FFmpeg/libavcodec/ffv1.c

/*
 * FFV1 codec for libavcodec
 *
 * Copyright (c) 2003-2012 Michael Niedermayer <michaelni@gmx.at>
 *
 * 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
 * FF Video Codec 1 (a lossless codec)
 */

#include "libavutil/avassert.h"
#include "libavutil/crc.h"
#include "libavutil/opt.h"
#include "libavutil/imgutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timer.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "put_bits.h"
#include "dsputil.h"
#include "rangecoder.h"
#include "golomb.h"
#include "mathops.h"

#ifdef __INTEL_COMPILER
#undef av_flatten
#define av_flatten
#endif

#define MAX_PLANES 4
#define CONTEXT_SIZE 32

#define MAX_QUANT_TABLES 8
#define MAX_CONTEXT_INPUTS 5

extern const uint8_t ff_log2_run[41];

static const int8_t quant5_10bit[256] = {
     0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  1,  1,  1,  1,
     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
     1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,  1,
     1,  1,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -0, -0, -0, -0, -0, -0, -0, -0, -0, -0,
};

static const int8_t quant5[256] = {
     0,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -1,
};

static const int8_t quant9_10bit[256] = {
     0,  0,  0,  0,  0,  1,  1,  1,  1,  1,  1,  1,  1,  2,  2,  2,
     2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  2,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,  3,
     3,  3,  3,  3,  3,  3,  3,  3,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -3, -3, -3, -3, -3, -3, -3,
    -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3, -3,
    -3, -3, -3, -3, -3, -3, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
    -2, -2, -2, -2, -1, -1, -1, -1, -1, -1, -1, -1, -0, -0, -0, -0,
};

static const int8_t quant11[256] = {
     0,  1,  2,  2,  2,  3,  3,  3,  3,  3,  3,  3,  4,  4,  4,  4,
     4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,  4,
     4,  4,  4,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
     5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
     5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
     5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
     5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
     5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5,
    -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -5, -4, -4,
    -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4, -4,
    -4, -4, -4, -4, -4, -3, -3, -3, -3, -3, -3, -3, -2, -2, -2, -1,
};

static const uint8_t ver2_state[256] = {
      0,  10,  10,  10,  10,  16,  16,  16, 28,   16,  16,  29,  42,  49,  20,  49,
     59,  25,  26,  26,  27,  31,  33,  33, 33,   34,  34,  37,  67,  38,  39,  39,
     40,  40,  41,  79,  43,  44,  45,  45, 48,   48,  64,  50,  51,  52,  88,  52,
     53,  74,  55,  57,  58,  58,  74,  60, 101,  61,  62,  84,  66,  66,  68,  69,
     87,  82,  71,  97,  73,  73,  82,  75, 111,  77,  94,  78,  87,  81,  83,  97,
     85,  83,  94,  86,  99,  89,  90,  99, 111,  92,  93,  134, 95,  98,  105, 98,
    105, 110, 102, 108, 102, 118, 103, 106, 106, 113, 109, 112, 114, 112, 116, 125,
    115, 116, 117, 117, 126, 119, 125, 121, 121, 123, 145, 124, 126, 131, 127, 129,
    165, 130, 132, 138, 133, 135, 145, 136, 137, 139, 146, 141, 143, 142, 144, 148,
    147, 155, 151, 149, 151, 150, 152, 157, 153, 154, 156, 168, 158, 162, 161, 160,
    172, 163, 169, 164, 166, 184, 167, 170, 177, 174, 171, 173, 182, 176, 180, 178,
    175, 189, 179, 181, 186, 183, 192, 185, 200, 187, 191, 188, 190, 197, 193, 196,
    197, 194, 195, 196, 198, 202, 199, 201, 210, 203, 207, 204, 205, 206, 208, 214,
    209, 211, 221, 212, 213, 215, 224, 216, 217, 218, 219, 220, 222, 228, 223, 225,
    226, 224, 227, 229, 240, 230, 231, 232, 233, 234, 235, 236, 238, 239, 237, 242,
    241, 243, 242, 244, 245, 246, 247, 248, 249, 250, 251, 252, 252, 253, 254, 255,
};

typedef struct VlcState {
    int16_t drift;
    uint16_t error_sum;
    int8_t bias;
    uint8_t count;
} VlcState;

typedef struct PlaneContext {
    int16_t quant_table[MAX_CONTEXT_INPUTS][256];
    int quant_table_index;
    int context_count;
    uint8_t (*state)[CONTEXT_SIZE];
    VlcState *vlc_state;
    uint8_t interlace_bit_state[2];
} PlaneContext;

#define MAX_SLICES 256

typedef struct FFV1Context {
    AVClass *class;
    AVCodecContext *avctx;
    RangeCoder c;
    GetBitContext gb;
    PutBitContext pb;
    uint64_t rc_stat[256][2];
    uint64_t (*rc_stat2[MAX_QUANT_TABLES])[32][2];
    int version;
    int minor_version;
    int width, height;
    int chroma_h_shift, chroma_v_shift;
    int chroma_planes;
    int transparency;
    int flags;
    int picture_number;
    AVFrame picture;
    AVFrame last_picture;
    int plane_count;
    int ac;                              ///< 1=range coder <-> 0=golomb rice
    int ac_byte_count;                   ///< number of bytes used for AC coding
    PlaneContext plane[MAX_PLANES];
    int16_t quant_table[MAX_CONTEXT_INPUTS][256];
    int16_t quant_tables[MAX_QUANT_TABLES][MAX_CONTEXT_INPUTS][256];
    int context_count[MAX_QUANT_TABLES];
    uint8_t state_transition[256];
    uint8_t (*initial_states[MAX_QUANT_TABLES])[32];
    int run_index;
    int colorspace;
    int16_t *sample_buffer;
    int gob_count;
    int packed_at_lsb;
    int ec;
    int slice_damaged;
    int key_frame_ok;

    int quant_table_count;

