q2 != q1)
            a = (a * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
    }
    if (a_avail && c_avail && (n != 3)) {
        int off = mb_pos;
        if (n != 1)
            off--;
        if (n != 2)
            off -= s->mb_stride;
        q2 = s->current_picture.qscale_table[off];
        if (q2 && q2 != q1)
            b = (b * s->y_dc_scale_table[q2] * ff_vc1_dqscale[dqscale_index] + 0x20000) >> 18;
    }

    if (a_avail && c_avail) {
        if (abs(a - b) <= abs(b - c)) {
            pred     = c;
            *dir_ptr = 1; // left
        } else {
            pred     = a;
            *dir_ptr = 0; // top
        }
    } else if (a_avail) {
        pred     = a;
        *dir_ptr = 0; // top
    } else if (c_avail) {
        pred     = c;
        *dir_ptr = 1; // left
    } else {
        pred     = 0;
        *dir_ptr = 1; // left
    }

    /* update predictor */
    *dc_val_ptr = &dc_val[0];
    return pred;
}

/** @} */ // Block group

/**
 * @name VC1 Macroblock-level functions in Simple/Main Profiles
 * @see 7.1.4, p91 and 8.1.1.7, p(1)04
 * @{
 */

static inline int vc1_coded_block_pred(MpegEncContext * s, int n,
                                       uint8_t **coded_block_ptr)
{
    int xy, wrap, pred, a, b, c;

    xy   = s->block_index[n];
    wrap = s->b8_stride;

    /* B C
     * A X
     */
    a = s->coded_block[xy - 1       ];
    b = s->coded_block[xy - 1 - wrap];
    c = s->coded_block[xy     - wrap];

    if (b == c) {
        pred = a;
    } else {
        pred = c;
    }

    /* store value */
    *coded_block_ptr = &s->coded_block[xy];

    return pred;
}

/**
 * Decode one AC coefficient
 * @param v The VC1 context
 * @param last Last coefficient
 * @param skip How much zero coefficients to skip
 * @param value Decoded AC coefficient value
 * @param codingset set of VLC to decode data
 * @see 8.1.3.4
 */
static void vc1_decode_ac_coeff(VC1Context *v, int *last, int *skip,
                                int *value, int codingset)
{
    GetBitContext *gb = &v->s.gb;
    int index, escape, run = 0, level = 0, lst = 0;

    index = get_vlc2(gb, ff_vc1_ac_coeff_table[codingset].table, AC_VLC_BITS, 3);
    if (index != ff_vc1_ac_sizes[codingset] - 1) {
        run   = vc1_index_decode_table[codingset][index][0];
        level = vc1_index_decode_table[codingset][index][1];
        lst   = index >= vc1_last_decode_table[codingset] || get_bits_left(gb) < 0;
        if (get_bits1(gb))
            level = -level;
    } else {
        escape = decode210(gb);
        if (escape != 2) {
            index = get_vlc2(gb, ff_vc1_ac_coeff_table[codingset].table, AC_VLC_BITS, 3);
            run   = vc1_index_decode_table[codingset][index][0];
            level = vc1_index_decode_table[codingset][index][1];
            lst   = index >= vc1_last_decode_table[codingset];
            if (escape == 0) {
                if (lst)
                    level += vc1_last_delta_level_table[codingset][run];
                else
                    level += vc1_delta_level_table[codingset][run];
            } else {
                if (lst)
                    run += vc1_last_delta_run_table[codingset][level] + 1;
                else
                    run += vc1_delta_run_table[codingset][level] + 1;
            }
            if (get_bits1(gb))
                level = -level;
        } else {
            int sign;
            lst = get_bits1(gb);
            if (v->s.esc3_level_length == 0) {
                if (v->pq < 8 || v->dquantfrm) { // table 59
                    v->s.esc3_level_length = get_bits(gb, 3);
                    if (!v->s.esc3_level_length)
                        v->s.esc3_level_length = get_bits(gb, 2) + 8;
                } else { // table 60
                    v->s.esc3_level_length = get_unary(gb, 1, 6) + 2;
                }
                v->s.esc3_run_length = 3 + get_bits(gb, 2);
            }
            run   = get_bits(gb, v->s.esc3_run_length);
            sign  = get_bits1(gb);
            level = get_bits(gb, v->s.esc3_level_length);
            if (sign)
                level = -level;
        }
    }

    *last  = lst;
    *skip  = run;
    *value = level;
}

/** Decode intra block in intra frames - should be faster than decode_intra_block
 * @param v VC1Context
 * @param block block to decode
 * @param[in] n subblock index
 * @param coded are AC coeffs present or not
 * @param codingset set of VLC to decode data
 */
static int vc1_decode_i_block(VC1Context *v, int16_t block[64], int n,
                              int coded, int codingset)
{
    GetBitContext *gb = &v->s.gb;
    MpegEncContext *s = &v->s;
    int dc_pred_dir = 0; /* Direction of the DC prediction used */
    int i;
    int16_t *dc_val;
    int16_t *ac_val, *ac_val2;
    int dcdiff;

    /* Get DC differential */
    if (n < 4) {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    } else {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    }
    if (dcdiff < 0) {
        av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
        return -1;
    }
    if (dcdiff) {
        if (dcdiff == 119 /* ESC index value */) {
            /* TODO: Optimize */
            if (v->pq == 1)      dcdiff = get_bits(gb, 10);
            else if (v->pq == 2) dcdiff = get_bits(gb, 9);
            else                 dcdiff = get_bits(gb, 8);
        } else {
            if (v->pq == 1)
                dcdiff = (dcdiff << 2) + get_bits(gb, 2) - 3;
            else if (v->pq == 2)
                dcdiff = (dcdiff << 1) + get_bits1(gb)   - 1;
        }
        if (get_bits1(gb))
            dcdiff = -dcdiff;
    }

    /* Prediction */
    dcdiff += vc1_i_pred_dc(&v->s, v->overlap, v->pq, n, &dc_val, &dc_pred_dir);
    *dc_val = dcdiff;

    /* Store the quantized DC coeff, used for prediction */
    if (n < 4) {
        block[0] = dcdiff * s->y_dc_scale;
    } else {
        block[0] = dcdiff * s->c_dc_scale;
    }
    /* Skip ? */
    if (!coded) {
        goto not_coded;
    }

    // AC Decoding
    i = 1;

    {
        int last = 0, skip, value;
        const uint8_t *zz_table;
        int scale;
        int k;

        scale = v->pq * 2 + v->halfpq;

        if (v->s.ac_pred) {
            if (!dc_pred_dir)
                zz_table = v->zz_8x8[2];
            else
                zz_table = v->zz_8x8[3];
        } else
            zz_table = v->zz_8x8[1];

        ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
        ac_val2 = ac_val;
        if (dc_pred_dir) // left
            ac_val -= 16;
        else // top
            ac_val -= 16 * s->block_wrap[n];

        while (!last) {
            vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
            i += skip;
            if (i > 63)
                break;
            block[zz_table[i++]] = value;
        }

        /* apply AC prediction if needed */
        if (s->ac_pred) {
            if (dc_pred_dir) { // left
                for (k = 1; k < 8; k++)
                    block[k << v->left_blk_sh] += ac_val[k];
            } else { // top
                for (k = 1; k < 8; k++)
                    block[k << v->top_blk_sh] += ac_val[k + 8];
            }
        }
        /* save AC coeffs for further prediction */
        for (k = 1; k < 8; k++) {
            ac_val2[k]     = block[k << v->left_blk_sh];
            ac_val2[k + 8] = block[k << v->top_blk_sh];
        }

        /* scale AC coeffs */
        for (k = 1; k < 64; k++)
            if (block[k]) {
                block[k] *= scale;
                if (!v->pquantizer)
                    block[k] += (block[k] < 0) ? -v->pq : v->pq;
            }

        if (s->ac_pred) i = 63;
    }

not_coded:
    if (!coded) {
        int k, scale;
        ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
        ac_val2 = ac_val;

        i = 0;
        scale = v->pq * 2 + v->halfpq;
        memset(ac_val2, 0, 16 * 2);
        if (dc_pred_dir) { // left
            ac_val -= 16;
            if (s->ac_pred)
                memcpy(ac_val2, ac_val, 8 * 2);
        } else { // top
            ac_val -= 16 * s->block_wrap[n];
            if (s->ac_pred)
                memcpy(ac_val2 + 8, ac_val + 8, 8 * 2);
        }

        /* apply AC prediction if needed */
        if (s->ac_pred) {
            if (dc_pred_dir) { //left
                for (k = 1; k < 8; k++) {
                    block[k << v->left_blk_sh] = ac_val[k] * scale;
                    if (!v->pquantizer && block[k << v->left_blk_sh])
                        block[k << v->left_blk_sh] += (block[k << v->left_blk_sh] < 0) ? -v->pq : v->pq;
                }
            } else { // top
                for (k = 1; k < 8; k++) {
                    block[k << v->top_blk_sh] = ac_val[k + 8] * scale;
                    if (!v->pquantizer && block[k << v->top_blk_sh])
                        block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -v->pq : v->pq;
                }
            }
            i = 63;
        }
    }
    s->block_last_index[n] = i;

    return 0;
}

/** Decode intra block in intra frames - should be faster than decode_intra_block
 * @param v VC1Context
 * @param block block to decode
 * @param[in] n subblock number
 * @param coded are AC coeffs present or not
 * @param codingset set of VLC to decode data
 * @param mquant quantizer value for this macroblock
 */
static int vc1_decode_i_block_adv(VC1Context *v, int16_t block[64], int n,
                                  int coded, int codingset, int mquant)
{
    GetBitContext *gb = &v->s.gb;
    MpegEncContext *s = &v->s;
    int dc_pred_dir = 0; /* Direction of the DC prediction used */
    int i;
    int16_t *dc_val = NULL;
    int16_t *ac_val, *ac_val2;
    int dcdiff;
    int a_avail = v->a_avail, c_avail = v->c_avail;
    int use_pred = s->ac_pred;
    int scale;
    int q1, q2 = 0;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;

    /* Get DC differential */
    if (n < 4) {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    } else {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    }
    if (dcdiff < 0) {
        av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
        return -1;
    }
    if (dcdiff) {
        if (dcdiff == 119 /* ESC index value */) {
            /* TODO: Optimize */
            if (mquant == 1)      dcdiff = get_bits(gb, 10);
            else if (mquant == 2) dcdiff = get_bits(gb, 9);
            else                  dcdiff = get_bits(gb, 8);
        } else {
            if (mquant == 1)
                dcdiff = (dcdiff << 2) + get_bits(gb, 2) - 3;
            else if (mquant == 2)
                dcdiff = (dcdiff << 1) + get_bits1(gb)   - 1;
        }
        if (get_bits1(gb))
            dcdiff = -dcdiff;
    }

    /* Prediction */
    dcdiff += vc1_pred_dc(&v->s, v->overlap, mquant, n, v->a_avail, v->c_avail, &dc_val, &dc_pred_dir);
    *dc_val = dcdiff;

    /* Store the quantized DC coeff, used for prediction */
    if (n < 4) {
        block[0] = dcdiff * s->y_dc_scale;
    } else {
        block[0] = dcdiff * s->c_dc_scale;
    }

    //AC Decoding
    i = 1;

    /* check if AC is needed at all */
    if (!a_avail && !c_avail)
        use_pred = 0;
    ac_val  = s->ac_val[0][0] + s->block_index[n] * 16;
    ac_val2 = ac_val;

    scale = mquant * 2 + ((mquant == v->pq) ? v->halfpq : 0);

    if (dc_pred_dir) // left
        ac_val -= 16;
    else // top
        ac_val -= 16 * s->block_wrap[n];

    q1 = s->current_picture.qscale_table[mb_pos];
    if ( dc_pred_dir && c_avail && mb_pos)
        q2 = s->current_picture.qscale_table[mb_pos - 1];
    if (!dc_pred_dir && a_avail && mb_pos >= s->mb_stride)
        q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
    if ( dc_pred_dir && n == 1)
        q2 = q1;
    if (!dc_pred_dir && n == 2)
        q2 = q1;
    if (n == 3)
        q2 = q1;

    if (coded) {
        int last = 0, skip, value;
        const uint8_t *zz_table;
        int k;

        if (v->s.ac_pred) {
            if (!use_pred && v->fcm == ILACE_FRAME) {
                zz_table = v->zzi_8x8;
            } else {
                if (!dc_pred_dir) // top
                    zz_table = v->zz_8x8[2];
                else // left
                    zz_table = v->zz_8x8[3];
            }
        } else {
            if (v->fcm != ILACE_FRAME)
                zz_table = v->zz_8x8[1];
            else
                zz_table = v->zzi_8x8;
        }

        while (!last) {
            vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
            i += skip;
            if (i > 63)
                break;
            block[zz_table[i++]] = value;
        }

        /* apply AC prediction if needed */
        if (use_pred) {
            /* scale predictors if needed*/
            if (q2 && q1 != q2) {
                q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;

                if (q1 < 1)
                    return AVERROR_INVALIDDATA;
                if (dc_pred_dir) { // left
                    for (k = 1; k < 8; k++)
                        block[k << v->left_blk_sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                } else { // top
                    for (k = 1; k < 8; k++)
                        block[k << v->top_blk_sh] += (ac_val[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            } else {
                if (dc_pred_dir) { //left
                    for (k = 1; k < 8; k++)
                        block[k << v->left_blk_sh] += ac_val[k];
                } else { //top
                    for (k = 1; k < 8; k++)
                        block[k << v->top_blk_sh] += ac_val[k + 8];
                }
            }
        }
        /* save AC coeffs for further prediction */
        for (k = 1; k < 8; k++) {
            ac_val2[k    ] = block[k << v->left_blk_sh];
            ac_val2[k + 8] = block[k << v->top_blk_sh];
        }

        /* scale AC coeffs */
        for (k = 1; k < 64; k++)
            if (block[k]) {
                block[k] *= scale;
                if (!v->pquantizer)
                    block[k] += (block[k] < 0) ? -mquant : mquant;
            }

        if (use_pred) i = 63;
    } else { // no AC coeffs
        int k;

        memset(ac_val2, 0, 16 * 2);
        if (dc_pred_dir) { // left
            if (use_pred) {
                memcpy(ac_val2, ac_val, 8 * 2);
                if (q2 && q1 != q2) {
                    q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                    q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                    if (q1 < 1)
                        return AVERROR_INVALIDDATA;
                    for (k = 1; k < 8; k++)
                        ac_val2[k] = (ac_val2[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            }
        } else { // top
            if (use_pred) {
                memcpy(ac_val2 + 8, ac_val + 8, 8 * 2);
                if (q2 && q1 != q2) {
                    q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                    q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                    if (q1 < 1)
                        return AVERROR_INVALIDDATA;
                    for (k = 1; k < 8; k++)
                        ac_val2[k + 8] = (ac_val2[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            }
        }

        /* apply AC prediction if needed */
        if (use_pred) {
            if (dc_pred_dir) { // left
                for (k = 1; k < 8; k++) {
                    block[k << v->left_blk_sh] = ac_val2[k] * scale;
                    if (!v->pquantizer && block[k << v->left_blk_sh])
                        block[k << v->left_blk_sh] += (block[k << v->left_blk_sh] < 0) ? -mquant : mquant;
                }
            } else { // top
                for (k = 1; k < 8; k++) {
                    block[k << v->top_blk_sh] = ac_val2[k + 8] * scale;
                    if (!v->pquantizer && block[k << v->top_blk_sh])
                        block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -mquant : mquant;
                }
            }
            i = 63;
        }
    }
    s->block_last_index[n] = i;

    return 0;
}

/** Decode intra block in inter frames - more generic version than vc1_decode_i_block
 * @param v VC1Context
 * @param block block to decode
 * @param[in] n subblock index
 * @param coded are AC coeffs present or not
 * @param mquant block quantizer
 * @param codingset set of VLC to decode data
 */
static int vc1_decode_intra_block(VC1Context *v, int16_t block[64], int n,
                                  int coded, int mquant, int codingset)
{
    GetBitContext *gb = &v->s.gb;
    MpegEncContext *s = &v->s;
    int dc_pred_dir = 0; /* Direction of the DC prediction used */
    int i;
    int16_t *dc_val = NULL;
    int16_t *ac_val, *ac_val2;
    int dcdiff;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int a_avail = v->a_avail, c_avail = v->c_avail;
    int use_pred = s->ac_pred;
    int scale;
    int q1, q2 = 0;

    s->dsp.clear_block(block);

    /* XXX: Guard against dumb values of mquant */
    mquant = (mquant < 1) ? 0 : ((mquant > 31) ? 31 : mquant);

    /* Set DC scale - y and c use the same */
    s->y_dc_scale = s->y_dc_scale_table[mquant];
    s->c_dc_scale = s->c_dc_scale_table[mquant];

    /* Get DC differential */
    if (n < 4) {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_luma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    } else {
        dcdiff = get_vlc2(&s->gb, ff_msmp4_dc_chroma_vlc[s->dc_table_index].table, DC_VLC_BITS, 3);
    }
    if (dcdiff < 0) {
        av_log(s->avctx, AV_LOG_ERROR, "Illegal DC VLC\n");
        return -1;
    }
    if (dcdiff) {
        if (dcdiff == 119 /* ESC index value */) {
            /* TODO: Optimize */
            if (mquant == 1)      dcdiff = get_bits(gb, 10);
            else if (mquant == 2) dcdiff = get_bits(gb, 9);
            else                  dcdiff = get_bits(gb, 8);
        } else {
            if (mquant == 1)
                dcdiff = (dcdiff << 2) + get_bits(gb, 2) - 3;
            else if (mquant == 2)
                dcdiff = (dcdiff << 1) + get_bits1(gb)   - 1;
        }
        if (get_bits1(gb))
            dcdiff = -dcdiff;
    }

    /* Prediction */
    dcdiff += vc1_pred_dc(&v->s, v->overlap, mquant, n, a_avail, c_avail, &dc_val, &dc_pred_dir);
    *dc_val = dcdiff;

    /* Store the quantized DC coeff, used for prediction */

    if (n < 4) {
        block[0] = dcdiff * s->y_dc_scale;
    } else {
        block[0] = dcdiff * s->c_dc_scale;
    }

    //AC Decoding
    i = 1;

    /* check if AC is needed at all and adjust direction if needed */
    if (!a_avail) dc_pred_dir = 1;
    if (!c_avail) dc_pred_dir = 0;
    if (!a_avail && !c_avail) use_pred = 0;
    ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
    ac_val2 = ac_val;

    scale = mquant * 2 + v->halfpq;

    if (dc_pred_dir) //left
        ac_val -= 16;
    else //top
        ac_val -= 16 * s->block_wrap[n];

    q1 = s->current_picture.qscale_table[mb_pos];
    if (dc_pred_dir && c_avail && mb_pos)
        q2 = s->current_picture.qscale_table[mb_pos - 1];
    if (!dc_pred_dir && a_avail && mb_pos >= s->mb_stride)
        q2 = s->current_picture.qscale_table[mb_pos - s->mb_stride];
    if ( dc_pred_dir && n == 1)
        q2 = q1;
    if (!dc_pred_dir && n == 2)
        q2 = q1;
    if (n == 3) q2 = q1;

    if (coded) {
        int last = 0, skip, value;
        int k;

        while (!last) {
            vc1_decode_ac_coeff(v, &last, &skip, &value, codingset);
            i += skip;
            if (i > 63)
                break;
            if (v->fcm == PROGRESSIVE)
                block[v->zz_8x8[0][i++]] = value;
            else {
                if (use_pred && (v->fcm == ILACE_FRAME)) {
                    if (!dc_pred_dir) // top
                        block[v->zz_8x8[2][i++]] = value;
                    else // left
                        block[v->zz_8x8[3][i++]] = value;
                } else {
                    block[v->zzi_8x8[i++]] = value;
                }
            }
        }

        /* apply AC prediction if needed */
        if (use_pred) {
            /* scale predictors if needed*/
            if (q2 && q1 != q2) {
                q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;

                if (q1 < 1)
                    return AVERROR_INVALIDDATA;
                if (dc_pred_dir) { // left
                    for (k = 1; k < 8; k++)
                        block[k << v->left_blk_sh] += (ac_val[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                } else { //top
                    for (k = 1; k < 8; k++)
                        block[k << v->top_blk_sh] += (ac_val[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            } else {
                if (dc_pred_dir) { // left
                    for (k = 1; k < 8; k++)
                        block[k << v->left_blk_sh] += ac_val[k];
                } else { // top
                    for (k = 1; k < 8; k++)
                        block[k << v->top_blk_sh] += ac_val[k + 8];
                }
            }
        }
        /* save AC coeffs for further prediction */
        for (k = 1; k < 8; k++) {
            ac_val2[k    ] = block[k << v->left_blk_sh];
            ac_val2[k + 8] = block[k << v->top_blk_sh];
        }

        /* scale AC coeffs */
        for (k = 1; k < 64; k++)
            if (block[k]) {
                block[k] *= scale;
                if (!v->pquantizer)
                    block[k] += (block[k] < 0) ? -mquant : mquant;
            }

        if (use_pred) i = 63;
    } else { // no AC coeffs
        int k;

        memset(ac_val2, 0, 16 * 2);
        if (dc_pred_dir) { // left
            if (use_pred) {
                memcpy(ac_val2, ac_val, 8 * 2);
                if (q2 && q1 != q2) {
                    q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                    q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                    if (q1 < 1)
                        return AVERROR_INVALIDDATA;
                    for (k = 1; k < 8; k++)
                        ac_val2[k] = (ac_val2[k] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            }
        } else { // top
            if (use_pred) {
                memcpy(ac_val2 + 8, ac_val + 8, 8 * 2);
                if (q2 && q1 != q2) {
                    q1 = q1 * 2 + ((q1 == v->pq) ? v->halfpq : 0) - 1;
                    q2 = q2 * 2 + ((q2 == v->pq) ? v->halfpq : 0) - 1;
                    if (q1 < 1)
                        return AVERROR_INVALIDDATA;
                    for (k = 1; k < 8; k++)
                        ac_val2[k + 8] = (ac_val2[k + 8] * q2 * ff_vc1_dqscale[q1 - 1] + 0x20000) >> 18;
                }
            }
        }

        /* apply AC prediction if needed */
        if (use_pred) {
            if (dc_pred_dir) { // left
                for (k = 1; k < 8; k++) {
                    block[k << v->left_blk_sh] = ac_val2[k] * scale;
                    if (!v->pquantizer && block[k << v->left_blk_sh])
                        block[k << v->left_blk_sh] += (block[k << v->left_blk_sh] < 0) ? -mquant : mquant;
                }
            } else { // top
                for (k = 1; k < 8; k++) {
                    block[k << v->top_blk_sh] = ac_val2[k + 8] * scale;
                    if (!v->pquantizer && block[k << v->top_blk_sh])
                        block[k << v->top_blk_sh] += (block[k << v->top_blk_sh] < 0) ? -mquant : mquant;
                }
            }
            i = 63;
        }
    }
    s->block_last_index[n] = i;

    return 0;
}

/** Decode P block
 */
static int vc1_decode_p_block(VC1Context *v, int16_t block[64], int n,
                              int mquant, int ttmb, int first_block,
                              uint8_t *dst, int linesize, int skip_block,
                              int *ttmb_out)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i, j;
    int subblkpat = 0;
    int scale, off, idx, last, skip, value;
    int ttblk = ttmb & 7;
    int pat = 0;

    s->dsp.clear_block(block);

    if (ttmb == -1) {
        ttblk = ff_vc1_ttblk_to_tt[v->tt_index][get_vlc2(gb, ff_vc1_ttblk_vlc[v->tt_index].table, VC1_TTBLK_VLC_BITS, 1)];
    }
    if (ttblk == TT_4X4) {
        subblkpat = ~(get_vlc2(gb, ff_vc1_subblkpat_vlc[v->tt_index].table, VC1_SUBBLKPAT_VLC_BITS, 1) + 1);
    }
    if ((ttblk != TT_8X8 && ttblk != TT_4X4)
        && ((v->ttmbf || (ttmb != -1 && (ttmb & 8) && !first_block))
            || (!v->res_rtm_flag && !first_block))) {
        subblkpat = decode012(gb);
        if (subblkpat)
            subblkpat ^= 3; // swap decoded pattern bits
        if (ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM)
            ttblk = TT_8X4;
        if (ttblk == TT_4X8_RIGHT || ttblk == TT_4X8_LEFT)
            ttblk = TT_4X8;
    }
    scale = 2 * mquant + ((v->pq == mquant) ? v->halfpq : 0);

    // convert transforms like 8X4_TOP to generic TT and SUBBLKPAT
    if (ttblk == TT_8X4_TOP || ttblk == TT_8X4_BOTTOM) {
        subblkpat = 2 - (ttblk == TT_8X4_TOP);
        ttblk     = TT_8X4;
    }
    if (ttblk == TT_4X8_RIGHT || ttblk == TT_4X8_LEFT) {
        subblkpat = 2 - (ttblk == TT_4X8_LEFT);
        ttblk     = TT_4X8;
    }
    switch (ttblk) {
    case TT_8X8:
        pat  = 0xF;
        i    = 0;
        last = 0;
        while (!last) {
            vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
            i += skip;
            if (i > 63)
                break;
            if (!v->fcm)
                idx = v->zz_8x8[0][i++];
            else
                idx = v->zzi_8x8[i++];
            block[idx] = value * scale;
            if (!v->pquantizer)
                block[idx] += (block[idx] < 0) ? -mquant : mquant;
        }
        if (!skip_block) {
            if (i == 1)
                v->vc1dsp.vc1_inv_trans_8x8_dc(dst, linesize, block);
            else {
                v->vc1dsp.vc1_inv_trans_8x8(block);
                s->dsp.add_pixels_clamped(block, dst, linesize);
            }
        }
        break;
    case TT_4X4:
        pat = ~subblkpat & 0xF;
        for (j = 0; j < 4; j++) {
            last = subblkpat & (1 << (3 - j));
            i    = 0;
            off  = (j & 1) * 4 + (j & 2) * 16;
            while (!last) {
                vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                i += skip;
                if (i > 15)
                    break;
                if (!v->fcm)
                    idx = ff_vc1_simple_progressive_4x4_zz[i++];
                else
                    idx = ff_vc1_adv_interlaced_4x4_zz[i++];
                block[idx + off] = value * scale;
                if (!v->pquantizer)
                    block[idx + off] += (block[idx + off] < 0) ? -mquant : mquant;
            }
            if (!(subblkpat & (1 << (3 - j))) && !skip_block) {
                if (i == 1)
                    v->vc1dsp.vc1_inv_trans_4x4_dc(dst + (j & 1) * 4 + (j & 2) * 2 * linesize, linesize, block + off);
                else
                    v->vc1dsp.vc1_inv_trans_4x4(dst + (j & 1) * 4 + (j & 2) *  2 * linesize, linesize, block + off);
            }
        }
        break;
    case TT_8X4:
        pat = ~((subblkpat & 2) * 6 + (subblkpat & 1) * 3) & 0xF;
        for (j = 0; j < 2; j++) {
            last = subblkpat & (1 << (1 - j));
            i    = 0;
            off  = j * 32;
            while (!last) {
                vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                i += skip;
                if (i > 31)
                    break;
                if (!v->fcm)
                    idx = v->zz_8x4[i++] + off;
                else
                    idx = ff_vc1_adv_interlaced_8x4_zz[i++] + off;
                block[idx] = value * scale;
                if (!v->pquantizer)
                    block[idx] += (block[idx] < 0) ? -mquant : mquant;
            }
            if (!(subblkpat & (1 << (1 - j))) && !skip_block) {
                if (i == 1)
                    v->vc1dsp.vc1_inv_trans_8x4_dc(dst + j * 4 * linesize, linesize, block + off);
                else
                    v->vc1dsp.vc1_inv_trans_8x4(dst + j * 4 * linesize, linesize, block + off);
            }
        }
        break;
    case TT_4X8:
        pat = ~(subblkpat * 5) & 0xF;
        for (j = 0; j < 2; j++) {
            last = subblkpat & (1 << (1 - j));
            i    = 0;
            off  = j * 4;
            while (!last) {
                vc1_decode_ac_coeff(v, &last, &skip, &value, v->codingset2);
                i += skip;
                if (i > 31)
                    break;
                if (!v->fcm)
                    idx = v->zz_4x8[i++] + off;
                else
                    idx = ff_vc1_adv_interlaced_4x8_zz[i++] + off;
                block[idx] = value * scale;
                if (!v->pquantizer)
                    block[idx] += (block[idx] < 0) ? -mquant : mquant;
            }
            if (!(subblkpat & (1 << (1 - j))) && !skip_block) {
                if (i == 1)
                    v->vc1dsp.vc1_inv_trans_4x8_dc(dst + j * 4, linesize, block + off);
                else
                    v->vc1dsp.vc1_inv_trans_4x8(dst + j*4, linesize, block + off);
            }
        }
        break;
    }
    if (ttmb_out)
        *ttmb_out |= ttblk << (n * 4);
    return pat;
}

/** @} */ // Macroblock group

static const int size_table  [6] = { 0, 2, 3, 4,  5,  8 };
static const int offset_table[6] = { 0, 1, 3, 7, 15, 31 };

static av_always_inline void vc1_apply_p_v_loop_filter(VC1Context *v, int block_num)
{
    MpegEncContext *s  = &v->s;
    int mb_cbp         = v->cbp[s->mb_x - s->mb_stride],
        block_cbp      = mb_cbp      >> (block_num * 4), bottom_cbp,
        mb_is_intra    = v->is_intra[s->mb_x - s->mb_stride],
        block_is_intra = mb_is_intra >> (block_num * 4), bottom_is_intra;
    int idx, linesize  = block_num > 3 ? s->uvlinesize : s->linesize, ttblk;
    uint8_t *dst;

    if (block_num > 3) {
        dst      = s->dest[block_num - 3];
    } else {
        dst      = s->dest[0] + (block_num & 1) * 8 + ((block_num & 2) * 4 - 8) * linesize;
    }
    if (s->mb_y != s->end_mb_y || block_num < 2) {
        int16_t (*mv)[2];
        int mv_stride;

        if (block_num > 3) {
            bottom_cbp      = v->cbp[s->mb_x]      >> (block_num * 4);
            bottom_is_intra = v->is_intra[s->mb_x] >> (block_num * 4);
            mv              = &v->luma_mv[s->mb_x - s->mb_stride];
            mv_stride       = s->mb_stride;
        } else {
            bottom_cbp      = (block_num < 2) ? (mb_cbp               >> ((block_num + 2) * 4))
                                              : (v->cbp[s->mb_x]      >> ((block_num - 2) * 4));
            bottom_is_intra = (block_num < 2) ? (mb_is_intra          >> ((block_num + 2) * 4))
                                              : (v->is_intra[s->mb_x] >> ((block_num - 2) * 4));
            mv_stride       = s->b8_stride;
            mv              = &s->current_picture.motion_val[0][s->block_index[block_num] - 2 * mv_stride];
        }

        if (bottom_is_intra & 1 || block_is_intra & 1 ||
            mv[0][0] != mv[mv_stride][0] || mv[0][1] != mv[mv_stride][1]) {
            v->vc1dsp.vc1_v_loop_filter8(dst, linesize, v->pq);
        } else {
            idx = ((bottom_cbp >> 2) | block_cbp) & 3;
            if (idx == 3) {
                v->vc1dsp.vc1_v_loop_filter8(dst, linesize, v->pq);
            } else if (idx) {
                if (idx == 1)
                    v->vc1dsp.vc1_v_loop_filter4(dst + 4, linesize, v->pq);
                else
                    v->vc1dsp.vc1_v_loop_filter4(dst,     linesize, v->pq);
            }
        }
    }

    dst -= 4 * linesize;
    ttblk = (v->ttblk[s->mb_x - s->mb_stride] >> (block_num * 4)) & 0xF;
    if (ttblk == TT_4X4 || ttblk == TT_8X4) {
        idx = (block_cbp | (block_cbp >> 2)) & 3;
        if (idx == 3) {
            v->vc1dsp.vc1_v_loop_filter8(dst, linesize, v->pq);
        } else if (idx) {
            if (idx == 1)
                v->vc1dsp.vc1_v_loop_filter4(dst + 4, linesize, v->pq);
            else
                v->vc1dsp.vc1_v_loop_filter4(dst,     linesize, v->pq);
        }
    }
}

static av_always_inline void vc1_apply_p_h_loop_filter(VC1Context *v, int block_num)
{
    MpegEncContext *s  = &v->s;
    int mb_cbp         = v->cbp[s->mb_x - 1 - s->mb_stride],
        block_cbp      = mb_cbp      >> (block_num * 4), right_cbp,
        mb_is_intra    = v->is_intra[s->mb_x - 1 - s->mb_stride],
        block_is_intra = mb_is_intra >> (block_num * 4), right_is_intra;
    int idx, linesize  = block_num > 3 ? s->uvlinesize : s->linesize, ttblk;
    uint8_t *dst;

    if (block_num > 3) {
        dst = s->dest[block_num - 3] - 8 * linesize;
    } else {
        dst = s->dest[0] + (block_num & 1) * 8 + ((block_num & 2) * 4 - 16) * linesize - 8;
    }

    if (s->mb_x != s->mb_width || !(block_num & 5)) {
        int16_t (*mv)[2];

        if (block_num > 3) {
            right_cbp      = v->cbp[s->mb_x - s->mb_stride] >> (block_num * 4);
            right_is_intra = v->is_intra[s->mb_x - s->mb_stride] >> (block_num * 4);
            mv             = &v->luma_mv[s->mb_x - s->mb_stride - 1];
        } else {
            right_cbp      = (block_num & 1) ? (v->cbp[s->mb_x - s->mb_stride]      >> ((block_num - 1) * 4))
                                             : (mb_cbp                              >> ((block_num + 1) * 4));
            right_is_intra = (block_num & 1) ? (v->is_intra[s->mb_x - s->mb_stride] >> ((block_num - 1) * 4))
                                             : (mb_is_intra                         >> ((block_num + 1) * 4));
            mv             = &s->current_picture.motion_val[0][s->block_index[block_num] - s->b8_stride * 2 - 2];
        }
        if (block_is_intra & 1 || right_is_intra & 1 || mv[0][0] != mv[1][0] || mv[0][1] != mv[1][1]) {
            v->vc1dsp.vc1_h_loop_filter8(dst, linesize, v->pq);
        } else {
            idx = ((right_cbp >> 1) | block_cbp) & 5; // FIXME check
            if (idx == 5) {
                v->vc1dsp.vc1_h_loop_filter8(dst, linesize, v->pq);
            } else if (idx) {
                if (idx == 1)
                    v->vc1dsp.vc1_h_loop_filter4(dst + 4 * linesize, linesize, v->pq);
                else
                    v->vc1dsp.vc1_h_loop_filter4(dst,                linesize, v->pq);
            }
        }
    }

    dst -= 4;
    ttblk = (v->ttblk[s->mb_x - s->mb_stride - 1] >> (block_num * 4)) & 0xf;
    if (ttblk == TT_4X4 || ttblk == TT_4X8) {
        idx = (block_cbp | (block_cbp >> 1)) & 5;
        if (idx == 5) {
            v->vc1dsp.vc1_h_loop_filter8(dst, linesize, v->pq);
        } else if (idx) {
            if (idx == 1)
                v->vc1dsp.vc1_h_loop_filter4(dst + linesize * 4, linesize, v->pq);
            else
                v->vc1dsp.vc1_h_loop_filter4(dst,                linesize, v->pq);
        }
    }
}

static void vc1_apply_p_loop_filter(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int i;

    for (i = 0; i < 6; i++) {
        vc1_apply_p_v_loop_filter(v, i);
    }

    /* V always precedes H, therefore we run H one MB before V;
     * at the end of a row, we catch up to complete the row */
    if (s->mb_x) {
        for (i = 0; i < 6; i++) {
            vc1_apply_p_h_loop_filter(v, i);
        }
        if (s->mb_x == s->mb_width - 1) {
            s->mb_x++;
            ff_update_block_index(s);
            for (i = 0; i < 6; i++) {
                vc1_apply_p_h_loop_filter(v, i);
            }
        }
    }
}