    DSPContext dsp;

    struct FFV1Context *slice_context[MAX_SLICES];
    int slice_count;
    int num_v_slices;
    int num_h_slices;
    int slice_width;
    int slice_height;
    int slice_x;
    int slice_y;
    int bits_per_raw_sample;
} FFV1Context;

static av_always_inline int fold(int diff, int bits)
{
    if (bits == 8)
        diff = (int8_t)diff;
    else {
        diff +=  1 << (bits  - 1);
        diff &= (1 <<  bits) - 1;
        diff -=  1 << (bits  - 1);
    }

    return diff;
}

static inline int predict(int16_t *src, int16_t *last)
{
    const int LT = last[-1];
    const int T  = last[0];
    const int L  = src[-1];

    return mid_pred(L, L + T - LT, T);
}

static inline int get_context(PlaneContext *p, int16_t *src,
                              int16_t *last, int16_t *last2)
{
    const int LT = last[-1];
    const int T  = last[0];
    const int RT = last[1];
    const int L  = src[-1];

    if (p->quant_table[3][127]) {
        const int TT = last2[0];
        const int LL = src[-2];
        return p->quant_table[0][(L - LT) & 0xFF] +
               p->quant_table[1][(LT - T) & 0xFF] +
               p->quant_table[2][(T - RT) & 0xFF] +
               p->quant_table[3][(LL - L) & 0xFF] +
               p->quant_table[4][(TT - T) & 0xFF];
    } else
        return p->quant_table[0][(L - LT) & 0xFF] +
               p->quant_table[1][(LT - T) & 0xFF] +
               p->quant_table[2][(T - RT) & 0xFF];
}

static void find_best_state(uint8_t best_state[256][256],
                            const uint8_t one_state[256])
{
    int i, j, k, m;
    double l2tab[256];

    for (i = 1; i < 256; i++)
        l2tab[i] = log2(i / 256.0);

    for (i = 0; i < 256; i++) {
        double best_len[256];
        double p = i / 256.0;

        for (j = 0; j < 256; j++)
            best_len[j] = 1 << 30;

        for (j = FFMAX(i - 10, 1); j < FFMIN(i + 11, 256); j++) {
            double occ[256] = { 0 };
            double len      = 0;
            occ[j] = 1.0;
            for (k = 0; k < 256; k++) {
                double newocc[256] = { 0 };
                for (m = 1; m < 256; m++)
                    if (occ[m]) {
                        len -=occ[m]*(     p *l2tab[    m]
                                      + (1-p)*l2tab[256-m]);
                    }
                if (len < best_len[k]) {
                    best_len[k]      = len;
                    best_state[i][k] = j;
                }
                for (m = 0; m < 256; m++)
                    if (occ[m]) {
                        newocc[      one_state[      m]] += occ[m] * p;
                        newocc[256 - one_state[256 - m]] += occ[m] * (1 - p);
                    }
                memcpy(occ, newocc, sizeof(occ));
            }
        }
    }
}

static av_always_inline av_flatten void put_symbol_inline(RangeCoder *c,
                                                          uint8_t *state, int v,
                                                          int is_signed,
                                                          uint64_t rc_stat[256][2],
                                                          uint64_t rc_stat2[32][2])
{
    int i;

#define put_rac(C, S, B)                        \
    do {                                        \
        if (rc_stat) {                          \
            rc_stat[*(S)][B]++;                 \
            rc_stat2[(S) - state][B]++;         \
        }                                       \
        put_rac(C, S, B);                       \
    } while (0)

    if (v) {
        const int a = FFABS(v);
        const int e = av_log2(a);
        put_rac(c, state + 0, 0);
        if (e <= 9) {
            for (i = 0; i < e; i++)
                put_rac(c, state + 1 + i, 1);  // 1..10
            put_rac(c, state + 1 + i, 0);

            for (i = e - 1; i >= 0; i--)
                put_rac(c, state + 22 + i, (a >> i) & 1);  // 22..31

            if (is_signed)
                put_rac(c, state + 11 + e, v < 0);  // 11..21
        } else {
            for (i = 0; i < e; i++)
                put_rac(c, state + 1 + FFMIN(i, 9), 1);  // 1..10
            put_rac(c, state + 1 + 9, 0);

            for (i = e - 1; i >= 0; i--)
                put_rac(c, state + 22 + FFMIN(i, 9), (a >> i) & 1);  // 22..31

            if (is_signed)
                put_rac(c, state + 11 + 10, v < 0);  // 11..21
        }
    } else {
        put_rac(c, state + 0, 1);
    }
#undef put_rac
}

static av_noinline void put_symbol(RangeCoder *c, uint8_t *state,
                                   int v, int is_signed)
{
    put_symbol_inline(c, state, v, is_signed, NULL, NULL);
}

static inline av_flatten int get_symbol_inline(RangeCoder *c, uint8_t *state,
                                               int is_signed)
{
    if (get_rac(c, state + 0))
        return 0;
    else {
        int i, e, a;
        e = 0;
        while (get_rac(c, state + 1 + FFMIN(e, 9))) // 1..10
            e++;

        a = 1;
        for (i = e - 1; i >= 0; i--)
            a += a + get_rac(c, state + 22 + FFMIN(i, 9));  // 22..31

        e = -(is_signed && get_rac(c, state + 11 + FFMIN(e, 10))); // 11..21
        return (a ^ e) - e;
    }
}

static av_noinline int get_symbol(RangeCoder *c, uint8_t *state, int is_signed)
{
    return get_symbol_inline(c, state, is_signed);
}

static inline void update_vlc_state(VlcState *const state, const int v)
{
    int drift = state->drift;
    int count = state->count;
    state->error_sum += FFABS(v);
    drift            += v;

    if (count == 128) { // FIXME: variable
        count            >>= 1;
        drift            >>= 1;
        state->error_sum >>= 1;
    }
    count++;

    if (drift <= -count) {
        if (state->bias > -128)
            state->bias--;

        drift += count;
        if (drift <= -count)
            drift = -count + 1;
    } else if (drift > 0) {
        if (state->bias < 127)
            state->bias++;

        drift -= count;
        if (drift > 0)
            drift = 0;
    }

    state->drift = drift;
    state->count = count;
}

static inline void put_vlc_symbol(PutBitContext *pb, VlcState *const state,
                                  int v, int bits)
{
    int i, k, code;
    v = fold(v - state->bias, bits);

    i = state->count;
    k = 0;
    while (i < state->error_sum) { // FIXME: optimize
        k++;
        i += i;
    }

    av_assert2(k<=13);

#if 0 // JPEG LS
    if (k == 0 && 2 * state->drift <= -state->count)
        code = v ^ (-1);
    else
        code = v;
#else
    code = v ^ ((2 * state->drift + state->count) >> 31);
#endif

    av_dlog(NULL, "v:%d/%d bias:%d error:%d drift:%d count:%d k:%d\n", v, code,
            state->bias, state->error_sum, state->drift, state->count, k);
    set_sr_golomb(pb, code, k, 12, bits);

    update_vlc_state(state, v);
}

static inline int get_vlc_symbol(GetBitContext *gb, VlcState *const state,
                                 int bits)
{
    int k, i, v, ret;

    i = state->count;
    k = 0;
    while (i < state->error_sum) { // FIXME: optimize
        k++;
        i += i;
    }

    assert(k <= 8);

    v = get_sr_golomb(gb, k, 12, bits);
    av_dlog(NULL, "v:%d bias:%d error:%d drift:%d count:%d k:%d",
            v, state->bias, state->error_sum, state->drift, state->count, k);

#if 0 // JPEG LS
    if (k == 0 && 2 * state->drift <= -state->count)
        v ^= (-1);
#else
    v ^= ((2 * state->drift + state->count) >> 31);
#endif

    ret = fold(v + state->bias, bits);

    update_vlc_state(state, v);

    return ret;
}

#if CONFIG_FFV1_ENCODER
static av_always_inline int encode_line(FFV1Context *s, int w,
                                        int16_t *sample[3],
                                        int plane_index, int bits)
{
    PlaneContext *const p = &s->plane[plane_index];
    RangeCoder *const c   = &s->c;
    int x;
    int run_index = s->run_index;
    int run_count = 0;
    int run_mode  = 0;

    if (s->ac) {
        if (c->bytestream_end - c->bytestream < w * 20) {
            av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
            return -1;
        }
    } else {
        if (s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb) >> 3) < w * 4) {
            av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
            return -1;
        }
    }

    for (x = 0; x < w; x++) {
        int diff, context;

        context = get_context(p, sample[0] + x, sample[1] + x, sample[2] + x);
        diff    = sample[0][x] - predict(sample[0] + x, sample[1] + x);

        if (context < 0) {
            context = -context;
            diff    = -diff;
        }

        diff = fold(diff, bits);

        if (s->ac) {
            if (s->flags & CODEC_FLAG_PASS1) {
                put_symbol_inline(c, p->state[context], diff, 1, s->rc_stat,
                                  s->rc_stat2[p->quant_table_index][context]);
            } else {
                put_symbol_inline(c, p->state[context], diff, 1, NULL, NULL);
            }
        } else {
            if (context == 0)
                run_mode = 1;

            if (run_mode) {
                if (diff) {
                    while (run_count >= 1 << ff_log2_run[run_index]) {
                        run_count -= 1 << ff_log2_run[run_index];
                        run_index++;
                        put_bits(&s->pb, 1, 1);
                    }

                    put_bits(&s->pb, 1 + ff_log2_run[run_index], run_count);
                    if (run_index)
                        run_index--;
                    run_count = 0;
                    run_mode  = 0;
                    if (diff > 0)
                        diff--;
                } else {
                    run_count++;
                }
            }

            av_dlog(s->avctx, "count:%d index:%d, mode:%d, x:%d pos:%d\n",
                    run_count, run_index, run_mode, x,
                    (int)put_bits_count(&s->pb));

            if (run_mode == 0)
                put_vlc_symbol(&s->pb, &p->vlc_state[context], diff, bits);
        }
    }
    if (run_mode) {
        while (run_count >= 1 << ff_log2_run[run_index]) {
            run_count -= 1 << ff_log2_run[run_index];
            run_index++;
            put_bits(&s->pb, 1, 1);
        }

        if (run_count)
            put_bits(&s->pb, 1, 1);
    }
    s->run_index = run_index;

    return 0;
}

static void encode_plane(FFV1Context *s, uint8_t *src, int w, int h,
                         int stride, int plane_index)
{
    int x, y, i;
    const int ring_size = s->avctx->context_model ? 3 : 2;
    int16_t *sample[3];
    s->run_index = 0;

    memset(s->sample_buffer, 0, ring_size * (w + 6) * sizeof(*s->sample_buffer));

    for (y = 0; y < h; y++) {
        for (i = 0; i < ring_size; i++)
            sample[i] = s->sample_buffer + (w + 6) * ((h + i - y) % ring_size) + 3;

        sample[0][-1]= sample[1][0  ];
        sample[1][ w]= sample[1][w-1];
// { START_TIMER
        if (s->bits_per_raw_sample <= 8) {
            for (x = 0; x < w; x++)
                sample[0][x] = src[x + stride * y];
            encode_line(s, w, sample, plane_index, 8);
        } else {
            if (s->packed_at_lsb) {
                for (x = 0; x < w; x++) {
                    sample[0][x] = ((uint16_t*)(src + stride*y))[x];
                }
            } else {
                for (x = 0; x < w; x++) {
                    sample[0][x] = ((uint16_t*)(src + stride*y))[x] >> (16 - s->bits_per_raw_sample);
                }
            }
            encode_line(s, w, sample, plane_index, s->bits_per_raw_sample);
        }
// STOP_TIMER("encode line") }
    }
}

static void encode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h, int stride[3])
{
    int x, y, p, i;
    const int ring_size = s->avctx->context_model ? 3 : 2;
    int16_t *sample[4][3];
    int lbd    = s->avctx->bits_per_raw_sample <= 8;
    int bits   = s->avctx->bits_per_raw_sample > 0 ? s->avctx->bits_per_raw_sample : 8;
    int offset = 1 << bits;
    s->run_index = 0;