/** Decode one P-frame MB
 */
static int vc1_decode_p_mb(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i, j;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */

    int mb_has_coeffs = 1; /* last_flag */
    int dmv_x, dmv_y; /* Differential MV components */
    int index, index1; /* LUT indexes */
    int val, sign; /* temp values */
    int first_block = 1;
    int dst_idx, off;
    int skipped, fourmv;
    int block_cbp = 0, pat, block_tt = 0, block_intra = 0;

    mquant = v->pq; /* lossy initialization */

    if (v->mv_type_is_raw)
        fourmv = get_bits1(gb);
    else
        fourmv = v->mv_type_mb_plane[mb_pos];
    if (v->skip_is_raw)
        skipped = get_bits1(gb);
    else
        skipped = v->s.mbskip_table[mb_pos];

    if (!fourmv) { /* 1MV mode */
        if (!skipped) {
            GET_MVDATA(dmv_x, dmv_y);

            if (s->mb_intra) {
                s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
                s->current_picture.motion_val[1][s->block_index[0]][1] = 0;
            }
            s->current_picture.mb_type[mb_pos] = s->mb_intra ? MB_TYPE_INTRA : MB_TYPE_16x16;
            vc1_pred_mv(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0, 0);

            /* FIXME Set DC val for inter block ? */
            if (s->mb_intra && !mb_has_coeffs) {
                GET_MQUANT();
                s->ac_pred = get_bits1(gb);
                cbp        = 0;
            } else if (mb_has_coeffs) {
                if (s->mb_intra)
                    s->ac_pred = get_bits1(gb);
                cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
                GET_MQUANT();
            } else {
                mquant = v->pq;
                cbp    = 0;
            }
            s->current_picture.qscale_table[mb_pos] = mquant;

            if (!v->ttmbf && !s->mb_intra && mb_has_coeffs)
                ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table,
                                VC1_TTMB_VLC_BITS, 2);
            if (!s->mb_intra) vc1_mc_1mv(v, 0);
            dst_idx = 0;
            for (i = 0; i < 6; i++) {
                s->dc_val[0][s->block_index[i]] = 0;
                dst_idx += i >> 2;
                val = ((cbp >> (5 - i)) & 1);
                off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                v->mb_type[0][s->block_index[i]] = s->mb_intra;
                if (s->mb_intra) {
                    /* check if prediction blocks A and C are available */
                    v->a_avail = v->c_avail = 0;
                    if (i == 2 || i == 3 || !s->first_slice_line)
                        v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                    if (i == 1 || i == 3 || s->mb_x)
                        v->c_avail = v->mb_type[0][s->block_index[i] - 1];

                    vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                           (i & 4) ? v->codingset2 : v->codingset);
                    if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                        continue;
                    v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                    if (v->rangeredfrm)
                        for (j = 0; j < 64; j++)
                            s->block[i][j] <<= 1;
                    s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                    if (v->pq >= 9 && v->overlap) {
                        if (v->c_avail)
                            v->vc1dsp.vc1_h_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                        if (v->a_avail)
                            v->vc1dsp.vc1_v_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                    }
                    block_cbp   |= 0xF << (i << 2);
                    block_intra |= 1 << i;
                } else if (val) {
                    pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb, first_block,
                                             s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize,
                                             (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                    block_cbp |= pat << (i << 2);
                    if (!v->ttmbf && ttmb < 8)
                        ttmb = -1;
                    first_block = 0;
                }
            }
        } else { // skipped
            s->mb_intra = 0;
            for (i = 0; i < 6; i++) {
                v->mb_type[0][s->block_index[i]] = 0;
                s->dc_val[0][s->block_index[i]]  = 0;
            }
            s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
            s->current_picture.qscale_table[mb_pos] = 0;
            vc1_pred_mv(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0, 0);
            vc1_mc_1mv(v, 0);
        }
    } else { // 4MV mode
        if (!skipped /* unskipped MB */) {
            int intra_count = 0, coded_inter = 0;
            int is_intra[6], is_coded[6];
            /* Get CBPCY */
            cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
            for (i = 0; i < 6; i++) {
                val = ((cbp >> (5 - i)) & 1);
                s->dc_val[0][s->block_index[i]] = 0;
                s->mb_intra                     = 0;
                if (i < 4) {
                    dmv_x = dmv_y = 0;
                    s->mb_intra   = 0;
                    mb_has_coeffs = 0;
                    if (val) {
                        GET_MVDATA(dmv_x, dmv_y);
                    }
                    vc1_pred_mv(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], 0, 0);
                    if (!s->mb_intra)
                        vc1_mc_4mv_luma(v, i, 0, 0);
                    intra_count += s->mb_intra;
                    is_intra[i]  = s->mb_intra;
                    is_coded[i]  = mb_has_coeffs;
                }
                if (i & 4) {
                    is_intra[i] = (intra_count >= 3);
                    is_coded[i] = val;
                }
                if (i == 4)
                    vc1_mc_4mv_chroma(v, 0);
                v->mb_type[0][s->block_index[i]] = is_intra[i];
                if (!coded_inter)
                    coded_inter = !is_intra[i] & is_coded[i];
            }
            // if there are no coded blocks then don't do anything more
            dst_idx = 0;
            if (!intra_count && !coded_inter)
                goto end;
            GET_MQUANT();
            s->current_picture.qscale_table[mb_pos] = mquant;
            /* test if block is intra and has pred */
            {
                int intrapred = 0;
                for (i = 0; i < 6; i++)
                    if (is_intra[i]) {
                        if (((!s->first_slice_line || (i == 2 || i == 3)) && v->mb_type[0][s->block_index[i] - s->block_wrap[i]])
                            || ((s->mb_x || (i == 1 || i == 3)) && v->mb_type[0][s->block_index[i] - 1])) {
                            intrapred = 1;
                            break;
                        }
                    }
                if (intrapred)
                    s->ac_pred = get_bits1(gb);
                else
                    s->ac_pred = 0;
            }
            if (!v->ttmbf && coded_inter)
                ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
            for (i = 0; i < 6; i++) {
                dst_idx    += i >> 2;
                off         = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                s->mb_intra = is_intra[i];
                if (is_intra[i]) {
                    /* check if prediction blocks A and C are available */
                    v->a_avail = v->c_avail = 0;
                    if (i == 2 || i == 3 || !s->first_slice_line)
                        v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                    if (i == 1 || i == 3 || s->mb_x)
                        v->c_avail = v->mb_type[0][s->block_index[i] - 1];

                    vc1_decode_intra_block(v, s->block[i], i, is_coded[i], mquant,
                                           (i & 4) ? v->codingset2 : v->codingset);
                    if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                        continue;
                    v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                    if (v->rangeredfrm)
                        for (j = 0; j < 64; j++)
                            s->block[i][j] <<= 1;
                    s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off,
                                                     (i & 4) ? s->uvlinesize : s->linesize);
                    if (v->pq >= 9 && v->overlap) {
                        if (v->c_avail)
                            v->vc1dsp.vc1_h_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                        if (v->a_avail)
                            v->vc1dsp.vc1_v_overlap(s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
                    }
                    block_cbp   |= 0xF << (i << 2);
                    block_intra |= 1 << i;
                } else if (is_coded[i]) {
                    pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                             first_block, s->dest[dst_idx] + off,
                                             (i & 4) ? s->uvlinesize : s->linesize,
                                             (i & 4) && (s->flags & CODEC_FLAG_GRAY),
                                             &block_tt);
                    block_cbp |= pat << (i << 2);
                    if (!v->ttmbf && ttmb < 8)
                        ttmb = -1;
                    first_block = 0;
                }
            }
        } else { // skipped MB
            s->mb_intra                               = 0;
            s->current_picture.qscale_table[mb_pos] = 0;
            for (i = 0; i < 6; i++) {
                v->mb_type[0][s->block_index[i]] = 0;
                s->dc_val[0][s->block_index[i]]  = 0;
            }
            for (i = 0; i < 4; i++) {
                vc1_pred_mv(v, i, 0, 0, 0, v->range_x, v->range_y, v->mb_type[0], 0, 0);
                vc1_mc_4mv_luma(v, i, 0, 0);
            }
            vc1_mc_4mv_chroma(v, 0);
            s->current_picture.qscale_table[mb_pos] = 0;
        }
    }
end:
    v->cbp[s->mb_x]      = block_cbp;
    v->ttblk[s->mb_x]    = block_tt;
    v->is_intra[s->mb_x] = block_intra;

    return 0;
}

/* Decode one macroblock in an interlaced frame p picture */

static int vc1_decode_p_mb_intfr(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp = 0; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */

    int mb_has_coeffs = 1; /* last_flag */
    int dmv_x, dmv_y; /* Differential MV components */
    int val; /* temp value */
    int first_block = 1;
    int dst_idx, off;
    int skipped, fourmv = 0, twomv = 0;
    int block_cbp = 0, pat, block_tt = 0;
    int idx_mbmode = 0, mvbp;
    int stride_y, fieldtx;

    mquant = v->pq; /* Lossy initialization */

    if (v->skip_is_raw)
        skipped = get_bits1(gb);
    else
        skipped = v->s.mbskip_table[mb_pos];
    if (!skipped) {
        if (v->fourmvswitch)
            idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_4MV_MBMODE_VLC_BITS, 2); // try getting this done
        else
            idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_NON4MV_MBMODE_VLC_BITS, 2); // in a single line
        switch (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0]) {
        /* store the motion vector type in a flag (useful later) */
        case MV_PMODE_INTFR_4MV:
            fourmv = 1;
            v->blk_mv_type[s->block_index[0]] = 0;
            v->blk_mv_type[s->block_index[1]] = 0;
            v->blk_mv_type[s->block_index[2]] = 0;
            v->blk_mv_type[s->block_index[3]] = 0;
            break;
        case MV_PMODE_INTFR_4MV_FIELD:
            fourmv = 1;
            v->blk_mv_type[s->block_index[0]] = 1;
            v->blk_mv_type[s->block_index[1]] = 1;
            v->blk_mv_type[s->block_index[2]] = 1;
            v->blk_mv_type[s->block_index[3]] = 1;
            break;
        case MV_PMODE_INTFR_2MV_FIELD:
            twomv = 1;
            v->blk_mv_type[s->block_index[0]] = 1;
            v->blk_mv_type[s->block_index[1]] = 1;
            v->blk_mv_type[s->block_index[2]] = 1;
            v->blk_mv_type[s->block_index[3]] = 1;
            break;
        case MV_PMODE_INTFR_1MV:
            v->blk_mv_type[s->block_index[0]] = 0;
            v->blk_mv_type[s->block_index[1]] = 0;
            v->blk_mv_type[s->block_index[2]] = 0;
            v->blk_mv_type[s->block_index[3]] = 0;
            break;
        }
        if (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_INTRA) { // intra MB
            for (i = 0; i < 4; i++) {
                s->current_picture.motion_val[1][s->block_index[i]][0] = 0;
                s->current_picture.motion_val[1][s->block_index[i]][1] = 0;
            }
            s->current_picture.mb_type[mb_pos]                     = MB_TYPE_INTRA;
            s->mb_intra = v->is_intra[s->mb_x] = 1;
            for (i = 0; i < 6; i++)
                v->mb_type[0][s->block_index[i]] = 1;
            fieldtx = v->fieldtx_plane[mb_pos] = get_bits1(gb);
            mb_has_coeffs = get_bits1(gb);
            if (mb_has_coeffs)
                cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
            v->s.ac_pred = v->acpred_plane[mb_pos] = get_bits1(gb);
            GET_MQUANT();
            s->current_picture.qscale_table[mb_pos] = mquant;
            /* Set DC scale - y and c use the same (not sure if necessary here) */
            s->y_dc_scale = s->y_dc_scale_table[mquant];
            s->c_dc_scale = s->c_dc_scale_table[mquant];
            dst_idx = 0;
            for (i = 0; i < 6; i++) {
                s->dc_val[0][s->block_index[i]] = 0;
                dst_idx += i >> 2;
                val = ((cbp >> (5 - i)) & 1);
                v->mb_type[0][s->block_index[i]] = s->mb_intra;
                v->a_avail = v->c_avail = 0;
                if (i == 2 || i == 3 || !s->first_slice_line)
                    v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
                if (i == 1 || i == 3 || s->mb_x)
                    v->c_avail = v->mb_type[0][s->block_index[i] - 1];

                vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                       (i & 4) ? v->codingset2 : v->codingset);
                if ((i>3) && (s->flags & CODEC_FLAG_GRAY)) continue;
                v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
                if (i < 4) {
                    stride_y = s->linesize << fieldtx;
                    off = (fieldtx) ? ((i & 1) * 8) + ((i & 2) >> 1) * s->linesize : (i & 1) * 8 + 4 * (i & 2) * s->linesize;
                } else {
                    stride_y = s->uvlinesize;
                    off = 0;
                }
                s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, stride_y);
                //TODO: loop filter
            }

        } else { // inter MB
            mb_has_coeffs = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][3];
            if (mb_has_coeffs)
                cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
            if (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_2MV_FIELD) {
                v->twomvbp = get_vlc2(gb, v->twomvbp_vlc->table, VC1_2MV_BLOCK_PATTERN_VLC_BITS, 1);
            } else {
                if ((ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_4MV)
                    || (ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][0] == MV_PMODE_INTFR_4MV_FIELD)) {
                    v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
                }
            }
            s->mb_intra = v->is_intra[s->mb_x] = 0;
            for (i = 0; i < 6; i++)
                v->mb_type[0][s->block_index[i]] = 0;
            fieldtx = v->fieldtx_plane[mb_pos] = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][1];
            /* for all motion vector read MVDATA and motion compensate each block */
            dst_idx = 0;
            if (fourmv) {
                mvbp = v->fourmvbp;
                for (i = 0; i < 6; i++) {
                    if (i < 4) {
                        dmv_x = dmv_y = 0;
                        val   = ((mvbp >> (3 - i)) & 1);
                        if (val) {
                            get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                        }
                        vc1_pred_mv_intfr(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], 0);
                        vc1_mc_4mv_luma(v, i, 0, 0);
                    } else if (i == 4) {
                        vc1_mc_4mv_chroma4(v, 0, 0, 0);
                    }
                }
            } else if (twomv) {
                mvbp  = v->twomvbp;
                dmv_x = dmv_y = 0;
                if (mvbp & 2) {
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                }
                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], 0);
                vc1_mc_4mv_luma(v, 0, 0, 0);
                vc1_mc_4mv_luma(v, 1, 0, 0);
                dmv_x = dmv_y = 0;
                if (mvbp & 1) {
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                }
                vc1_pred_mv_intfr(v, 2, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], 0);
                vc1_mc_4mv_luma(v, 2, 0, 0);
                vc1_mc_4mv_luma(v, 3, 0, 0);
                vc1_mc_4mv_chroma4(v, 0, 0, 0);
            } else {
                mvbp = ff_vc1_mbmode_intfrp[v->fourmvswitch][idx_mbmode][2];
                dmv_x = dmv_y = 0;
                if (mvbp) {
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                }
                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                vc1_mc_1mv(v, 0);
            }
            if (cbp)
                GET_MQUANT();  // p. 227
            s->current_picture.qscale_table[mb_pos] = mquant;
            if (!v->ttmbf && cbp)
                ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
            for (i = 0; i < 6; i++) {
                s->dc_val[0][s->block_index[i]] = 0;
                dst_idx += i >> 2;
                val = ((cbp >> (5 - i)) & 1);
                if (!fieldtx)
                    off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                else
                    off = (i & 4) ? 0 : ((i & 1) * 8 + ((i > 1) * s->linesize));
                if (val) {
                    pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                             first_block, s->dest[dst_idx] + off,
                                             (i & 4) ? s->uvlinesize : (s->linesize << fieldtx),
                                             (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                    block_cbp |= pat << (i << 2);
                    if (!v->ttmbf && ttmb < 8)
                        ttmb = -1;
                    first_block = 0;
                }
            }
        }
    } else { // skipped
        s->mb_intra = v->is_intra[s->mb_x] = 0;
        for (i = 0; i < 6; i++) {
            v->mb_type[0][s->block_index[i]] = 0;
            s->dc_val[0][s->block_index[i]] = 0;
        }
        s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
        s->current_picture.qscale_table[mb_pos] = 0;
        v->blk_mv_type[s->block_index[0]] = 0;
        v->blk_mv_type[s->block_index[1]] = 0;
        v->blk_mv_type[s->block_index[2]] = 0;
        v->blk_mv_type[s->block_index[3]] = 0;
        vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0);
        vc1_mc_1mv(v, 0);
    }
    if (s->mb_x == s->mb_width - 1)
        memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0])*s->mb_stride);
    return 0;
}

static int vc1_decode_p_mb_intfi(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp = 0; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */

    int mb_has_coeffs = 1; /* last_flag */
    int dmv_x, dmv_y; /* Differential MV components */
    int val; /* temp values */
    int first_block = 1;
    int dst_idx, off;
    int pred_flag = 0;
    int block_cbp = 0, pat, block_tt = 0;
    int idx_mbmode = 0;

    mquant = v->pq; /* Lossy initialization */

    idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_IF_MBMODE_VLC_BITS, 2);
    if (idx_mbmode <= 1) { // intra MB
        s->mb_intra = v->is_intra[s->mb_x] = 1;
        s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
        s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;
        s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_INTRA;
        GET_MQUANT();
        s->current_picture.qscale_table[mb_pos] = mquant;
        /* Set DC scale - y and c use the same (not sure if necessary here) */
        s->y_dc_scale = s->y_dc_scale_table[mquant];
        s->c_dc_scale = s->c_dc_scale_table[mquant];
        v->s.ac_pred  = v->acpred_plane[mb_pos] = get_bits1(gb);
        mb_has_coeffs = idx_mbmode & 1;
        if (mb_has_coeffs)
            cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_ICBPCY_VLC_BITS, 2);
        dst_idx = 0;
        for (i = 0; i < 6; i++) {
            s->dc_val[0][s->block_index[i]]  = 0;
            v->mb_type[0][s->block_index[i]] = 1;
            dst_idx += i >> 2;
            val = ((cbp >> (5 - i)) & 1);
            v->a_avail = v->c_avail = 0;
            if (i == 2 || i == 3 || !s->first_slice_line)
                v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
            if (i == 1 || i == 3 || s->mb_x)
                v->c_avail = v->mb_type[0][s->block_index[i] - 1];

            vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                   (i & 4) ? v->codingset2 : v->codingset);
            if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                continue;
            v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
            off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
            s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize);
            // TODO: loop filter
        }
    } else {
        s->mb_intra = v->is_intra[s->mb_x] = 0;
        s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_16x16;
        for (i = 0; i < 6; i++) v->mb_type[0][s->block_index[i]] = 0;
        if (idx_mbmode <= 5) { // 1-MV
            dmv_x = dmv_y = pred_flag = 0;
            if (idx_mbmode & 1) {
                get_mvdata_interlaced(v, &dmv_x, &dmv_y, &pred_flag);
            }
            vc1_pred_mv(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], pred_flag, 0);
            vc1_mc_1mv(v, 0);
            mb_has_coeffs = !(idx_mbmode & 2);
        } else { // 4-MV
            v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
            for (i = 0; i < 6; i++) {
                if (i < 4) {
                    dmv_x = dmv_y = pred_flag = 0;
                    val   = ((v->fourmvbp >> (3 - i)) & 1);
                    if (val) {
                        get_mvdata_interlaced(v, &dmv_x, &dmv_y, &pred_flag);
                    }
                    vc1_pred_mv(v, i, dmv_x, dmv_y, 0, v->range_x, v->range_y, v->mb_type[0], pred_flag, 0);
                    vc1_mc_4mv_luma(v, i, 0, 0);
                } else if (i == 4)
                    vc1_mc_4mv_chroma(v, 0);
            }
            mb_has_coeffs = idx_mbmode & 1;
        }
        if (mb_has_coeffs)
            cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
        if (cbp) {
            GET_MQUANT();
        }
        s->current_picture.qscale_table[mb_pos] = mquant;
        if (!v->ttmbf && cbp) {
            ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
        }
        dst_idx = 0;
        for (i = 0; i < 6; i++) {
            s->dc_val[0][s->block_index[i]] = 0;
            dst_idx += i >> 2;
            val = ((cbp >> (5 - i)) & 1);
            off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
            if (val) {
                pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                         first_block, s->dest[dst_idx] + off,
                                         (i & 4) ? s->uvlinesize : s->linesize,
                                         (i & 4) && (s->flags & CODEC_FLAG_GRAY),
                                         &block_tt);
                block_cbp |= pat << (i << 2);
                if (!v->ttmbf && ttmb < 8) ttmb = -1;
                first_block = 0;
            }
        }
    }
    if (s->mb_x == s->mb_width - 1)
        memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
    return 0;
}