    memset(s->sample_buffer, 0, ring_size * 4 * (w + 6) * sizeof(*s->sample_buffer));

    for (y = 0; y < h; y++) {
        for (i = 0; i < ring_size; i++)
            for (p = 0; p < 4; p++)
                sample[p][i]= s->sample_buffer + p*ring_size*(w+6) + ((h+i-y)%ring_size)*(w+6) + 3;

        for (x = 0; x < w; x++) {
            int b, g, r, av_uninit(a);
            if (lbd) {
                unsigned v = *((uint32_t*)(src[0] + x*4 + stride[0]*y));
                b =  v        & 0xFF;
                g = (v >>  8) & 0xFF;
                r = (v >> 16) & 0xFF;
                a =  v >> 24;
            } else {
                b = *((uint16_t*)(src[0] + x*2 + stride[0]*y));
                g = *((uint16_t*)(src[1] + x*2 + stride[1]*y));
                r = *((uint16_t*)(src[2] + x*2 + stride[2]*y));
            }

            b -= g;
            r -= g;
            g += (b + r) >> 2;
            b += offset;
            r += offset;

            sample[0][0][x] = g;
            sample[1][0][x] = b;
            sample[2][0][x] = r;
            sample[3][0][x] = a;
        }
        for (p = 0; p < 3 + s->transparency; p++) {
            sample[p][0][-1] = sample[p][1][0  ];
            sample[p][1][ w] = sample[p][1][w-1];
            if (lbd)
                encode_line(s, w, sample[p], (p+1)/2, 9);
            else
                encode_line(s, w, sample[p], (p+1)/2, bits+1);
        }
    }
}

static void write_quant_table(RangeCoder *c, int16_t *quant_table)
{
    int last = 0;
    int i;
    uint8_t state[CONTEXT_SIZE];
    memset(state, 128, sizeof(state));

    for (i = 1; i < 128; i++)
        if (quant_table[i] != quant_table[i - 1]) {
            put_symbol(c, state, i - last - 1, 0);
            last = i;
        }
    put_symbol(c, state, i - last - 1, 0);
}

static void write_quant_tables(RangeCoder *c,
                               int16_t quant_table[MAX_CONTEXT_INPUTS][256])
{
    int i;
    for (i = 0; i < 5; i++)
        write_quant_table(c, quant_table[i]);
}

static void write_header(FFV1Context *f)
{
    uint8_t state[CONTEXT_SIZE];
    int i, j;
    RangeCoder *const c = &f->slice_context[0]->c;

    memset(state, 128, sizeof(state));

    if (f->version < 2) {
        put_symbol(c, state, f->version, 0);
        put_symbol(c, state, f->ac, 0);
        if (f->ac > 1) {
            for (i = 1; i < 256; i++)
                put_symbol(c, state,
                           f->state_transition[i] - c->one_state[i], 1);
        }
        put_symbol(c, state, f->colorspace, 0); //YUV cs type
        if (f->version > 0)
            put_symbol(c, state, f->bits_per_raw_sample, 0);
        put_rac(c, state, f->chroma_planes);
        put_symbol(c, state, f->chroma_h_shift, 0);
        put_symbol(c, state, f->chroma_v_shift, 0);
        put_rac(c, state, f->transparency);

        write_quant_tables(c, f->quant_table);
    } else if (f->version < 3) {
        put_symbol(c, state, f->slice_count, 0);
        for (i = 0; i < f->slice_count; i++) {
            FFV1Context *fs = f->slice_context[i];
            put_symbol(c, state,
                       (fs->slice_x      + 1) * f->num_h_slices / f->width, 0);
            put_symbol(c, state,
                       (fs->slice_y      + 1) * f->num_v_slices / f->height, 0);
            put_symbol(c, state,
                       (fs->slice_width  + 1) * f->num_h_slices / f->width - 1,
                       0);
            put_symbol(c, state,
                       (fs->slice_height + 1) * f->num_v_slices / f->height - 1,
                       0);
            for (j = 0; j < f->plane_count; j++) {
                put_symbol(c, state, f->plane[j].quant_table_index, 0);
                av_assert0(f->plane[j].quant_table_index == f->avctx->context_model);
            }
        }
    }
}

#endif /* CONFIG_FFV1_ENCODER */

static av_cold int common_init(AVCodecContext *avctx)
{
    FFV1Context *s = avctx->priv_data;

    if (!avctx->width || !avctx->height)
        return AVERROR_INVALIDDATA;

    s->avctx = avctx;
    s->flags = avctx->flags;

    avcodec_get_frame_defaults(&s->picture);

    ff_dsputil_init(&s->dsp, avctx);

    s->width  = avctx->width;
    s->height = avctx->height;

    // defaults
    s->num_h_slices = 1;
    s->num_v_slices = 1;

    return 0;
}

static int init_slice_state(FFV1Context *f, FFV1Context *fs)
{
    int j;

        fs->plane_count  = f->plane_count;
        fs->transparency = f->transparency;
        for (j = 0; j < f->plane_count; j++) {
            PlaneContext *const p = &fs->plane[j];

            if (fs->ac) {
                if (!p->state)
                    p->state = av_malloc(CONTEXT_SIZE * p->context_count *
                                         sizeof(uint8_t));
                if (!p->state)
                    return AVERROR(ENOMEM);
            } else {
                if (!p->vlc_state)
                    p->vlc_state = av_malloc(p->context_count * sizeof(VlcState));
                if (!p->vlc_state)
                    return AVERROR(ENOMEM);
            }
        }

        if (fs->ac > 1) {
            // FIXME: only redo if state_transition changed
            for (j = 1; j < 256; j++) {
                fs->c. one_state[      j] = f->state_transition[j];
                fs->c.zero_state[256 - j] = 256 - fs->c.one_state[j];
            }
        }

    return 0;
}

static int init_slices_state(FFV1Context *f) {
    int i;
    for (i = 0; i < f->slice_count; i++) {
        FFV1Context *fs = f->slice_context[i];
        if (init_slice_state(f, fs) < 0)
            return -1;
    }
    return 0;
}