/** Decode one B-frame MB (in Main profile)
 */
static void vc1_decode_b_mb(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i, j;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp = 0; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */
    int mb_has_coeffs = 0; /* last_flag */
    int index, index1; /* LUT indexes */
    int val, sign; /* temp values */
    int first_block = 1;
    int dst_idx, off;
    int skipped, direct;
    int dmv_x[2], dmv_y[2];
    int bmvtype = BMV_TYPE_BACKWARD;

    mquant      = v->pq; /* lossy initialization */
    s->mb_intra = 0;

    if (v->dmb_is_raw)
        direct = get_bits1(gb);
    else
        direct = v->direct_mb_plane[mb_pos];
    if (v->skip_is_raw)
        skipped = get_bits1(gb);
    else
        skipped = v->s.mbskip_table[mb_pos];

    dmv_x[0] = dmv_x[1] = dmv_y[0] = dmv_y[1] = 0;
    for (i = 0; i < 6; i++) {
        v->mb_type[0][s->block_index[i]] = 0;
        s->dc_val[0][s->block_index[i]]  = 0;
    }
    s->current_picture.qscale_table[mb_pos] = 0;

    if (!direct) {
        if (!skipped) {
            GET_MVDATA(dmv_x[0], dmv_y[0]);
            dmv_x[1] = dmv_x[0];
            dmv_y[1] = dmv_y[0];
        }
        if (skipped || !s->mb_intra) {
            bmvtype = decode012(gb);
            switch (bmvtype) {
            case 0:
                bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_BACKWARD : BMV_TYPE_FORWARD;
                break;
            case 1:
                bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_FORWARD : BMV_TYPE_BACKWARD;
                break;
            case 2:
                bmvtype  = BMV_TYPE_INTERPOLATED;
                dmv_x[0] = dmv_y[0] = 0;
            }
        }
    }
    for (i = 0; i < 6; i++)
        v->mb_type[0][s->block_index[i]] = s->mb_intra;

    if (skipped) {
        if (direct)
            bmvtype = BMV_TYPE_INTERPOLATED;
        vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
        vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
        return;
    }
    if (direct) {
        cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
        GET_MQUANT();
        s->mb_intra = 0;
        s->current_picture.qscale_table[mb_pos] = mquant;
        if (!v->ttmbf)
            ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
        dmv_x[0] = dmv_y[0] = dmv_x[1] = dmv_y[1] = 0;
        vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
        vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
    } else {
        if (!mb_has_coeffs && !s->mb_intra) {
            /* no coded blocks - effectively skipped */
            vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
            vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
            return;
        }
        if (s->mb_intra && !mb_has_coeffs) {
            GET_MQUANT();
            s->current_picture.qscale_table[mb_pos] = mquant;
            s->ac_pred = get_bits1(gb);
            cbp = 0;
            vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
        } else {
            if (bmvtype == BMV_TYPE_INTERPOLATED) {
                GET_MVDATA(dmv_x[0], dmv_y[0]);
                if (!mb_has_coeffs) {
                    /* interpolated skipped block */
                    vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
                    vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
                    return;
                }
            }
            vc1_pred_b_mv(v, dmv_x, dmv_y, direct, bmvtype);
            if (!s->mb_intra) {
                vc1_b_mc(v, dmv_x, dmv_y, direct, bmvtype);
            }
            if (s->mb_intra)
                s->ac_pred = get_bits1(gb);
            cbp = get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
            GET_MQUANT();
            s->current_picture.qscale_table[mb_pos] = mquant;
            if (!v->ttmbf && !s->mb_intra && mb_has_coeffs)
                ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
        }
    }
    dst_idx = 0;
    for (i = 0; i < 6; i++) {
        s->dc_val[0][s->block_index[i]] = 0;
        dst_idx += i >> 2;
        val = ((cbp >> (5 - i)) & 1);
        off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
        v->mb_type[0][s->block_index[i]] = s->mb_intra;
        if (s->mb_intra) {
            /* check if prediction blocks A and C are available */
            v->a_avail = v->c_avail = 0;
            if (i == 2 || i == 3 || !s->first_slice_line)
                v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
            if (i == 1 || i == 3 || s->mb_x)
                v->c_avail = v->mb_type[0][s->block_index[i] - 1];

            vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                   (i & 4) ? v->codingset2 : v->codingset);
            if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                continue;
            v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
            if (v->rangeredfrm)
                for (j = 0; j < 64; j++)
                    s->block[i][j] <<= 1;
            s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, i & 4 ? s->uvlinesize : s->linesize);
        } else if (val) {
            vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                               first_block, s->dest[dst_idx] + off,
                               (i & 4) ? s->uvlinesize : s->linesize,
                               (i & 4) && (s->flags & CODEC_FLAG_GRAY), NULL);
            if (!v->ttmbf && ttmb < 8)
                ttmb = -1;
            first_block = 0;
        }
    }
}

/** Decode one B-frame MB (in interlaced field B picture)
 */
static void vc1_decode_b_mb_intfi(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i, j;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp = 0; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */
    int mb_has_coeffs = 0; /* last_flag */
    int val; /* temp value */
    int first_block = 1;
    int dst_idx, off;
    int fwd;
    int dmv_x[2], dmv_y[2], pred_flag[2];
    int bmvtype = BMV_TYPE_BACKWARD;
    int idx_mbmode;

    mquant      = v->pq; /* Lossy initialization */
    s->mb_intra = 0;

    idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_IF_MBMODE_VLC_BITS, 2);
    if (idx_mbmode <= 1) { // intra MB
        s->mb_intra = v->is_intra[s->mb_x] = 1;
        s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
        s->current_picture.motion_val[1][s->block_index[0]][1] = 0;
        s->current_picture.mb_type[mb_pos + v->mb_off]         = MB_TYPE_INTRA;
        GET_MQUANT();
        s->current_picture.qscale_table[mb_pos] = mquant;
        /* Set DC scale - y and c use the same (not sure if necessary here) */
        s->y_dc_scale = s->y_dc_scale_table[mquant];
        s->c_dc_scale = s->c_dc_scale_table[mquant];
        v->s.ac_pred  = v->acpred_plane[mb_pos] = get_bits1(gb);
        mb_has_coeffs = idx_mbmode & 1;
        if (mb_has_coeffs)
            cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_ICBPCY_VLC_BITS, 2);
        dst_idx = 0;
        for (i = 0; i < 6; i++) {
            s->dc_val[0][s->block_index[i]] = 0;
            dst_idx += i >> 2;
            val = ((cbp >> (5 - i)) & 1);
            v->mb_type[0][s->block_index[i]] = s->mb_intra;
            v->a_avail                       = v->c_avail = 0;
            if (i == 2 || i == 3 || !s->first_slice_line)
                v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
            if (i == 1 || i == 3 || s->mb_x)
                v->c_avail = v->mb_type[0][s->block_index[i] - 1];

            vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                   (i & 4) ? v->codingset2 : v->codingset);
            if ((i>3) && (s->flags & CODEC_FLAG_GRAY))
                continue;
            v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
            if (v->rangeredfrm)
                for (j = 0; j < 64; j++)
                    s->block[i][j] <<= 1;
            off  = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
            s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, (i & 4) ? s->uvlinesize : s->linesize);
            // TODO: yet to perform loop filter
        }
    } else {
        s->mb_intra = v->is_intra[s->mb_x] = 0;
        s->current_picture.mb_type[mb_pos + v->mb_off] = MB_TYPE_16x16;
        for (i = 0; i < 6; i++) v->mb_type[0][s->block_index[i]] = 0;
        if (v->fmb_is_raw)
            fwd = v->forward_mb_plane[mb_pos] = get_bits1(gb);
        else
            fwd = v->forward_mb_plane[mb_pos];
        if (idx_mbmode <= 5) { // 1-MV
            int interpmvp = 0;
            dmv_x[0]     = dmv_x[1] = dmv_y[0] = dmv_y[1] = 0;
            pred_flag[0] = pred_flag[1] = 0;
            if (fwd)
                bmvtype = BMV_TYPE_FORWARD;
            else {
                bmvtype = decode012(gb);
                switch (bmvtype) {
                case 0:
                    bmvtype = BMV_TYPE_BACKWARD;
                    break;
                case 1:
                    bmvtype = BMV_TYPE_DIRECT;
                    break;
                case 2:
                    bmvtype   = BMV_TYPE_INTERPOLATED;
                    interpmvp = get_bits1(gb);
                }
            }
            v->bmvtype = bmvtype;
            if (bmvtype != BMV_TYPE_DIRECT && idx_mbmode & 1) {
                get_mvdata_interlaced(v, &dmv_x[bmvtype == BMV_TYPE_BACKWARD], &dmv_y[bmvtype == BMV_TYPE_BACKWARD], &pred_flag[bmvtype == BMV_TYPE_BACKWARD]);
            }
            if (interpmvp) {
                get_mvdata_interlaced(v, &dmv_x[1], &dmv_y[1], &pred_flag[1]);
            }
            if (bmvtype == BMV_TYPE_DIRECT) {
                dmv_x[0] = dmv_y[0] = pred_flag[0] = 0;
                dmv_x[1] = dmv_y[1] = pred_flag[0] = 0;
            }
            vc1_pred_b_mv_intfi(v, 0, dmv_x, dmv_y, 1, pred_flag);
            vc1_b_mc(v, dmv_x, dmv_y, (bmvtype == BMV_TYPE_DIRECT), bmvtype);
            mb_has_coeffs = !(idx_mbmode & 2);
        } else { // 4-MV
            if (fwd)
                bmvtype = BMV_TYPE_FORWARD;
            v->bmvtype  = bmvtype;
            v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
            for (i = 0; i < 6; i++) {
                if (i < 4) {
                    dmv_x[0] = dmv_y[0] = pred_flag[0] = 0;
                    dmv_x[1] = dmv_y[1] = pred_flag[1] = 0;
                    val = ((v->fourmvbp >> (3 - i)) & 1);
                    if (val) {
                        get_mvdata_interlaced(v, &dmv_x[bmvtype == BMV_TYPE_BACKWARD],
                                                 &dmv_y[bmvtype == BMV_TYPE_BACKWARD],
                                             &pred_flag[bmvtype == BMV_TYPE_BACKWARD]);
                    }
                    vc1_pred_b_mv_intfi(v, i, dmv_x, dmv_y, 0, pred_flag);
                    vc1_mc_4mv_luma(v, i, bmvtype == BMV_TYPE_BACKWARD, 0);
                } else if (i == 4)
                    vc1_mc_4mv_chroma(v, bmvtype == BMV_TYPE_BACKWARD);
            }
            mb_has_coeffs = idx_mbmode & 1;
        }
        if (mb_has_coeffs)
            cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
        if (cbp) {
            GET_MQUANT();
        }
        s->current_picture.qscale_table[mb_pos] = mquant;
        if (!v->ttmbf && cbp) {
            ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
        }
        dst_idx = 0;
        for (i = 0; i < 6; i++) {
            s->dc_val[0][s->block_index[i]] = 0;
            dst_idx += i >> 2;
            val = ((cbp >> (5 - i)) & 1);
            off = (i & 4) ? 0 : (i & 1) * 8 + (i & 2) * 4 * s->linesize;
            if (val) {
                vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                   first_block, s->dest[dst_idx] + off,
                                   (i & 4) ? s->uvlinesize : s->linesize,
                                   (i & 4) && (s->flags & CODEC_FLAG_GRAY), NULL);
                if (!v->ttmbf && ttmb < 8)
                    ttmb = -1;
                first_block = 0;
            }
        }
    }
}

/** Decode one B-frame MB (in interlaced frame B picture)
 */
static int vc1_decode_b_mb_intfr(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    GetBitContext *gb = &s->gb;
    int i, j;
    int mb_pos = s->mb_x + s->mb_y * s->mb_stride;
    int cbp = 0; /* cbp decoding stuff */
    int mqdiff, mquant; /* MB quantization */
    int ttmb = v->ttfrm; /* MB Transform type */
    int mvsw = 0; /* motion vector switch */
    int mb_has_coeffs = 1; /* last_flag */
    int dmv_x, dmv_y; /* Differential MV components */
    int val; /* temp value */
    int first_block = 1;
    int dst_idx, off;
    int skipped, direct, twomv = 0;
    int block_cbp = 0, pat, block_tt = 0;
    int idx_mbmode = 0, mvbp;
    int stride_y, fieldtx;
    int bmvtype = BMV_TYPE_BACKWARD;
    int dir, dir2;

    mquant = v->pq; /* Lossy initialization */
    s->mb_intra = 0;
    if (v->skip_is_raw)
        skipped = get_bits1(gb);
    else
        skipped = v->s.mbskip_table[mb_pos];

    if (!skipped) {
        idx_mbmode = get_vlc2(gb, v->mbmode_vlc->table, VC1_INTFR_NON4MV_MBMODE_VLC_BITS, 2);
        if (ff_vc1_mbmode_intfrp[0][idx_mbmode][0] == MV_PMODE_INTFR_2MV_FIELD) {
            twomv = 1;
            v->blk_mv_type[s->block_index[0]] = 1;
            v->blk_mv_type[s->block_index[1]] = 1;
            v->blk_mv_type[s->block_index[2]] = 1;
            v->blk_mv_type[s->block_index[3]] = 1;
        } else {
            v->blk_mv_type[s->block_index[0]] = 0;
            v->blk_mv_type[s->block_index[1]] = 0;
            v->blk_mv_type[s->block_index[2]] = 0;
            v->blk_mv_type[s->block_index[3]] = 0;
        }
    }

    if (v->dmb_is_raw)
        direct = get_bits1(gb);
    else
        direct = v->direct_mb_plane[mb_pos];

    if (direct) {
        s->mv[0][0][0] = s->current_picture.motion_val[0][s->block_index[0]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][0], v->bfraction, 0, s->quarter_sample);
        s->mv[0][0][1] = s->current_picture.motion_val[0][s->block_index[0]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][1], v->bfraction, 0, s->quarter_sample);
        s->mv[1][0][0] = s->current_picture.motion_val[1][s->block_index[0]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][0], v->bfraction, 1, s->quarter_sample);
        s->mv[1][0][1] = s->current_picture.motion_val[1][s->block_index[0]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0]][1], v->bfraction, 1, s->quarter_sample);

        if (twomv) {
            s->mv[0][2][0] = s->current_picture.motion_val[0][s->block_index[2]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][0], v->bfraction, 0, s->quarter_sample);
            s->mv[0][2][1] = s->current_picture.motion_val[0][s->block_index[2]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][1], v->bfraction, 0, s->quarter_sample);
            s->mv[1][2][0] = s->current_picture.motion_val[1][s->block_index[2]][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][0], v->bfraction, 1, s->quarter_sample);
            s->mv[1][2][1] = s->current_picture.motion_val[1][s->block_index[2]][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[2]][1], v->bfraction, 1, s->quarter_sample);

            for (i = 1; i < 4; i += 2) {
                s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = s->mv[0][i-1][0];
                s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = s->mv[0][i-1][1];
                s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = s->mv[1][i-1][0];
                s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = s->mv[1][i-1][1];
            }
        } else {
            for (i = 1; i < 4; i++) {
                s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = s->mv[0][0][0];
                s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = s->mv[0][0][1];
                s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = s->mv[1][0][0];
                s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = s->mv[1][0][1];
            }
        }
    }

    if (ff_vc1_mbmode_intfrp[0][idx_mbmode][0] == MV_PMODE_INTFR_INTRA) { // intra MB
        for (i = 0; i < 4; i++) {
            s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0] = 0;
            s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1] = 0;
            s->mv[1][i][0] = s->current_picture.motion_val[1][s->block_index[i]][0] = 0;
            s->mv[1][i][1] = s->current_picture.motion_val[1][s->block_index[i]][1] = 0;
        }
        s->current_picture.mb_type[mb_pos] = MB_TYPE_INTRA;
        s->mb_intra = v->is_intra[s->mb_x] = 1;
        for (i = 0; i < 6; i++)
            v->mb_type[0][s->block_index[i]] = 1;
        fieldtx = v->fieldtx_plane[mb_pos] = get_bits1(gb);
        mb_has_coeffs = get_bits1(gb);
        if (mb_has_coeffs)
            cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
        v->s.ac_pred = v->acpred_plane[mb_pos] = get_bits1(gb);
        GET_MQUANT();
        s->current_picture.qscale_table[mb_pos] = mquant;
        /* Set DC scale - y and c use the same (not sure if necessary here) */
        s->y_dc_scale = s->y_dc_scale_table[mquant];
        s->c_dc_scale = s->c_dc_scale_table[mquant];
        dst_idx = 0;
        for (i = 0; i < 6; i++) {
            s->dc_val[0][s->block_index[i]] = 0;
            dst_idx += i >> 2;
            val = ((cbp >> (5 - i)) & 1);
            v->mb_type[0][s->block_index[i]] = s->mb_intra;
            v->a_avail = v->c_avail = 0;
            if (i == 2 || i == 3 || !s->first_slice_line)
                v->a_avail = v->mb_type[0][s->block_index[i] - s->block_wrap[i]];
            if (i == 1 || i == 3 || s->mb_x)
                v->c_avail = v->mb_type[0][s->block_index[i] - 1];

            vc1_decode_intra_block(v, s->block[i], i, val, mquant,
                                   (i & 4) ? v->codingset2 : v->codingset);
            if (i > 3 && (s->flags & CODEC_FLAG_GRAY))
                continue;
            v->vc1dsp.vc1_inv_trans_8x8(s->block[i]);
            if (i < 4) {
                stride_y = s->linesize << fieldtx;
                off = (fieldtx) ? ((i & 1) * 8) + ((i & 2) >> 1) * s->linesize : (i & 1) * 8 + 4 * (i & 2) * s->linesize;
            } else {
                stride_y = s->uvlinesize;
                off = 0;
            }
            s->dsp.put_signed_pixels_clamped(s->block[i], s->dest[dst_idx] + off, stride_y);
        }
    } else {
        s->mb_intra = v->is_intra[s->mb_x] = 0;
        if (!direct) {
            if (skipped || !s->mb_intra) {
                bmvtype = decode012(gb);
                switch (bmvtype) {
                case 0:
                    bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_BACKWARD : BMV_TYPE_FORWARD;
                    break;
                case 1:
                    bmvtype = (v->bfraction >= (B_FRACTION_DEN/2)) ? BMV_TYPE_FORWARD : BMV_TYPE_BACKWARD;
                    break;
                case 2:
                    bmvtype  = BMV_TYPE_INTERPOLATED;
                }
            }

            if (twomv && bmvtype != BMV_TYPE_INTERPOLATED)
                mvsw = get_bits1(gb);
        }

        if (!skipped) { // inter MB
            mb_has_coeffs = ff_vc1_mbmode_intfrp[0][idx_mbmode][3];
            if (mb_has_coeffs)
                cbp = 1 + get_vlc2(&v->s.gb, v->cbpcy_vlc->table, VC1_CBPCY_P_VLC_BITS, 2);
            if (!direct) {
                if (bmvtype == BMV_TYPE_INTERPOLATED & twomv) {
                    v->fourmvbp = get_vlc2(gb, v->fourmvbp_vlc->table, VC1_4MV_BLOCK_PATTERN_VLC_BITS, 1);
                } else if (bmvtype == BMV_TYPE_INTERPOLATED | twomv) {
                    v->twomvbp = get_vlc2(gb, v->twomvbp_vlc->table, VC1_2MV_BLOCK_PATTERN_VLC_BITS, 1);
                }
            }

            for (i = 0; i < 6; i++)
                v->mb_type[0][s->block_index[i]] = 0;
            fieldtx = v->fieldtx_plane[mb_pos] = ff_vc1_mbmode_intfrp[0][idx_mbmode][1];
            /* for all motion vector read MVDATA and motion compensate each block */
            dst_idx = 0;
            if (direct) {
                if (twomv) {
                    for (i = 0; i < 4; i++) {
                        vc1_mc_4mv_luma(v, i, 0, 0);
                        vc1_mc_4mv_luma(v, i, 1, 1);
                    }
                    vc1_mc_4mv_chroma4(v, 0, 0, 0);
                    vc1_mc_4mv_chroma4(v, 1, 1, 1);
                } else {
                    vc1_mc_1mv(v, 0);
                    vc1_interp_mc(v);
                }
            } else if (twomv && bmvtype == BMV_TYPE_INTERPOLATED) {
                mvbp = v->fourmvbp;
                for (i = 0; i < 4; i++) {
                    dir = i==1 || i==3;
                    dmv_x = dmv_y = 0;
                    val = ((mvbp >> (3 - i)) & 1);
                    if (val)
                        get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                    j = i > 1 ? 2 : 0;
                    vc1_pred_mv_intfr(v, j, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir);
                    vc1_mc_4mv_luma(v, j, dir, dir);
                    vc1_mc_4mv_luma(v, j+1, dir, dir);
                }

                vc1_mc_4mv_chroma4(v, 0, 0, 0);
                vc1_mc_4mv_chroma4(v, 1, 1, 1);
            } else if (bmvtype == BMV_TYPE_INTERPOLATED) {
                mvbp = v->twomvbp;
                dmv_x = dmv_y = 0;
                if (mvbp & 2)
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);

                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                vc1_mc_1mv(v, 0);

                dmv_x = dmv_y = 0;
                if (mvbp & 1)
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);

                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], 1);
                vc1_interp_mc(v);
            } else if (twomv) {
                dir = bmvtype == BMV_TYPE_BACKWARD;
                dir2 = dir;
                if (mvsw)
                    dir2 = !dir;
                mvbp = v->twomvbp;
                dmv_x = dmv_y = 0;
                if (mvbp & 2)
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir);

                dmv_x = dmv_y = 0;
                if (mvbp & 1)
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);
                vc1_pred_mv_intfr(v, 2, dmv_x, dmv_y, 2, v->range_x, v->range_y, v->mb_type[0], dir2);

                if (mvsw) {
                    for (i = 0; i < 2; i++) {
                        s->mv[dir][i+2][0] = s->mv[dir][i][0] = s->current_picture.motion_val[dir][s->block_index[i+2]][0] = s->current_picture.motion_val[dir][s->block_index[i]][0];
                        s->mv[dir][i+2][1] = s->mv[dir][i][1] = s->current_picture.motion_val[dir][s->block_index[i+2]][1] = s->current_picture.motion_val[dir][s->block_index[i]][1];
                        s->mv[dir2][i+2][0] = s->mv[dir2][i][0] = s->current_picture.motion_val[dir2][s->block_index[i]][0] = s->current_picture.motion_val[dir2][s->block_index[i+2]][0];
                        s->mv[dir2][i+2][1] = s->mv[dir2][i][1] = s->current_picture.motion_val[dir2][s->block_index[i]][1] = s->current_picture.motion_val[dir2][s->block_index[i+2]][1];
                    }
                } else {
                    vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, v->mb_type[0], !dir);
                    vc1_pred_mv_intfr(v, 2, 0, 0, 2, v->range_x, v->range_y, v->mb_type[0], !dir);
                }

                vc1_mc_4mv_luma(v, 0, dir, 0);
                vc1_mc_4mv_luma(v, 1, dir, 0);
                vc1_mc_4mv_luma(v, 2, dir2, 0);
                vc1_mc_4mv_luma(v, 3, dir2, 0);
                vc1_mc_4mv_chroma4(v, dir, dir2, 0);
            } else {
                dir = bmvtype == BMV_TYPE_BACKWARD;

                mvbp = ff_vc1_mbmode_intfrp[0][idx_mbmode][2];
                dmv_x = dmv_y = 0;
                if (mvbp)
                    get_mvdata_interlaced(v, &dmv_x, &dmv_y, 0);

                vc1_pred_mv_intfr(v, 0, dmv_x, dmv_y, 1, v->range_x, v->range_y, v->mb_type[0], dir);
                v->blk_mv_type[s->block_index[0]] = 1;
                v->blk_mv_type[s->block_index[1]] = 1;
                v->blk_mv_type[s->block_index[2]] = 1;
                v->blk_mv_type[s->block_index[3]] = 1;
                vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, 0, !dir);
                for (i = 0; i < 2; i++) {
                    s->mv[!dir][i+2][0] = s->mv[!dir][i][0] = s->current_picture.motion_val[!dir][s->block_index[i+2]][0] = s->current_picture.motion_val[!dir][s->block_index[i]][0];
                    s->mv[!dir][i+2][1] = s->mv[!dir][i][1] = s->current_picture.motion_val[!dir][s->block_index[i+2]][1] = s->current_picture.motion_val[!dir][s->block_index[i]][1];
                }
                vc1_mc_1mv(v, dir);
            }

            if (cbp)
                GET_MQUANT();  // p. 227
            s->current_picture.qscale_table[mb_pos] = mquant;
            if (!v->ttmbf && cbp)
                ttmb = get_vlc2(gb, ff_vc1_ttmb_vlc[v->tt_index].table, VC1_TTMB_VLC_BITS, 2);
            for (i = 0; i < 6; i++) {
                s->dc_val[0][s->block_index[i]] = 0;
                dst_idx += i >> 2;
                val = ((cbp >> (5 - i)) & 1);
                if (!fieldtx)
                    off = (i & 4) ? 0 : ((i & 1) * 8 + (i & 2) * 4 * s->linesize);
                else
                    off = (i & 4) ? 0 : ((i & 1) * 8 + ((i > 1) * s->linesize));
                if (val) {
                    pat = vc1_decode_p_block(v, s->block[i], i, mquant, ttmb,
                                             first_block, s->dest[dst_idx] + off,
                                             (i & 4) ? s->uvlinesize : (s->linesize << fieldtx),
                                             (i & 4) && (s->flags & CODEC_FLAG_GRAY), &block_tt);
                    block_cbp |= pat << (i << 2);
                    if (!v->ttmbf && ttmb < 8)
                        ttmb = -1;
                    first_block = 0;
                }
            }

        } else { // skipped
            dir = 0;
            for (i = 0; i < 6; i++) {
                v->mb_type[0][s->block_index[i]] = 0;
                s->dc_val[0][s->block_index[i]] = 0;
            }
            s->current_picture.mb_type[mb_pos]      = MB_TYPE_SKIP;
            s->current_picture.qscale_table[mb_pos] = 0;
            v->blk_mv_type[s->block_index[0]] = 0;
            v->blk_mv_type[s->block_index[1]] = 0;
            v->blk_mv_type[s->block_index[2]] = 0;
            v->blk_mv_type[s->block_index[3]] = 0;

            if (!direct) {
                if (bmvtype == BMV_TYPE_INTERPOLATED) {
                    vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 0);
                    vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], 1);
                } else {
                    dir = bmvtype == BMV_TYPE_BACKWARD;
                    vc1_pred_mv_intfr(v, 0, 0, 0, 1, v->range_x, v->range_y, v->mb_type[0], dir);
                    if (mvsw) {
                        int dir2 = dir;
                        if (mvsw)
                            dir2 = !dir;
                        for (i = 0; i < 2; i++) {
                            s->mv[dir][i+2][0] = s->mv[dir][i][0] = s->current_picture.motion_val[dir][s->block_index[i+2]][0] = s->current_picture.motion_val[dir][s->block_index[i]][0];
                            s->mv[dir][i+2][1] = s->mv[dir][i][1] = s->current_picture.motion_val[dir][s->block_index[i+2]][1] = s->current_picture.motion_val[dir][s->block_index[i]][1];
                            s->mv[dir2][i+2][0] = s->mv[dir2][i][0] = s->current_picture.motion_val[dir2][s->block_index[i]][0] = s->current_picture.motion_val[dir2][s->block_index[i+2]][0];
                            s->mv[dir2][i+2][1] = s->mv[dir2][i][1] = s->current_picture.motion_val[dir2][s->block_index[i]][1] = s->current_picture.motion_val[dir2][s->block_index[i+2]][1];
                        }
                    } else {
                        v->blk_mv_type[s->block_index[0]] = 1;
                        v->blk_mv_type[s->block_index[1]] = 1;
                        v->blk_mv_type[s->block_index[2]] = 1;
                        v->blk_mv_type[s->block_index[3]] = 1;
                        vc1_pred_mv_intfr(v, 0, 0, 0, 2, v->range_x, v->range_y, 0, !dir);
                        for (i = 0; i < 2; i++) {
                            s->mv[!dir][i+2][0] = s->mv[!dir][i][0] = s->current_picture.motion_val[!dir][s->block_index[i+2]][0] = s->current_picture.motion_val[!dir][s->block_index[i]][0];
                            s->mv[!dir][i+2][1] = s->mv[!dir][i][1] = s->current_picture.motion_val[!dir][s->block_index[i+2]][1] = s->current_picture.motion_val[!dir][s->block_index[i]][1];
                        }
                    }
                }
            }

            vc1_mc_1mv(v, dir);
            if (direct || bmvtype == BMV_TYPE_INTERPOLATED) {
                vc1_interp_mc(v);
            }
        }
    }
    if (s->mb_x == s->mb_width - 1)
        memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
    v->cbp[s->mb_x]      = block_cbp;
    v->ttblk[s->mb_x]    = block_tt;
    return 0;
}

/** Decode blocks of I-frame
 */
static void vc1_decode_i_blocks(VC1Context *v)
{
    int k, j;
    MpegEncContext *s = &v->s;
    int cbp, val;
    uint8_t *coded_val;
    int mb_pos;

    /* select codingmode used for VLC tables selection */
    switch (v->y_ac_table_index) {
    case 0:
        v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
        break;
    case 1:
        v->codingset = CS_HIGH_MOT_INTRA;
        break;
    case 2:
        v->codingset = CS_MID_RATE_INTRA;
        break;
    }

    switch (v->c_ac_table_index) {
    case 0:
        v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
        break;
    case 1:
        v->codingset2 = CS_HIGH_MOT_INTER;
        break;
    case 2:
        v->codingset2 = CS_MID_RATE_INTER;
        break;
    }

    /* Set DC scale - y and c use the same */
    s->y_dc_scale = s->y_dc_scale_table[v->pq];
    s->c_dc_scale = s->c_dc_scale_table[v->pq];

    //do frame decode
    s->mb_x = s->mb_y = 0;
    s->mb_intra         = 1;
    s->first_slice_line = 1;
    for (s->mb_y = 0; s->mb_y < s->end_mb_y; s->mb_y++) {
        s->mb_x = 0;
        init_block_index(v);
        for (; s->mb_x < v->end_mb_x; s->mb_x++) {
            uint8_t *dst[6];
            ff_update_block_index(s);
            dst[0] = s->dest[0];
            dst[1] = dst[0] + 8;
            dst[2] = s->dest[0] + s->linesize * 8;
            dst[3] = dst[2] + 8;
            dst[4] = s->dest[1];
            dst[5] = s->dest[2];
            s->dsp.clear_blocks(s->block[0]);
            mb_pos = s->mb_x + s->mb_y * s->mb_width;
            s->current_picture.mb_type[mb_pos]                     = MB_TYPE_INTRA;
            s->current_picture.qscale_table[mb_pos]                = v->pq;
            s->current_picture.motion_val[1][s->block_index[0]][0] = 0;
            s->current_picture.motion_val[1][s->block_index[0]][1] = 0;

            // do actual MB decoding and displaying
            cbp = get_vlc2(&v->s.gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
            v->s.ac_pred = get_bits1(&v->s.gb);

            for (k = 0; k < 6; k++) {
                val = ((cbp >> (5 - k)) & 1);

                if (k < 4) {
                    int pred   = vc1_coded_block_pred(&v->s, k, &coded_val);
                    val        = val ^ pred;
                    *coded_val = val;
                }
                cbp |= val << (5 - k);

                vc1_decode_i_block(v, s->block[k], k, val, (k < 4) ? v->codingset : v->codingset2);

                if (k > 3 && (s->flags & CODEC_FLAG_GRAY))
                    continue;
                v->vc1dsp.vc1_inv_trans_8x8(s->block[k]);
                if (v->pq >= 9 && v->overlap) {
                    if (v->rangeredfrm)
                        for (j = 0; j < 64; j++)
                            s->block[k][j] <<= 1;
                    s->dsp.put_signed_pixels_clamped(s->block[k], dst[k], k & 4 ? s->uvlinesize : s->linesize);
                } else {
                    if (v->rangeredfrm)
                        for (j = 0; j < 64; j++)
                            s->block[k][j] = (s->block[k][j] - 64) << 1;
                    s->dsp.put_pixels_clamped(s->block[k], dst[k], k & 4 ? s->uvlinesize : s->linesize);
                }
            }

            if (v->pq >= 9 && v->overlap) {
                if (s->mb_x) {
                    v->vc1dsp.vc1_h_overlap(s->dest[0], s->linesize);
                    v->vc1dsp.vc1_h_overlap(s->dest[0] + 8 * s->linesize, s->linesize);
                    if (!(s->flags & CODEC_FLAG_GRAY)) {
                        v->vc1dsp.vc1_h_overlap(s->dest[1], s->uvlinesize);
                        v->vc1dsp.vc1_h_overlap(s->dest[2], s->uvlinesize);
                    }
                }
                v->vc1dsp.vc1_h_overlap(s->dest[0] + 8, s->linesize);
                v->vc1dsp.vc1_h_overlap(s->dest[0] + 8 * s->linesize + 8, s->linesize);
                if (!s->first_slice_line) {
                    v->vc1dsp.vc1_v_overlap(s->dest[0], s->linesize);
                    v->vc1dsp.vc1_v_overlap(s->dest[0] + 8, s->linesize);
                    if (!(s->flags & CODEC_FLAG_GRAY)) {
                        v->vc1dsp.vc1_v_overlap(s->dest[1], s->uvlinesize);
                        v->vc1dsp.vc1_v_overlap(s->dest[2], s->uvlinesize);
                    }
                }
                v->vc1dsp.vc1_v_overlap(s->dest[0] + 8 * s->linesize, s->linesize);
                v->vc1dsp.vc1_v_overlap(s->dest[0] + 8 * s->linesize + 8, s->linesize);
            }
            if (v->s.loop_filter) vc1_loop_filter_iblk(v, v->pq);

            if (get_bits_count(&s->gb) > v->bits) {
                ff_er_add_slice(&s->er, 0, 0, s->mb_x, s->mb_y, ER_MB_ERROR);
                av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i\n",
                       get_bits_count(&s->gb), v->bits);
                return;
            }
        }
        if (!v->s.loop_filter)
            ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
        else if (s->mb_y)
            ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);

        s->first_slice_line = 0;
    }
    if (v->s.loop_filter)
        ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);