static av_cold int init_slice_contexts(FFV1Context *f)
{
    int i;

    f->slice_count = f->num_h_slices * f->num_v_slices;

    for (i = 0; i < f->slice_count; i++) {
        FFV1Context *fs = av_mallocz(sizeof(*fs));
        int sx          = i % f->num_h_slices;
        int sy          = i / f->num_h_slices;
        int sxs         = f->avctx->width  *  sx      / f->num_h_slices;
        int sxe         = f->avctx->width  * (sx + 1) / f->num_h_slices;
        int sys         = f->avctx->height *  sy      / f->num_v_slices;
        int sye         = f->avctx->height * (sy + 1) / f->num_v_slices;
        f->slice_context[i] = fs;
        memcpy(fs, f, sizeof(*fs));
        memset(fs->rc_stat2, 0, sizeof(fs->rc_stat2));

        fs->slice_width  = sxe - sxs;
        fs->slice_height = sye - sys;
        fs->slice_x      = sxs;
        fs->slice_y      = sys;

        fs->sample_buffer = av_malloc(3*4 * (fs->width+6) * sizeof(*fs->sample_buffer));
        if (!fs->sample_buffer)
            return AVERROR(ENOMEM);
    }
    return 0;
}

static int allocate_initial_states(FFV1Context *f)
{
    int i;

    for (i = 0; i < f->quant_table_count; i++) {
        f->initial_states[i] = av_malloc(f->context_count[i] *
                                         sizeof(*f->initial_states[i]));
        if (!f->initial_states[i])
            return AVERROR(ENOMEM);
        memset(f->initial_states[i], 128,
               f->context_count[i] * sizeof(*f->initial_states[i]));
    }
    return 0;
}

#if CONFIG_FFV1_ENCODER
static int write_extra_header(FFV1Context *f)
{
    RangeCoder *const c = &f->c;
    uint8_t state[CONTEXT_SIZE];
    int i, j, k;
    uint8_t state2[32][CONTEXT_SIZE];
    unsigned v;

    memset(state2, 128, sizeof(state2));
    memset(state, 128, sizeof(state));

    f->avctx->extradata = av_malloc(f->avctx->extradata_size = 10000 +
                                    (11 * 11 * 5 * 5 * 5 + 11 * 11 * 11) * 32);
    ff_init_range_encoder(c, f->avctx->extradata, f->avctx->extradata_size);
    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);

    put_symbol(c, state, f->version, 0);
    if (f->version > 2) {
        if (f->version == 3)
            f->minor_version = 2;
        put_symbol(c, state, f->minor_version, 0);
    }
    put_symbol(c, state, f->ac, 0);
    if (f->ac > 1)
        for (i = 1; i < 256; i++)
            put_symbol(c, state, f->state_transition[i] - c->one_state[i], 1);
    put_symbol(c, state, f->colorspace, 0); // YUV cs type
    put_symbol(c, state, f->bits_per_raw_sample, 0);
    put_rac(c, state, f->chroma_planes);
    put_symbol(c, state, f->chroma_h_shift, 0);
    put_symbol(c, state, f->chroma_v_shift, 0);
    put_rac(c, state, f->transparency);
    put_symbol(c, state, f->num_h_slices - 1, 0);
    put_symbol(c, state, f->num_v_slices - 1, 0);

    put_symbol(c, state, f->quant_table_count, 0);
    for (i = 0; i < f->quant_table_count; i++)
        write_quant_tables(c, f->quant_tables[i]);

    for (i = 0; i < f->quant_table_count; i++) {
        for (j = 0; j < f->context_count[i] * CONTEXT_SIZE; j++)
            if (f->initial_states[i] && f->initial_states[i][0][j] != 128)
                break;
        if (j < f->context_count[i] * CONTEXT_SIZE) {
            put_rac(c, state, 1);
            for (j = 0; j < f->context_count[i]; j++)
                for (k = 0; k < CONTEXT_SIZE; k++) {
                    int pred = j ? f->initial_states[i][j - 1][k] : 128;
                    put_symbol(c, state2[k],
                               (int8_t)(f->initial_states[i][j][k] - pred), 1);
                }
        } else {
            put_rac(c, state, 0);
        }
    }

    if (f->version > 2) {
        put_symbol(c, state, f->ec, 0);
    }

    f->avctx->extradata_size = ff_rac_terminate(c);
    v = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, f->avctx->extradata, f->avctx->extradata_size);
    AV_WL32(f->avctx->extradata + f->avctx->extradata_size, v);
    f->avctx->extradata_size += 4;

    return 0;
}

static int sort_stt(FFV1Context *s, uint8_t stt[256])
{
    int i, i2, changed, print = 0;

    do {
        changed = 0;
        for (i = 12; i < 244; i++) {
            for (i2 = i + 1; i2 < 245 && i2 < i + 4; i2++) {

#define COST(old, new)                                      \
    s->rc_stat[old][0] * -log2((256 - (new)) / 256.0) +     \
    s->rc_stat[old][1] * -log2((new)         / 256.0)

#define COST2(old, new)                         \
    COST(old, new) + COST(256 - (old), 256 - (new))

                double size0 = COST2(i,  i) + COST2(i2, i2);
                double sizeX = COST2(i, i2) + COST2(i2, i);
                if (sizeX < size0 && i != 128 && i2 != 128) {
                    int j;
                    FFSWAP(int, stt[i], stt[i2]);
                    FFSWAP(int, s->rc_stat[i][0], s->rc_stat[i2][0]);
                    FFSWAP(int, s->rc_stat[i][1], s->rc_stat[i2][1]);
                    if (i != 256 - i2) {
                        FFSWAP(int, stt[256 - i], stt[256 - i2]);
                        FFSWAP(int, s->rc_stat[256 - i][0], s->rc_stat[256 - i2][0]);
                        FFSWAP(int, s->rc_stat[256 - i][1], s->rc_stat[256 - i2][1]);
                    }
                    for (j = 1; j < 256; j++) {
                        if (stt[j] == i)
                            stt[j] = i2;
                        else if (stt[j] == i2)
                            stt[j] = i;
                        if (i != 256 - i2) {
                            if (stt[256 - j] == 256 - i)
                                stt[256 - j] = 256 - i2;
                            else if (stt[256 - j] == 256 - i2)
                                stt[256 - j] = 256 - i;
                        }
                    }
                    print = changed = 1;
                }
            }
        }
    } while (changed);
    return print;
}