    /* This is intentionally mb_height and not end_mb_y - unlike in advanced
     * profile, these only differ are when decoding MSS2 rectangles. */
    ff_er_add_slice(&s->er, 0, 0, s->mb_width - 1, s->mb_height - 1, ER_MB_END);
}

/** Decode blocks of I-frame for advanced profile
 */
static void vc1_decode_i_blocks_adv(VC1Context *v)
{
    int k;
    MpegEncContext *s = &v->s;
    int cbp, val;
    uint8_t *coded_val;
    int mb_pos;
    int mquant = v->pq;
    int mqdiff;
    GetBitContext *gb = &s->gb;

    /* select codingmode used for VLC tables selection */
    switch (v->y_ac_table_index) {
    case 0:
        v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
        break;
    case 1:
        v->codingset = CS_HIGH_MOT_INTRA;
        break;
    case 2:
        v->codingset = CS_MID_RATE_INTRA;
        break;
    }

    switch (v->c_ac_table_index) {
    case 0:
        v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
        break;
    case 1:
        v->codingset2 = CS_HIGH_MOT_INTER;
        break;
    case 2:
        v->codingset2 = CS_MID_RATE_INTER;
        break;
    }

    // do frame decode
    s->mb_x             = s->mb_y = 0;
    s->mb_intra         = 1;
    s->first_slice_line = 1;
    s->mb_y             = s->start_mb_y;
    if (s->start_mb_y) {
        s->mb_x = 0;
        init_block_index(v);
        memset(&s->coded_block[s->block_index[0] - s->b8_stride], 0,
               (1 + s->b8_stride) * sizeof(*s->coded_block));
    }
    for (; s->mb_y < s->end_mb_y; s->mb_y++) {
        s->mb_x = 0;
        init_block_index(v);
        for (;s->mb_x < s->mb_width; s->mb_x++) {
            int16_t (*block)[64] = v->block[v->cur_blk_idx];
            ff_update_block_index(s);
            s->dsp.clear_blocks(block[0]);
            mb_pos = s->mb_x + s->mb_y * s->mb_stride;
            s->current_picture.mb_type[mb_pos + v->mb_off]                         = MB_TYPE_INTRA;
            s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
            s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;

            // do actual MB decoding and displaying
            if (v->fieldtx_is_raw)
                v->fieldtx_plane[mb_pos] = get_bits1(&v->s.gb);
            cbp = get_vlc2(&v->s.gb, ff_msmp4_mb_i_vlc.table, MB_INTRA_VLC_BITS, 2);
            if ( v->acpred_is_raw)
                v->s.ac_pred = get_bits1(&v->s.gb);
            else
                v->s.ac_pred = v->acpred_plane[mb_pos];

            if (v->condover == CONDOVER_SELECT && v->overflg_is_raw)
                v->over_flags_plane[mb_pos] = get_bits1(&v->s.gb);

            GET_MQUANT();

            s->current_picture.qscale_table[mb_pos] = mquant;
            /* Set DC scale - y and c use the same */
            s->y_dc_scale = s->y_dc_scale_table[mquant];
            s->c_dc_scale = s->c_dc_scale_table[mquant];

            for (k = 0; k < 6; k++) {
                val = ((cbp >> (5 - k)) & 1);

                if (k < 4) {
                    int pred   = vc1_coded_block_pred(&v->s, k, &coded_val);
                    val        = val ^ pred;
                    *coded_val = val;
                }
                cbp |= val << (5 - k);

                v->a_avail = !s->first_slice_line || (k == 2 || k == 3);
                v->c_avail = !!s->mb_x || (k == 1 || k == 3);

                vc1_decode_i_block_adv(v, block[k], k, val,
                                       (k < 4) ? v->codingset : v->codingset2, mquant);

                if (k > 3 && (s->flags & CODEC_FLAG_GRAY))
                    continue;
                v->vc1dsp.vc1_inv_trans_8x8(block[k]);
            }

            vc1_smooth_overlap_filter_iblk(v);
            vc1_put_signed_blocks_clamped(v);
            if (v->s.loop_filter) vc1_loop_filter_iblk_delayed(v, v->pq);

            if (get_bits_count(&s->gb) > v->bits) {
                // TODO: may need modification to handle slice coding
                ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i\n",
                       get_bits_count(&s->gb), v->bits);
                return;
            }
        }
        if (!v->s.loop_filter)
            ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
        else if (s->mb_y)
            ff_mpeg_draw_horiz_band(s, (s->mb_y-1) * 16, 16);
        s->first_slice_line = 0;
    }

    /* raw bottom MB row */
    s->mb_x = 0;
    init_block_index(v);

    for (;s->mb_x < s->mb_width; s->mb_x++) {
        ff_update_block_index(s);
        vc1_put_signed_blocks_clamped(v);
        if (v->s.loop_filter)
            vc1_loop_filter_iblk_delayed(v, v->pq);
    }
    if (v->s.loop_filter)
        ff_mpeg_draw_horiz_band(s, (s->end_mb_y-1)*16, 16);
    ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                    (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
}

static void vc1_decode_p_blocks(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int apply_loop_filter;

    /* select codingmode used for VLC tables selection */
    switch (v->c_ac_table_index) {
    case 0:
        v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
        break;
    case 1:
        v->codingset = CS_HIGH_MOT_INTRA;
        break;
    case 2:
        v->codingset = CS_MID_RATE_INTRA;
        break;
    }

    switch (v->c_ac_table_index) {
    case 0:
        v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
        break;
    case 1:
        v->codingset2 = CS_HIGH_MOT_INTER;
        break;
    case 2:
        v->codingset2 = CS_MID_RATE_INTER;
        break;
    }

    apply_loop_filter   = s->loop_filter && !(s->avctx->skip_loop_filter >= AVDISCARD_NONKEY) &&
                          v->fcm == PROGRESSIVE;
    s->first_slice_line = 1;
    memset(v->cbp_base, 0, sizeof(v->cbp_base[0])*2*s->mb_stride);
    for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
        s->mb_x = 0;
        init_block_index(v);
        for (; s->mb_x < s->mb_width; s->mb_x++) {
            ff_update_block_index(s);

            if (v->fcm == ILACE_FIELD)
                vc1_decode_p_mb_intfi(v);
            else if (v->fcm == ILACE_FRAME)
                vc1_decode_p_mb_intfr(v);
            else vc1_decode_p_mb(v);
            if (s->mb_y != s->start_mb_y && apply_loop_filter)
                vc1_apply_p_loop_filter(v);
            if (get_bits_count(&s->gb) > v->bits || get_bits_count(&s->gb) < 0) {
                // TODO: may need modification to handle slice coding
                ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i at %ix%i\n",
                       get_bits_count(&s->gb), v->bits, s->mb_x, s->mb_y);
                return;
            }
        }
        memmove(v->cbp_base,      v->cbp,      sizeof(v->cbp_base[0])      * s->mb_stride);
        memmove(v->ttblk_base,    v->ttblk,    sizeof(v->ttblk_base[0])    * s->mb_stride);
        memmove(v->is_intra_base, v->is_intra, sizeof(v->is_intra_base[0]) * s->mb_stride);
        memmove(v->luma_mv_base,  v->luma_mv,  sizeof(v->luma_mv_base[0])  * s->mb_stride);
        if (s->mb_y != s->start_mb_y) ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);
        s->first_slice_line = 0;
    }
    if (apply_loop_filter) {
        s->mb_x = 0;
        init_block_index(v);
        for (; s->mb_x < s->mb_width; s->mb_x++) {
            ff_update_block_index(s);
            vc1_apply_p_loop_filter(v);
        }
    }
    if (s->end_mb_y >= s->start_mb_y)
        ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
    ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                    (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
}

static void vc1_decode_b_blocks(VC1Context *v)
{
    MpegEncContext *s = &v->s;

    /* select codingmode used for VLC tables selection */
    switch (v->c_ac_table_index) {
    case 0:
        v->codingset = (v->pqindex <= 8) ? CS_HIGH_RATE_INTRA : CS_LOW_MOT_INTRA;
        break;
    case 1:
        v->codingset = CS_HIGH_MOT_INTRA;
        break;
    case 2:
        v->codingset = CS_MID_RATE_INTRA;
        break;
    }

    switch (v->c_ac_table_index) {
    case 0:
        v->codingset2 = (v->pqindex <= 8) ? CS_HIGH_RATE_INTER : CS_LOW_MOT_INTER;
        break;
    case 1:
        v->codingset2 = CS_HIGH_MOT_INTER;
        break;
    case 2:
        v->codingset2 = CS_MID_RATE_INTER;
        break;
    }

    s->first_slice_line = 1;
    for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
        s->mb_x = 0;
        init_block_index(v);
        for (; s->mb_x < s->mb_width; s->mb_x++) {
            ff_update_block_index(s);

            if (v->fcm == ILACE_FIELD)
                vc1_decode_b_mb_intfi(v);
            else if (v->fcm == ILACE_FRAME)
                vc1_decode_b_mb_intfr(v);
            else
                vc1_decode_b_mb(v);
            if (get_bits_count(&s->gb) > v->bits || get_bits_count(&s->gb) < 0) {
                // TODO: may need modification to handle slice coding
                ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_x, s->mb_y, ER_MB_ERROR);
                av_log(s->avctx, AV_LOG_ERROR, "Bits overconsumption: %i > %i at %ix%i\n",
                       get_bits_count(&s->gb), v->bits, s->mb_x, s->mb_y);
                return;
            }
            if (v->s.loop_filter) vc1_loop_filter_iblk(v, v->pq);
        }
        if (!v->s.loop_filter)
            ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
        else if (s->mb_y)
            ff_mpeg_draw_horiz_band(s, (s->mb_y - 1) * 16, 16);
        s->first_slice_line = 0;
    }
    if (v->s.loop_filter)
        ff_mpeg_draw_horiz_band(s, (s->end_mb_y - 1) * 16, 16);
    ff_er_add_slice(&s->er, 0, s->start_mb_y << v->field_mode, s->mb_width - 1,
                    (s->end_mb_y << v->field_mode) - 1, ER_MB_END);
}

static void vc1_decode_skip_blocks(VC1Context *v)
{
    MpegEncContext *s = &v->s;

    if (!v->s.last_picture.f.data[0])
        return;

    ff_er_add_slice(&s->er, 0, s->start_mb_y, s->mb_width - 1, s->end_mb_y - 1, ER_MB_END);
    s->first_slice_line = 1;
    for (s->mb_y = s->start_mb_y; s->mb_y < s->end_mb_y; s->mb_y++) {
        s->mb_x = 0;
        init_block_index(v);
        ff_update_block_index(s);
        memcpy(s->dest[0], s->last_picture.f.data[0] + s->mb_y * 16 * s->linesize,   s->linesize   * 16);
        memcpy(s->dest[1], s->last_picture.f.data[1] + s->mb_y *  8 * s->uvlinesize, s->uvlinesize *  8);
        memcpy(s->dest[2], s->last_picture.f.data[2] + s->mb_y *  8 * s->uvlinesize, s->uvlinesize *  8);
        ff_mpeg_draw_horiz_band(s, s->mb_y * 16, 16);
        s->first_slice_line = 0;
    }
    s->pict_type = AV_PICTURE_TYPE_P;
}

void ff_vc1_decode_blocks(VC1Context *v)
{

    v->s.esc3_level_length = 0;
    if (v->x8_type) {
        ff_intrax8_decode_picture(&v->x8, 2*v->pq + v->halfpq, v->pq * !v->pquantizer);
    } else {
        v->cur_blk_idx     =  0;
        v->left_blk_idx    = -1;
        v->topleft_blk_idx =  1;
        v->top_blk_idx     =  2;
        switch (v->s.pict_type) {
        case AV_PICTURE_TYPE_I:
            if (v->profile == PROFILE_ADVANCED)
                vc1_decode_i_blocks_adv(v);
            else
                vc1_decode_i_blocks(v);
            break;
        case AV_PICTURE_TYPE_P:
            if (v->p_frame_skipped)
                vc1_decode_skip_blocks(v);
            else
                vc1_decode_p_blocks(v);
            break;
        case AV_PICTURE_TYPE_B:
            if (v->bi_type) {
                if (v->profile == PROFILE_ADVANCED)
                    vc1_decode_i_blocks_adv(v);
                else
                    vc1_decode_i_blocks(v);
            } else
                vc1_decode_b_blocks(v);
            break;
        }
    }
}

#if CONFIG_WMV3IMAGE_DECODER || CONFIG_VC1IMAGE_DECODER

typedef struct {
    /**
     * Transform coefficients for both sprites in 16.16 fixed point format,
     * in the order they appear in the bitstream:
     *  x scale
     *  rotation 1 (unused)
     *  x offset
     *  rotation 2 (unused)
     *  y scale
     *  y offset
     *  alpha
     */
    int coefs[2][7];

    int effect_type, effect_flag;
    int effect_pcount1, effect_pcount2;   ///< amount of effect parameters stored in effect_params
    int effect_params1[15], effect_params2[10]; ///< effect parameters in 16.16 fixed point format
} SpriteData;

static inline int get_fp_val(GetBitContext* gb)
{
    return (get_bits_long(gb, 30) - (1 << 29)) << 1;
}

static void vc1_sprite_parse_transform(GetBitContext* gb, int c[7])
{
    c[1] = c[3] = 0;

    switch (get_bits(gb, 2)) {
    case 0:
        c[0] = 1 << 16;
        c[2] = get_fp_val(gb);
        c[4] = 1 << 16;
        break;
    case 1:
        c[0] = c[4] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        break;
    case 2:
        c[0] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        c[4] = get_fp_val(gb);
        break;
    case 3:
        c[0] = get_fp_val(gb);
        c[1] = get_fp_val(gb);
        c[2] = get_fp_val(gb);
        c[3] = get_fp_val(gb);
        c[4] = get_fp_val(gb);
        break;
    }
    c[5] = get_fp_val(gb);
    if (get_bits1(gb))
        c[6] = get_fp_val(gb);
    else
        c[6] = 1 << 16;
}

static void vc1_parse_sprites(VC1Context *v, GetBitContext* gb, SpriteData* sd)
{
    AVCodecContext *avctx = v->s.avctx;
    int sprite, i;

    for (sprite = 0; sprite <= v->two_sprites; sprite++) {
        vc1_sprite_parse_transform(gb, sd->coefs[sprite]);
        if (sd->coefs[sprite][1] || sd->coefs[sprite][3])
            avpriv_request_sample(avctx, "Non-zero rotation coefficients");
        av_log(avctx, AV_LOG_DEBUG, sprite ? "S2:" : "S1:");
        for (i = 0; i < 7; i++)
            av_log(avctx, AV_LOG_DEBUG, " %d.%.3d",
                   sd->coefs[sprite][i] / (1<<16),
                   (abs(sd->coefs[sprite][i]) & 0xFFFF) * 1000 / (1 << 16));
        av_log(avctx, AV_LOG_DEBUG, "\n");
    }

    skip_bits(gb, 2);
    if (sd->effect_type = get_bits_long(gb, 30)) {
        switch (sd->effect_pcount1 = get_bits(gb, 4)) {
        case 7:
            vc1_sprite_parse_transform(gb, sd->effect_params1);
            break;
        case 14:
            vc1_sprite_parse_transform(gb, sd->effect_params1);
            vc1_sprite_parse_transform(gb, sd->effect_params1 + 7);
            break;
        default:
            for (i = 0; i < sd->effect_pcount1; i++)
                sd->effect_params1[i] = get_fp_val(gb);
        }
        if (sd->effect_type != 13 || sd->effect_params1[0] != sd->coefs[0][6]) {
            // effect 13 is simple alpha blending and matches the opacity above
            av_log(avctx, AV_LOG_DEBUG, "Effect: %d; params: ", sd->effect_type);
            for (i = 0; i < sd->effect_pcount1; i++)
                av_log(avctx, AV_LOG_DEBUG, " %d.%.2d",
                       sd->effect_params1[i] / (1 << 16),
                       (abs(sd->effect_params1[i]) & 0xFFFF) * 1000 / (1 << 16));
            av_log(avctx, AV_LOG_DEBUG, "\n");
        }

        sd->effect_pcount2 = get_bits(gb, 16);
        if (sd->effect_pcount2 > 10) {
            av_log(avctx, AV_LOG_ERROR, "Too many effect parameters\n");
            return;
        } else if (sd->effect_pcount2) {
            i = -1;
            av_log(avctx, AV_LOG_DEBUG, "Effect params 2: ");
            while (++i < sd->effect_pcount2) {
                sd->effect_params2[i] = get_fp_val(gb);
                av_log(avctx, AV_LOG_DEBUG, " %d.%.2d",
                       sd->effect_params2[i] / (1 << 16),
                       (abs(sd->effect_params2[i]) & 0xFFFF) * 1000 / (1 << 16));
            }
            av_log(avctx, AV_LOG_DEBUG, "\n");
        }
    }
    if (sd->effect_flag = get_bits1(gb))
        av_log(avctx, AV_LOG_DEBUG, "Effect flag set\n");

    if (get_bits_count(gb) >= gb->size_in_bits +
       (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE ? 64 : 0))
        av_log(avctx, AV_LOG_ERROR, "Buffer overrun\n");
    if (get_bits_count(gb) < gb->size_in_bits - 8)
        av_log(avctx, AV_LOG_WARNING, "Buffer not fully read\n");
}

static void vc1_draw_sprites(VC1Context *v, SpriteData* sd)
{
    int i, plane, row, sprite;
    int sr_cache[2][2] = { { -1, -1 }, { -1, -1 } };
    uint8_t* src_h[2][2];
    int xoff[2], xadv[2], yoff[2], yadv[2], alpha;
    int ysub[2];
    MpegEncContext *s = &v->s;

    for (i = 0; i < 2; i++) {
        xoff[i] = av_clip(sd->coefs[i][2], 0, v->sprite_width-1 << 16);
        xadv[i] = sd->coefs[i][0];
        if (xadv[i] != 1<<16 || (v->sprite_width << 16) - (v->output_width << 16) - xoff[i])
            xadv[i] = av_clip(xadv[i], 0, ((v->sprite_width<<16) - xoff[i] - 1) / v->output_width);

        yoff[i] = av_clip(sd->coefs[i][5], 0, v->sprite_height-1 << 16);
        yadv[i] = av_clip(sd->coefs[i][4], 0, ((v->sprite_height << 16) - yoff[i]) / v->output_height);
    }
    alpha = av_clip(sd->coefs[1][6], 0, (1<<16) - 1);