static av_cold int encode_init(AVCodecContext *avctx)
{
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
    FFV1Context *s = avctx->priv_data;
    int i, j, k, m;

    common_init(avctx);

    s->version = 0;

    if ((avctx->flags & (CODEC_FLAG_PASS1|CODEC_FLAG_PASS2)) || avctx->slices>1)
        s->version = FFMAX(s->version, 2);

    if (avctx->level == 3) {
        s->version = 3;
    }

    if (s->ec < 0) {
        s->ec = (s->version >= 3);
    }

    if (s->version >= 2 && avctx->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
        av_log(avctx, AV_LOG_ERROR, "Version 2 needed for requested features but version 2 is experimental and not enabled\n");
        return AVERROR_INVALIDDATA;
    }

    s->ac = avctx->coder_type > 0 ? 2 : 0;

    s->plane_count = 3;
    switch(avctx->pix_fmt) {
    case AV_PIX_FMT_YUV444P9:
    case AV_PIX_FMT_YUV422P9:
    case AV_PIX_FMT_YUV420P9:
        if (!avctx->bits_per_raw_sample)
            s->bits_per_raw_sample = 9;
    case AV_PIX_FMT_YUV444P10:
    case AV_PIX_FMT_YUV420P10:
    case AV_PIX_FMT_YUV422P10:
        s->packed_at_lsb = 1;
        if (!avctx->bits_per_raw_sample && !s->bits_per_raw_sample)
            s->bits_per_raw_sample = 10;
    case AV_PIX_FMT_GRAY16:
    case AV_PIX_FMT_YUV444P16:
    case AV_PIX_FMT_YUV422P16:
    case AV_PIX_FMT_YUV420P16:
        if (!avctx->bits_per_raw_sample && !s->bits_per_raw_sample) {
            s->bits_per_raw_sample = 16;
        } else if (!s->bits_per_raw_sample) {
            s->bits_per_raw_sample = avctx->bits_per_raw_sample;
        }
        if (s->bits_per_raw_sample <= 8) {
            av_log(avctx, AV_LOG_ERROR, "bits_per_raw_sample invalid\n");
            return AVERROR_INVALIDDATA;
        }
        if (!s->ac && avctx->coder_type == -1) {
            av_log(avctx, AV_LOG_INFO, "bits_per_raw_sample > 8, forcing coder 1\n");
            s->ac = 2;
        }
        if (!s->ac) {
            av_log(avctx, AV_LOG_ERROR, "bits_per_raw_sample of more than 8 needs -coder 1 currently\n");
            return AVERROR_INVALIDDATA;
        }
        s->version = FFMAX(s->version, 1);
    case AV_PIX_FMT_GRAY8:
    case AV_PIX_FMT_YUV444P:
    case AV_PIX_FMT_YUV440P:
    case AV_PIX_FMT_YUV422P:
    case AV_PIX_FMT_YUV420P:
    case AV_PIX_FMT_YUV411P:
    case AV_PIX_FMT_YUV410P:
        s->chroma_planes = desc->nb_components < 3 ? 0 : 1;
        s->colorspace = 0;
        break;
    case AV_PIX_FMT_YUVA444P:
    case AV_PIX_FMT_YUVA422P:
    case AV_PIX_FMT_YUVA420P:
        s->chroma_planes = 1;
        s->colorspace = 0;
        s->transparency = 1;
        break;
    case AV_PIX_FMT_RGB32:
        s->colorspace = 1;
        s->transparency = 1;
        break;
    case AV_PIX_FMT_0RGB32:
        s->colorspace = 1;
        break;
    case AV_PIX_FMT_GBRP9:
        if (!avctx->bits_per_raw_sample)
            s->bits_per_raw_sample = 9;
    case AV_PIX_FMT_GBRP10:
        if (!avctx->bits_per_raw_sample && !s->bits_per_raw_sample)
            s->bits_per_raw_sample = 10;
    case AV_PIX_FMT_GBRP12:
        if (!avctx->bits_per_raw_sample && !s->bits_per_raw_sample)
            s->bits_per_raw_sample = 12;
    case AV_PIX_FMT_GBRP14:
        if (!avctx->bits_per_raw_sample && !s->bits_per_raw_sample)
            s->bits_per_raw_sample = 14;
        else if (!s->bits_per_raw_sample)
            s->bits_per_raw_sample = avctx->bits_per_raw_sample;
        s->colorspace = 1;
        s->chroma_planes = 1;
        s->version = FFMAX(s->version, 1);
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "format not supported\n");
        return AVERROR_INVALIDDATA;
    }
    if (s->transparency) {
        av_log(avctx, AV_LOG_WARNING, "Storing alpha plane, this will require a recent FFV1 decoder to playback!\n");
    }
    if (avctx->context_model > 1U) {
        av_log(avctx, AV_LOG_ERROR, "Invalid context model %d, valid values are 0 and 1\n", avctx->context_model);
        return AVERROR(EINVAL);
    }

    if (s->ac > 1)
        for (i = 1; i < 256; i++)
            s->state_transition[i] = ver2_state[i];