    for (plane = 0; plane < (s->flags&CODEC_FLAG_GRAY ? 1 : 3); plane++) {
        int width = v->output_width>>!!plane;

        for (row = 0; row < v->output_height>>!!plane; row++) {
            uint8_t *dst = v->sprite_output_frame.data[plane] +
                           v->sprite_output_frame.linesize[plane] * row;

            for (sprite = 0; sprite <= v->two_sprites; sprite++) {
                uint8_t *iplane = s->current_picture.f.data[plane];
                int      iline  = s->current_picture.f.linesize[plane];
                int      ycoord = yoff[sprite] + yadv[sprite] * row;
                int      yline  = ycoord >> 16;
                int      next_line;
                ysub[sprite] = ycoord & 0xFFFF;
                if (sprite) {
                    iplane = s->last_picture.f.data[plane];
                    iline  = s->last_picture.f.linesize[plane];
                }
                next_line = FFMIN(yline + 1, (v->sprite_height >> !!plane) - 1) * iline;
                if (!(xoff[sprite] & 0xFFFF) && xadv[sprite] == 1 << 16) {
                        src_h[sprite][0] = iplane + (xoff[sprite] >> 16) +  yline      * iline;
                    if (ysub[sprite])
                        src_h[sprite][1] = iplane + (xoff[sprite] >> 16) + next_line;
                } else {
                    if (sr_cache[sprite][0] != yline) {
                        if (sr_cache[sprite][1] == yline) {
                            FFSWAP(uint8_t*, v->sr_rows[sprite][0], v->sr_rows[sprite][1]);
                            FFSWAP(int,        sr_cache[sprite][0],   sr_cache[sprite][1]);
                        } else {
                            v->vc1dsp.sprite_h(v->sr_rows[sprite][0], iplane + yline * iline, xoff[sprite], xadv[sprite], width);
                            sr_cache[sprite][0] = yline;
                        }
                    }
                    if (ysub[sprite] && sr_cache[sprite][1] != yline + 1) {
                        v->vc1dsp.sprite_h(v->sr_rows[sprite][1],
                                           iplane + next_line, xoff[sprite],
                                           xadv[sprite], width);
                        sr_cache[sprite][1] = yline + 1;
                    }
                    src_h[sprite][0] = v->sr_rows[sprite][0];
                    src_h[sprite][1] = v->sr_rows[sprite][1];
                }
            }

            if (!v->two_sprites) {
                if (ysub[0]) {
                    v->vc1dsp.sprite_v_single(dst, src_h[0][0], src_h[0][1], ysub[0], width);
                } else {
                    memcpy(dst, src_h[0][0], width);
                }
            } else {
                if (ysub[0] && ysub[1]) {
                    v->vc1dsp.sprite_v_double_twoscale(dst, src_h[0][0], src_h[0][1], ysub[0],
                                                       src_h[1][0], src_h[1][1], ysub[1], alpha, width);
                } else if (ysub[0]) {
                    v->vc1dsp.sprite_v_double_onescale(dst, src_h[0][0], src_h[0][1], ysub[0],
                                                       src_h[1][0], alpha, width);
                } else if (ysub[1]) {
                    v->vc1dsp.sprite_v_double_onescale(dst, src_h[1][0], src_h[1][1], ysub[1],
                                                       src_h[0][0], (1<<16)-1-alpha, width);
                } else {
                    v->vc1dsp.sprite_v_double_noscale(dst, src_h[0][0], src_h[1][0], alpha, width);
                }
            }
        }

        if (!plane) {
            for (i = 0; i < 2; i++) {
                xoff[i] >>= 1;
                yoff[i] >>= 1;
            }
        }

    }
}


static int vc1_decode_sprites(VC1Context *v, GetBitContext* gb)
{
    int ret;
    MpegEncContext *s     = &v->s;
    AVCodecContext *avctx = s->avctx;
    SpriteData sd;

    vc1_parse_sprites(v, gb, &sd);

    if (!s->current_picture.f.data[0]) {
        av_log(avctx, AV_LOG_ERROR, "Got no sprites\n");
        return -1;
    }

    if (v->two_sprites && (!s->last_picture_ptr || !s->last_picture.f.data[0])) {
        av_log(avctx, AV_LOG_WARNING, "Need two sprites, only got one\n");
        v->two_sprites = 0;
    }

    av_frame_unref(&v->sprite_output_frame);
    if ((ret = ff_get_buffer(avctx, &v->sprite_output_frame, 0)) < 0)
        return ret;

    vc1_draw_sprites(v, &sd);

    return 0;
}

static void vc1_sprite_flush(AVCodecContext *avctx)
{
    VC1Context *v     = avctx->priv_data;
    MpegEncContext *s = &v->s;
    AVFrame *f = &s->current_picture.f;
    int plane, i;

    /* Windows Media Image codecs have a convergence interval of two keyframes.
       Since we can't enforce it, clear to black the missing sprite. This is
       wrong but it looks better than doing nothing. */

    if (f->data[0])
        for (plane = 0; plane < (s->flags&CODEC_FLAG_GRAY ? 1 : 3); plane++)
            for (i = 0; i < v->sprite_height>>!!plane; i++)
                memset(f->data[plane] + i * f->linesize[plane],
                       plane ? 128 : 0, f->linesize[plane]);
}

#endif

av_cold int ff_vc1_decode_init_alloc_tables(VC1Context *v)
{
    MpegEncContext *s = &v->s;
    int i;

    /* Allocate mb bitplanes */
    v->mv_type_mb_plane = av_malloc (s->mb_stride * s->mb_height);
    v->direct_mb_plane  = av_malloc (s->mb_stride * s->mb_height);
    v->forward_mb_plane = av_malloc (s->mb_stride * s->mb_height);
    v->fieldtx_plane    = av_mallocz(s->mb_stride * s->mb_height);
    v->acpred_plane     = av_malloc (s->mb_stride * s->mb_height);
    v->over_flags_plane = av_malloc (s->mb_stride * s->mb_height);

    v->n_allocated_blks = s->mb_width + 2;
    v->block            = av_malloc(sizeof(*v->block) * v->n_allocated_blks);
    v->cbp_base         = av_malloc(sizeof(v->cbp_base[0]) * 2 * s->mb_stride);
    v->cbp              = v->cbp_base + s->mb_stride;
    v->ttblk_base       = av_malloc(sizeof(v->ttblk_base[0]) * 2 * s->mb_stride);
    v->ttblk            = v->ttblk_base + s->mb_stride;
    v->is_intra_base    = av_mallocz(sizeof(v->is_intra_base[0]) * 2 * s->mb_stride);
    v->is_intra         = v->is_intra_base + s->mb_stride;
    v->luma_mv_base     = av_malloc(sizeof(v->luma_mv_base[0]) * 2 * s->mb_stride);
    v->luma_mv          = v->luma_mv_base + s->mb_stride;

    /* allocate block type info in that way so it could be used with s->block_index[] */
    v->mb_type_base = av_malloc(s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2);
    v->mb_type[0]   = v->mb_type_base + s->b8_stride + 1;
    v->mb_type[1]   = v->mb_type_base + s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride + 1;
    v->mb_type[2]   = v->mb_type[1] + s->mb_stride * (s->mb_height + 1);

    /* allocate memory to store block level MV info */
    v->blk_mv_type_base = av_mallocz(     s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2);
    v->blk_mv_type      = v->blk_mv_type_base + s->b8_stride + 1;
    v->mv_f_base        = av_mallocz(2 * (s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2));
    v->mv_f[0]          = v->mv_f_base + s->b8_stride + 1;
    v->mv_f[1]          = v->mv_f[0] + (s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2);
    v->mv_f_next_base   = av_mallocz(2 * (s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2));
    v->mv_f_next[0]     = v->mv_f_next_base + s->b8_stride + 1;
    v->mv_f_next[1]     = v->mv_f_next[0] + (s->b8_stride * (s->mb_height * 2 + 1) + s->mb_stride * (s->mb_height + 1) * 2);

    /* Init coded blocks info */
    if (v->profile == PROFILE_ADVANCED) {
//        if (alloc_bitplane(&v->over_flags_plane, s->mb_width, s->mb_height) < 0)
//            return -1;
//        if (alloc_bitplane(&v->ac_pred_plane, s->mb_width, s->mb_height) < 0)
//            return -1;
    }

    ff_intrax8_common_init(&v->x8,s);

    if (s->avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || s->avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        for (i = 0; i < 4; i++)
            if (!(v->sr_rows[i >> 1][i & 1] = av_malloc(v->output_width)))
                return AVERROR(ENOMEM);
    }

    if (!v->mv_type_mb_plane || !v->direct_mb_plane || !v->acpred_plane || !v->over_flags_plane ||
        !v->block || !v->cbp_base || !v->ttblk_base || !v->is_intra_base || !v->luma_mv_base ||
        !v->mb_type_base) {
        av_freep(&v->mv_type_mb_plane);
        av_freep(&v->direct_mb_plane);
        av_freep(&v->acpred_plane);
        av_freep(&v->over_flags_plane);
        av_freep(&v->block);
        av_freep(&v->cbp_base);
        av_freep(&v->ttblk_base);
        av_freep(&v->is_intra_base);
        av_freep(&v->luma_mv_base);
        av_freep(&v->mb_type_base);
        return AVERROR(ENOMEM);
    }

    return 0;
}

av_cold void ff_vc1_init_transposed_scantables(VC1Context *v)
{
    int i;
    for (i = 0; i < 64; i++) {
#define transpose(x) ((x >> 3) | ((x & 7) << 3))
        v->zz_8x8[0][i] = transpose(ff_wmv1_scantable[0][i]);
        v->zz_8x8[1][i] = transpose(ff_wmv1_scantable[1][i]);
        v->zz_8x8[2][i] = transpose(ff_wmv1_scantable[2][i]);
        v->zz_8x8[3][i] = transpose(ff_wmv1_scantable[3][i]);
        v->zzi_8x8[i]   = transpose(ff_vc1_adv_interlaced_8x8_zz[i]);
    }
    v->left_blk_sh = 0;
    v->top_blk_sh  = 3;
}

/** Initialize a VC1/WMV3 decoder
 * @todo TODO: Handle VC-1 IDUs (Transport level?)
 * @todo TODO: Decypher remaining bits in extra_data
 */
static av_cold int vc1_decode_init(AVCodecContext *avctx)
{
    VC1Context *v = avctx->priv_data;
    MpegEncContext *s = &v->s;
    GetBitContext gb;
    int ret;

    /* save the container output size for WMImage */
    v->output_width  = avctx->width;
    v->output_height = avctx->height;

    if (!avctx->extradata_size || !avctx->extradata)
        return -1;
    if (!(avctx->flags & CODEC_FLAG_GRAY))
        avctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
    else
        avctx->pix_fmt = AV_PIX_FMT_GRAY8;
    avctx->hwaccel = ff_find_hwaccel(avctx->codec->id, avctx->pix_fmt);
    v->s.avctx = avctx;
    avctx->flags |= CODEC_FLAG_EMU_EDGE;
    v->s.flags   |= CODEC_FLAG_EMU_EDGE;

    if ((ret = ff_vc1_init_common(v)) < 0)
        return ret;
    // ensure static VLC tables are initialized
    if ((ret = ff_msmpeg4_decode_init(avctx)) < 0)
        return ret;
    if ((ret = ff_vc1_decode_init_alloc_tables(v)) < 0)
        return ret;
    // Hack to ensure the above functions will be called
    // again once we know all necessary settings.
    // That this is necessary might indicate a bug.
    ff_vc1_decode_end(avctx);

    ff_h264chroma_init(&v->h264chroma, 8);
    ff_vc1dsp_init(&v->vc1dsp);

    if (avctx->codec_id == AV_CODEC_ID_WMV3 || avctx->codec_id == AV_CODEC_ID_WMV3IMAGE) {
        int count = 0;

        // looks like WMV3 has a sequence header stored in the extradata
        // advanced sequence header may be before the first frame
        // the last byte of the extradata is a version number, 1 for the
        // samples we can decode

        init_get_bits(&gb, avctx->extradata, avctx->extradata_size*8);

        if ((ret = ff_vc1_decode_sequence_header(avctx, v, &gb)) < 0)
          return ret;

        count = avctx->extradata_size*8 - get_bits_count(&gb);
        if (count > 0) {
            av_log(avctx, AV_LOG_INFO, "Extra data: %i bits left, value: %X\n",
                   count, get_bits(&gb, count));
        } else if (count < 0) {
            av_log(avctx, AV_LOG_INFO, "Read %i bits in overflow\n", -count);
        }
    } else { // VC1/WVC1/WVP2
        const uint8_t *start = avctx->extradata;
        uint8_t *end = avctx->extradata + avctx->extradata_size;
        const uint8_t *next;
        int size, buf2_size;
        uint8_t *buf2 = NULL;
        int seq_initialized = 0, ep_initialized = 0;

        if (avctx->extradata_size < 16) {
            av_log(avctx, AV_LOG_ERROR, "Extradata size too small: %i\n", avctx->extradata_size);
            return -1;
        }

        buf2  = av_mallocz(avctx->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
        start = find_next_marker(start, end); // in WVC1 extradata first byte is its size, but can be 0 in mkv
        next  = start;
        for (; next < end; start = next) {
            next = find_next_marker(start + 4, end);
            size = next - start - 4;
            if (size <= 0)
                continue;
            buf2_size = vc1_unescape_buffer(start + 4, size, buf2);
            init_get_bits(&gb, buf2, buf2_size * 8);
            switch (AV_RB32(start)) {
            case VC1_CODE_SEQHDR:
                if ((ret = ff_vc1_decode_sequence_header(avctx, v, &gb)) < 0) {
                    av_free(buf2);
                    return ret;
                }
                seq_initialized = 1;
                break;
            case VC1_CODE_ENTRYPOINT:
                if ((ret = ff_vc1_decode_entry_point(avctx, v, &gb)) < 0) {
                    av_free(buf2);
                    return ret;
                }
                ep_initialized = 1;
                break;
            }
        }
        av_free(buf2);
        if (!seq_initialized || !ep_initialized) {
            av_log(avctx, AV_LOG_ERROR, "Incomplete extradata\n");
            return -1;
        }
        v->res_sprite = (avctx->codec_id == AV_CODEC_ID_VC1IMAGE);
    }

    avctx->profile = v->profile;
    if (v->profile == PROFILE_ADVANCED)
        avctx->level = v->level;

    avctx->has_b_frames = !!avctx->max_b_frames;

    s->mb_width  = (avctx->coded_width  + 15) >> 4;
    s->mb_height = (avctx->coded_height + 15) >> 4;

    if (v->profile == PROFILE_ADVANCED || v->res_fasttx) {
        ff_vc1_init_transposed_scantables(v);
    } else {
        memcpy(v->zz_8x8, ff_wmv1_scantable, 4*64);
        v->left_blk_sh = 3;
        v->top_blk_sh  = 0;
    }

    if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        v->sprite_width  = avctx->coded_width;
        v->sprite_height = avctx->coded_height;

        avctx->coded_width  = avctx->width  = v->output_width;
        avctx->coded_height = avctx->height = v->output_height;

        // prevent 16.16 overflows
        if (v->sprite_width  > 1 << 14 ||
            v->sprite_height > 1 << 14 ||
            v->output_width  > 1 << 14 ||
            v->output_height > 1 << 14) return -1;

        if ((v->sprite_width&1) || (v->sprite_height&1)) {
            avpriv_request_sample(avctx, "odd sprites support");
            return AVERROR_PATCHWELCOME;
        }
    }
    return 0;
}

/** Close a VC1/WMV3 decoder
 * @warning Initial try at using MpegEncContext stuff
 */
av_cold int ff_vc1_decode_end(AVCodecContext *avctx)
{
    VC1Context *v = avctx->priv_data;
    int i;

    av_frame_unref(&v->sprite_output_frame);

    for (i = 0; i < 4; i++)
        av_freep(&v->sr_rows[i >> 1][i & 1]);
    av_freep(&v->hrd_rate);
    av_freep(&v->hrd_buffer);
    ff_MPV_common_end(&v->s);
    av_freep(&v->mv_type_mb_plane);
    av_freep(&v->direct_mb_plane);
    av_freep(&v->forward_mb_plane);
    av_freep(&v->fieldtx_plane);
    av_freep(&v->acpred_plane);
    av_freep(&v->over_flags_plane);
    av_freep(&v->mb_type_base);
    av_freep(&v->blk_mv_type_base);
    av_freep(&v->mv_f_base);
    av_freep(&v->mv_f_next_base);
    av_freep(&v->block);
    av_freep(&v->cbp_base);
    av_freep(&v->ttblk_base);
    av_freep(&v->is_intra_base); // FIXME use v->mb_type[]
    av_freep(&v->luma_mv_base);
    ff_intrax8_common_end(&v->x8);
    return 0;
}


/** Decode a VC1/WMV3 frame
 * @todo TODO: Handle VC-1 IDUs (Transport level?)
 */
static int vc1_decode_frame(AVCodecContext *avctx, void *data,
                            int *got_frame, AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size, n_slices = 0, i, ret;
    VC1Context *v = avctx->priv_data;
    MpegEncContext *s = &v->s;
    AVFrame *pict = data;
    uint8_t *buf2 = NULL;
    const uint8_t *buf_start = buf, *buf_start_second_field = NULL;
    int mb_height, n_slices1=-1;
    struct {
        uint8_t *buf;
        GetBitContext gb;
        int mby_start;
    } *slices = NULL, *tmp;

    v->second_field = 0;

    if(s->flags & CODEC_FLAG_LOW_DELAY)
        s->low_delay = 1;

    /* no supplementary picture */
    if (buf_size == 0 || (buf_size == 4 && AV_RB32(buf) == VC1_CODE_ENDOFSEQ)) {
        /* special case for last picture */
        if (s->low_delay == 0 && s->next_picture_ptr) {
            if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)
                return ret;
            s->next_picture_ptr = NULL;

            *got_frame = 1;
        }

        return buf_size;
    }

    if (s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
        if (v->profile < PROFILE_ADVANCED)
            avctx->pix_fmt = AV_PIX_FMT_VDPAU_WMV3;
        else
            avctx->pix_fmt = AV_PIX_FMT_VDPAU_VC1;
    }