    for (i = 0; i < 256; i++) {
        s->quant_table_count = 2;
        if (s->bits_per_raw_sample <= 8) {
            s->quant_tables[0][0][i]=           quant11[i];
            s->quant_tables[0][1][i]=        11*quant11[i];
            s->quant_tables[0][2][i]=     11*11*quant11[i];
            s->quant_tables[1][0][i]=           quant11[i];
            s->quant_tables[1][1][i]=        11*quant11[i];
            s->quant_tables[1][2][i]=     11*11*quant5 [i];
            s->quant_tables[1][3][i]=   5*11*11*quant5 [i];
            s->quant_tables[1][4][i]= 5*5*11*11*quant5 [i];
        } else {
            s->quant_tables[0][0][i]=           quant9_10bit[i];
            s->quant_tables[0][1][i]=        11*quant9_10bit[i];
            s->quant_tables[0][2][i]=     11*11*quant9_10bit[i];
            s->quant_tables[1][0][i]=           quant9_10bit[i];
            s->quant_tables[1][1][i]=        11*quant9_10bit[i];
            s->quant_tables[1][2][i]=     11*11*quant5_10bit[i];
            s->quant_tables[1][3][i]=   5*11*11*quant5_10bit[i];
            s->quant_tables[1][4][i]= 5*5*11*11*quant5_10bit[i];
        }
    }
    s->context_count[0] = (11 * 11 * 11        + 1) / 2;
    s->context_count[1] = (11 * 11 * 5 * 5 * 5 + 1) / 2;
    memcpy(s->quant_table, s->quant_tables[avctx->context_model],
           sizeof(s->quant_table));

    for (i = 0; i < s->plane_count; i++) {
        PlaneContext *const p = &s->plane[i];

        memcpy(p->quant_table, s->quant_table, sizeof(p->quant_table));
        p->quant_table_index = avctx->context_model;
        p->context_count     = s->context_count[p->quant_table_index];
    }

    if (allocate_initial_states(s) < 0)
        return AVERROR(ENOMEM);

    avctx->coded_frame = &s->picture;
    if (!s->transparency)
        s->plane_count = 2;
    avcodec_get_chroma_sub_sample(avctx->pix_fmt, &s->chroma_h_shift, &s->chroma_v_shift);
    s->picture_number = 0;

    if (avctx->flags & (CODEC_FLAG_PASS1 | CODEC_FLAG_PASS2)) {
        for (i = 0; i < s->quant_table_count; i++) {
            s->rc_stat2[i] = av_mallocz(s->context_count[i] *
                                        sizeof(*s->rc_stat2[i]));
            if (!s->rc_stat2[i])
                return AVERROR(ENOMEM);
        }
    }
    if (avctx->stats_in) {
        char *p = avctx->stats_in;
        uint8_t best_state[256][256];
        int gob_count = 0;
        char *next;

        av_assert0(s->version >= 2);

        for (;;) {
            for (j = 0; j < 256; j++)
                for (i = 0; i < 2; i++) {
                    s->rc_stat[j][i] = strtol(p, &next, 0);
                    if (next == p) {
                        av_log(avctx, AV_LOG_ERROR,
                               "2Pass file invalid at %d %d [%s]\n", j, i, p);
                        return -1;
                    }
                    p = next;
                }
            for (i = 0; i < s->quant_table_count; i++)
                for (j = 0; j < s->context_count[i]; j++) {
                    for (k = 0; k < 32; k++)
                        for (m = 0; m < 2; m++) {
                            s->rc_stat2[i][j][k][m] = strtol(p, &next, 0);
                            if (next == p) {
                                av_log(avctx, AV_LOG_ERROR,
                                       "2Pass file invalid at %d %d %d %d [%s]\n",
                                       i, j, k, m, p);
                                return AVERROR_INVALIDDATA;
                            }
                            p = next;
                        }
                }
            gob_count = strtol(p, &next, 0);
            if (next == p || gob_count <= 0) {
                av_log(avctx, AV_LOG_ERROR, "2Pass file invalid\n");
                return AVERROR_INVALIDDATA;
            }
            p = next;
            while (*p == '\n' || *p == ' ')
                p++;
            if (p[0] == 0)
                break;
        }
        sort_stt(s, s->state_transition);

        find_best_state(best_state, s->state_transition);

        for (i = 0; i < s->quant_table_count; i++) {
            for (j = 0; j < s->context_count[i]; j++)
                for (k = 0; k < 32; k++) {
                    double p = 128;
                    if (s->rc_stat2[i][j][k][0] + s->rc_stat2[i][j][k][1]) {
                        p = 256.0 * s->rc_stat2[i][j][k][1] /
                            (s->rc_stat2[i][j][k][0] + s->rc_stat2[i][j][k][1]);
                    }
                    s->initial_states[i][j][k] =
                        best_state[av_clip(round(p), 1, 255)][av_clip((s->rc_stat2[i][j][k][0] +
                                                                       s->rc_stat2[i][j][k][1]) /
                                                                      gob_count, 0, 255)];
                }
        }
    }

    if (s->version > 1) {
        for (s->num_v_slices = 2; s->num_v_slices < 9; s->num_v_slices++) {
            for (s->num_h_slices = s->num_v_slices; s->num_h_slices < 2*s->num_v_slices; s->num_h_slices++) {
                if (avctx->slices == s->num_h_slices * s->num_v_slices && avctx->slices <= 64 || !avctx->slices)
                    goto slices_ok;
            }
        }
        av_log(avctx, AV_LOG_ERROR, "Unsupported number %d of slices requested, please specify a supported number with -slices (ex:4,6,9,12,16, ...)\n", avctx->slices);
        return -1;
        slices_ok:
        write_extra_header(s);
    }

    if (init_slice_contexts(s) < 0)
        return -1;
    if (init_slices_state(s) < 0)
        return -1;

#define STATS_OUT_SIZE 1024 * 1024 * 6
    if (avctx->flags & CODEC_FLAG_PASS1) {
        avctx->stats_out = av_mallocz(STATS_OUT_SIZE);
        for (i = 0; i < s->quant_table_count; i++)
            for (j = 0; j < s->slice_count; j++) {
                FFV1Context *sf = s->slice_context[j];
                av_assert0(!sf->rc_stat2[i]);
                sf->rc_stat2[i] = av_mallocz(s->context_count[i] *
                                             sizeof(*sf->rc_stat2[i]));
                if (!sf->rc_stat2[i])
                    return AVERROR(ENOMEM);
            }
    }

    return 0;
}

#endif /* CONFIG_FFV1_ENCODER */


static void clear_slice_state(FFV1Context *f, FFV1Context *fs)
{
    int i, j;

        for (i = 0; i < f->plane_count; i++) {
            PlaneContext *p = &fs->plane[i];

            p->interlace_bit_state[0] = 128;
            p->interlace_bit_state[1] = 128;

            if (fs->ac) {
                if (f->initial_states[p->quant_table_index]) {
                    memcpy(p->state, f->initial_states[p->quant_table_index],
                           CONTEXT_SIZE * p->context_count);
                } else
                    memset(p->state, 128, CONTEXT_SIZE * p->context_count);
            } else {
                for (j = 0; j < p->context_count; j++) {
                    p->vlc_state[j].drift     = 0;
                    p->vlc_state[j].error_sum = 4; // FFMAX((RANGE + 32)/64, 2);
                    p->vlc_state[j].bias      = 0;
                    p->vlc_state[j].count     = 1;
                }
            }
        }
}