    //for advanced profile we may need to parse and unescape data
    if (avctx->codec_id == AV_CODEC_ID_VC1 || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
        int buf_size2 = 0;
        buf2 = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
        if (!buf2)
            return AVERROR(ENOMEM);

        if (IS_MARKER(AV_RB32(buf))) { /* frame starts with marker and needs to be parsed */
            const uint8_t *start, *end, *next;
            int size;

            next = buf;
            for (start = buf, end = buf + buf_size; next < end; start = next) {
                next = find_next_marker(start + 4, end);
                size = next - start - 4;
                if (size <= 0) continue;
                switch (AV_RB32(start)) {
                case VC1_CODE_FRAME:
                    if (avctx->hwaccel ||
                        s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                        buf_start = start;
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    break;
                case VC1_CODE_FIELD: {
                    int buf_size3;
                    if (avctx->hwaccel ||
                        s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                        buf_start_second_field = start;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                        goto err;
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                        goto err;
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    /* assuming that the field marker is at the exact middle,
                       hope it's correct */
                    slices[n_slices].mby_start = s->mb_height >> 1;
                    n_slices1 = n_slices - 1; // index of the last slice of the first field
                    n_slices++;
                    break;
                }
                case VC1_CODE_ENTRYPOINT: /* it should be before frame data */
                    buf_size2 = vc1_unescape_buffer(start + 4, size, buf2);
                    init_get_bits(&s->gb, buf2, buf_size2 * 8);
                    ff_vc1_decode_entry_point(avctx, v, &s->gb);
                    break;
                case VC1_CODE_SLICE: {
                    int buf_size3;
                    tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                    if (!tmp)
                        goto err;
                    slices = tmp;
                    slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                    if (!slices[n_slices].buf)
                        goto err;
                    buf_size3 = vc1_unescape_buffer(start + 4, size,
                                                    slices[n_slices].buf);
                    init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                                  buf_size3 << 3);
                    slices[n_slices].mby_start = get_bits(&slices[n_slices].gb, 9);
                    n_slices++;
                    break;
                }
                }
            }
        } else if (v->interlace && ((buf[0] & 0xC0) == 0xC0)) { /* WVC1 interlaced stores both fields divided by marker */
            const uint8_t *divider;
            int buf_size3;

            divider = find_next_marker(buf, buf + buf_size);
            if ((divider == (buf + buf_size)) || AV_RB32(divider) != VC1_CODE_FIELD) {
                av_log(avctx, AV_LOG_ERROR, "Error in WVC1 interlaced frame\n");
                goto err;
            } else { // found field marker, unescape second field
                if (avctx->hwaccel ||
                    s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU)
                    buf_start_second_field = divider;
                tmp = av_realloc(slices, sizeof(*slices) * (n_slices+1));
                if (!tmp)
                    goto err;
                slices = tmp;
                slices[n_slices].buf = av_mallocz(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
                if (!slices[n_slices].buf)
                    goto err;
                buf_size3 = vc1_unescape_buffer(divider + 4, buf + buf_size - divider - 4, slices[n_slices].buf);
                init_get_bits(&slices[n_slices].gb, slices[n_slices].buf,
                              buf_size3 << 3);
                slices[n_slices].mby_start = s->mb_height >> 1;
                n_slices1 = n_slices - 1;
                n_slices++;
            }
            buf_size2 = vc1_unescape_buffer(buf, divider - buf, buf2);
        } else {
            buf_size2 = vc1_unescape_buffer(buf, buf_size, buf2);
        }
        init_get_bits(&s->gb, buf2, buf_size2*8);
    } else
        init_get_bits(&s->gb, buf, buf_size*8);

    if (v->res_sprite) {
        v->new_sprite  = !get_bits1(&s->gb);
        v->two_sprites =  get_bits1(&s->gb);
        /* res_sprite means a Windows Media Image stream, AV_CODEC_ID_*IMAGE means
           we're using the sprite compositor. These are intentionally kept separate
           so you can get the raw sprites by using the wmv3 decoder for WMVP or
           the vc1 one for WVP2 */
        if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
            if (v->new_sprite) {
                // switch AVCodecContext parameters to those of the sprites
                avctx->width  = avctx->coded_width  = v->sprite_width;
                avctx->height = avctx->coded_height = v->sprite_height;
            } else {
                goto image;
            }
        }
    }

    if (s->context_initialized &&
        (s->width  != avctx->coded_width ||
         s->height != avctx->coded_height)) {
        ff_vc1_decode_end(avctx);
    }

    if (!s->context_initialized) {
        if (ff_msmpeg4_decode_init(avctx) < 0)
            goto err;
        if (ff_vc1_decode_init_alloc_tables(v) < 0) {
            ff_MPV_common_end(s);
            goto err;
        }

        s->low_delay = !avctx->has_b_frames || v->res_sprite;

        if (v->profile == PROFILE_ADVANCED) {
            if(avctx->coded_width<=1 || avctx->coded_height<=1)
                goto err;
            s->h_edge_pos = avctx->coded_width;
            s->v_edge_pos = avctx->coded_height;
        }
    }

    /* We need to set current_picture_ptr before reading the header,
     * otherwise we cannot store anything in there. */
    if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {
        int i = ff_find_unused_picture(s, 0);
        if (i < 0)
            goto err;
        s->current_picture_ptr = &s->picture[i];
    }

    // do parse frame header
    v->pic_header_flag = 0;
    v->first_pic_header_flag = 1;
    if (v->profile < PROFILE_ADVANCED) {
        if (ff_vc1_parse_frame_header(v, &s->gb) < 0) {
            goto err;
        }
    } else {
        if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
            goto err;
        }
    }
    v->first_pic_header_flag = 0;

    if (avctx->debug & FF_DEBUG_PICT_INFO)
        av_log(v->s.avctx, AV_LOG_DEBUG, "pict_type: %c\n", av_get_picture_type_char(s->pict_type));

    if ((avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE)
        && s->pict_type != AV_PICTURE_TYPE_I) {
        av_log(v->s.avctx, AV_LOG_ERROR, "Sprite decoder: expected I-frame\n");
        goto err;
    }

    if ((s->mb_height >> v->field_mode) == 0) {
        av_log(v->s.avctx, AV_LOG_ERROR, "image too short\n");
        goto err;
    }

    // process pulldown flags
    s->current_picture_ptr->f.repeat_pict = 0;
    // Pulldown flags are only valid when 'broadcast' has been set.
    // So ticks_per_frame will be 2
    if (v->rff) {
        // repeat field
        s->current_picture_ptr->f.repeat_pict = 1;
    } else if (v->rptfrm) {
        // repeat frames
        s->current_picture_ptr->f.repeat_pict = v->rptfrm * 2;
    }

    // for skipping the frame
    s->current_picture.f.pict_type = s->pict_type;
    s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;

    /* skip B-frames if we don't have reference frames */
    if (s->last_picture_ptr == NULL && (s->pict_type == AV_PICTURE_TYPE_B || s->droppable)) {
        goto err;
    }
    if ((avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type == AV_PICTURE_TYPE_B) ||
        (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) ||
         avctx->skip_frame >= AVDISCARD_ALL) {
        goto end;
    }

    if (s->next_p_frame_damaged) {
        if (s->pict_type == AV_PICTURE_TYPE_B)
            goto end;
        else
            s->next_p_frame_damaged = 0;
    }

    if (ff_MPV_frame_start(s, avctx) < 0) {
        goto err;
    }

    v->s.current_picture_ptr->f.interlaced_frame = (v->fcm != PROGRESSIVE);
    v->s.current_picture_ptr->f.top_field_first  = v->tff;

    s->me.qpel_put = s->dsp.put_qpel_pixels_tab;
    s->me.qpel_avg = s->dsp.avg_qpel_pixels_tab;

    if ((CONFIG_VC1_VDPAU_DECODER)
        &&s->avctx->codec->capabilities&CODEC_CAP_HWACCEL_VDPAU) {
        if (v->field_mode && buf_start_second_field) {
            ff_vdpau_vc1_decode_picture(s, buf_start, buf_start_second_field - buf_start);
            ff_vdpau_vc1_decode_picture(s, buf_start_second_field, (buf + buf_size) - buf_start_second_field);
        } else {
            ff_vdpau_vc1_decode_picture(s, buf_start, (buf + buf_size) - buf_start);
        }
    } else if (avctx->hwaccel) {
        if (v->field_mode && buf_start_second_field) {
            // decode first field
            s->picture_structure = PICT_BOTTOM_FIELD - v->tff;
            if (avctx->hwaccel->start_frame(avctx, buf_start, buf_start_second_field - buf_start) < 0)
                goto err;
            if (avctx->hwaccel->decode_slice(avctx, buf_start, buf_start_second_field - buf_start) < 0)
                goto err;
            if (avctx->hwaccel->end_frame(avctx) < 0)
                goto err;

            // decode second field
            s->gb = slices[n_slices1 + 1].gb;
            s->picture_structure = PICT_TOP_FIELD + v->tff;
            v->second_field = 1;
            v->pic_header_flag = 0;
            if (ff_vc1_parse_frame_header_adv(v, &s->gb) < 0) {
                av_log(avctx, AV_LOG_ERROR, "parsing header for second field failed");
                goto err;
            }
            v->s.current_picture_ptr->f.pict_type = v->s.pict_type;

            if (avctx->hwaccel->start_frame(avctx, buf_start_second_field, (buf + buf_size) - buf_start_second_field) < 0)
                goto err;
            if (avctx->hwaccel->decode_slice(avctx, buf_start_second_field, (buf + buf_size) - buf_start_second_field) < 0)
                goto err;
            if (avctx->hwaccel->end_frame(avctx) < 0)
                goto err;
        } else {
            s->picture_structure = PICT_FRAME;
            if (avctx->hwaccel->start_frame(avctx, buf_start, (buf + buf_size) - buf_start) < 0)
                goto err;
            if (avctx->hwaccel->decode_slice(avctx, buf_start, (buf + buf_size) - buf_start) < 0)
                goto err;
            if (avctx->hwaccel->end_frame(avctx) < 0)
                goto err;
        }
    } else {
        int header_ret = 0;

        ff_mpeg_er_frame_start(s);

        v->bits = buf_size * 8;
        v->end_mb_x = s->mb_width;
        if (v->field_mode) {
            s->current_picture.f.linesize[0] <<= 1;
            s->current_picture.f.linesize[1] <<= 1;
            s->current_picture.f.linesize[2] <<= 1;
            s->linesize                      <<= 1;
            s->uvlinesize                    <<= 1;
        }
        mb_height = s->mb_height >> v->field_mode;

        av_assert0 (mb_height > 0);

        for (i = 0; i <= n_slices; i++) {
            if (i > 0 &&  slices[i - 1].mby_start >= mb_height) {
                if (v->field_mode <= 0) {
                    av_log(v->s.avctx, AV_LOG_ERROR, "Slice %d starts beyond "
                           "picture boundary (%d >= %d)\n", i,
                           slices[i - 1].mby_start, mb_height);
                    continue;
                }
                v->second_field = 1;
                v->blocks_off   = s->b8_stride * (s->mb_height&~1);
                v->mb_off       = s->mb_stride * s->mb_height >> 1;
            } else {
                v->second_field = 0;
                v->blocks_off   = 0;
                v->mb_off       = 0;
            }
            if (i) {
                v->pic_header_flag = 0;
                if (v->field_mode && i == n_slices1 + 2) {
                    if ((header_ret = ff_vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Field header damaged\n");
                        if (avctx->err_recognition & AV_EF_EXPLODE)
                            goto err;
                        continue;
                    }
                } else if (get_bits1(&s->gb)) {
                    v->pic_header_flag = 1;
                    if ((header_ret = ff_vc1_parse_frame_header_adv(v, &s->gb)) < 0) {
                        av_log(v->s.avctx, AV_LOG_ERROR, "Slice header damaged\n");
                        if (avctx->err_recognition & AV_EF_EXPLODE)
                            goto err;
                        continue;
                    }
                }
            }
            if (header_ret < 0)
                continue;
            s->start_mb_y = (i == 0) ? 0 : FFMAX(0, slices[i-1].mby_start % mb_height);
            if (!v->field_mode || v->second_field)
                s->end_mb_y = (i == n_slices     ) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            else {
                if (i >= n_slices) {
                    av_log(v->s.avctx, AV_LOG_ERROR, "first field slice count too large\n");
                    continue;
                }
                s->end_mb_y = (i <= n_slices1 + 1) ? mb_height : FFMIN(mb_height, slices[i].mby_start % mb_height);
            }
            if (s->end_mb_y <= s->start_mb_y) {
                av_log(v->s.avctx, AV_LOG_ERROR, "end mb y %d %d invalid\n", s->end_mb_y, s->start_mb_y);
                continue;
            }
            if (!v->p_frame_skipped && s->pict_type != AV_PICTURE_TYPE_I && !v->cbpcy_vlc) {
                av_log(v->s.avctx, AV_LOG_ERROR, "missing cbpcy_vlc\n");
                continue;
            }
            ff_vc1_decode_blocks(v);
            if (i != n_slices)
                s->gb = slices[i].gb;
        }
        if (v->field_mode) {
            v->second_field = 0;
            s->current_picture.f.linesize[0] >>= 1;
            s->current_picture.f.linesize[1] >>= 1;
            s->current_picture.f.linesize[2] >>= 1;
            s->linesize                      >>= 1;
            s->uvlinesize                    >>= 1;
            if (v->s.pict_type != AV_PICTURE_TYPE_BI && v->s.pict_type != AV_PICTURE_TYPE_B) {
                FFSWAP(uint8_t *, v->mv_f_next[0], v->mv_f[0]);
                FFSWAP(uint8_t *, v->mv_f_next[1], v->mv_f[1]);
            }
        }
        av_dlog(s->avctx, "Consumed %i/%i bits\n",
                get_bits_count(&s->gb), s->gb.size_in_bits);
//  if (get_bits_count(&s->gb) > buf_size * 8)
//      return -1;
        if(s->er.error_occurred && s->pict_type == AV_PICTURE_TYPE_B)
            goto err;
        if (!v->field_mode)
            ff_er_frame_end(&s->er);
    }

    ff_MPV_frame_end(s);

    if (avctx->codec_id == AV_CODEC_ID_WMV3IMAGE || avctx->codec_id == AV_CODEC_ID_VC1IMAGE) {
image:
        avctx->width  = avctx->coded_width  = v->output_width;
        avctx->height = avctx->coded_height = v->output_height;
        if (avctx->skip_frame >= AVDISCARD_NONREF)
            goto end;
#if CONFIG_WMV3IMAGE_DECODER || CONFIG_VC1IMAGE_DECODER
        if (vc1_decode_sprites(v, &s->gb))
            goto err;
#endif
        if ((ret = av_frame_ref(pict, &v->sprite_output_frame)) < 0)
            goto err;
        *got_frame = 1;
    } else {
        if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
            if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)
                goto err;
            ff_print_debug_info(s, s->current_picture_ptr, pict);
        } else if (s->last_picture_ptr != NULL) {
            if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)
                goto err;
            ff_print_debug_info(s, s->last_picture_ptr, pict);
        }
        if (s->last_picture_ptr || s->low_delay) {
            *got_frame = 1;
        }
    }

end:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return buf_size;

err:
    av_free(buf2);
    for (i = 0; i < n_slices; i++)
        av_free(slices[i].buf);
    av_free(slices);
    return -1;
}


static const AVProfile profiles[] = {
    { FF_PROFILE_VC1_SIMPLE,   "Simple"   },
    { FF_PROFILE_VC1_MAIN,     "Main"     },
    { FF_PROFILE_VC1_COMPLEX,  "Complex"  },
    { FF_PROFILE_VC1_ADVANCED, "Advanced" },
    { FF_PROFILE_UNKNOWN },
};

static const enum AVPixelFormat vc1_hwaccel_pixfmt_list_420[] = {
#if CONFIG_DXVA2
    AV_PIX_FMT_DXVA2_VLD,
#endif
#if CONFIG_VAAPI
    AV_PIX_FMT_VAAPI_VLD,
#endif
#if CONFIG_VDPAU
    AV_PIX_FMT_VDPAU,
#endif
    AV_PIX_FMT_YUV420P,
    AV_PIX_FMT_NONE
};

AVCodec ff_vc1_decoder = {
    .name           = "vc1",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_VC1,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .flush          = ff_mpeg_flush,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY,
    .long_name      = NULL_IF_CONFIG_SMALL("SMPTE VC-1"),
    .pix_fmts       = vc1_hwaccel_pixfmt_list_420,
    .profiles       = NULL_IF_CONFIG_SMALL(profiles)
};

#if CONFIG_WMV3_DECODER
AVCodec ff_wmv3_decoder = {
    .name           = "wmv3",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_WMV3,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .flush          = ff_mpeg_flush,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY,
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9"),
    .pix_fmts       = vc1_hwaccel_pixfmt_list_420,
    .profiles       = NULL_IF_CONFIG_SMALL(profiles)
};
#endif

#if CONFIG_WMV3_VDPAU_DECODER
AVCodec ff_wmv3_vdpau_decoder = {
    .name           = "wmv3_vdpau",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_WMV3,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 VDPAU"),
    .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_VDPAU_WMV3, AV_PIX_FMT_NONE },
    .profiles       = NULL_IF_CONFIG_SMALL(profiles)
};
#endif

#if CONFIG_VC1_VDPAU_DECODER
AVCodec ff_vc1_vdpau_decoder = {
    .name           = "vc1_vdpau",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_VC1,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
    .long_name      = NULL_IF_CONFIG_SMALL("SMPTE VC-1 VDPAU"),
    .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_VDPAU_VC1, AV_PIX_FMT_NONE },
    .profiles       = NULL_IF_CONFIG_SMALL(profiles)
};
#endif

#if CONFIG_WMV3IMAGE_DECODER
AVCodec ff_wmv3image_decoder = {
    .name           = "wmv3image",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_WMV3IMAGE,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .flush          = vc1_sprite_flush,
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 Image"),
    .pix_fmts       = ff_pixfmt_list_420
};
#endif

#if CONFIG_VC1IMAGE_DECODER
AVCodec ff_vc1image_decoder = {
    .name           = "vc1image",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_VC1IMAGE,
    .priv_data_size = sizeof(VC1Context),
    .init           = vc1_decode_init,
    .close          = ff_vc1_decode_end,
    .decode         = vc1_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .flush          = vc1_sprite_flush,
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 Image v2"),
    .pix_fmts       = ff_pixfmt_list_420
};
#endif