#if CONFIG_FFV1_ENCODER

static void encode_slice_header(FFV1Context *f, FFV1Context *fs)
{
    RangeCoder *c = &fs->c;
    uint8_t state[CONTEXT_SIZE];
    int j;
    memset(state, 128, sizeof(state));

    put_symbol(c, state, (fs->slice_x     +1)*f->num_h_slices / f->width   , 0);
    put_symbol(c, state, (fs->slice_y     +1)*f->num_v_slices / f->height  , 0);
    put_symbol(c, state, (fs->slice_width +1)*f->num_h_slices / f->width -1, 0);
    put_symbol(c, state, (fs->slice_height+1)*f->num_v_slices / f->height-1, 0);
    for (j=0; j<f->plane_count; j++) {
        put_symbol(c, state, f->plane[j].quant_table_index, 0);
        av_assert0(f->plane[j].quant_table_index == f->avctx->context_model);
    }
    if (!f->picture.interlaced_frame) put_symbol(c, state, 3, 0);
    else                             put_symbol(c, state, 1 + !f->picture.top_field_first, 0);
    put_symbol(c, state, f->picture.sample_aspect_ratio.num, 0);
    put_symbol(c, state, f->picture.sample_aspect_ratio.den, 0);
}

static int encode_slice(AVCodecContext *c, void *arg)
{
    FFV1Context *fs  = *(void **)arg;
    FFV1Context *f   = fs->avctx->priv_data;
    int width        = fs->slice_width;
    int height       = fs->slice_height;
    int x            = fs->slice_x;
    int y            = fs->slice_y;
    AVFrame *const p = &f->picture;
    const int ps     = (av_pix_fmt_desc_get(c->pix_fmt)->flags & PIX_FMT_PLANAR)
                            ?
                       (f->bits_per_raw_sample>8)+1
                            :
                       4;

    if (p->key_frame)
        clear_slice_state(f, fs);
    if (f->version > 2) {
        encode_slice_header(f, fs);
    }
    if (!fs->ac) {
        if (f->version > 2)
            put_rac(&fs->c, (uint8_t[]) {129}, 0);
        fs->ac_byte_count = f->version > 2 || (!x&&!y) ? ff_rac_terminate(&fs->c) : 0;
        init_put_bits(&fs->pb, fs->c.bytestream_start + fs->ac_byte_count, fs->c.bytestream_end - fs->c.bytestream_start - fs->ac_byte_count);
    }

    if (f->colorspace == 0) {
        const int chroma_width  = -((-width) >> f->chroma_h_shift);
        const int chroma_height = -((-height) >> f->chroma_v_shift);
        const int cx            = x >> f->chroma_h_shift;
        const int cy            = y >> f->chroma_v_shift;

        encode_plane(fs, p->data[0] + ps*x + y*p->linesize[0], width, height, p->linesize[0], 0);

        if (f->chroma_planes) {
            encode_plane(fs, p->data[1] + ps*cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[1], 1);
            encode_plane(fs, p->data[2] + ps*cx+cy*p->linesize[2], chroma_width, chroma_height, p->linesize[2], 1);
        }
        if (fs->transparency)
            encode_plane(fs, p->data[3] + ps*x + y*p->linesize[3], width, height, p->linesize[3], 2);
    } else {
        uint8_t *planes[3] = {p->data[0] + ps*x + y*p->linesize[0],
                              p->data[1] + ps*x + y*p->linesize[1],
                              p->data[2] + ps*x + y*p->linesize[2]};
        encode_rgb_frame(fs, planes, width, height, p->linesize);
    }
    emms_c();

    return 0;
}

static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                        const AVFrame *pict, int *got_packet)
{
    FFV1Context *f      = avctx->priv_data;
    RangeCoder *const c = &f->slice_context[0]->c;
    AVFrame *const p    = &f->picture;
    int used_count      = 0;
    uint8_t keystate    = 128;
    uint8_t *buf_p;
    int i, ret;

    if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*((8*2+1+1)*4)/8
                                            + FF_MIN_BUFFER_SIZE)) < 0)
        return ret;

    ff_init_range_encoder(c, pkt->data, pkt->size);
    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);

    *p           = *pict;
    p->pict_type = AV_PICTURE_TYPE_I;

    if (avctx->gop_size == 0 || f->picture_number % avctx->gop_size == 0) {
        put_rac(c, &keystate, 1);
        p->key_frame = 1;
        f->gob_count++;
        write_header(f);
    } else {
        put_rac(c, &keystate, 0);
        p->key_frame = 0;
    }

    if (f->ac > 1) {
        int i;
        for (i = 1; i < 256; i++) {
            c->one_state[i]        = f->state_transition[i];
            c->zero_state[256 - i] = 256 - c->one_state[i];
        }
    }

    for (i = 1; i < f->slice_count; i++) {
        FFV1Context *fs = f->slice_context[i];
        uint8_t *start  = pkt->data + (pkt->size - used_count) * (int64_t)i / f->slice_count;
        int len         = pkt->size / f->slice_count;
        ff_init_range_encoder(&fs->c, start, len);
    }
    avctx->execute(avctx, encode_slice, &f->slice_context[0], NULL,
                   f->slice_count, sizeof(void *));

    buf_p = pkt->data;
    for (i = 0; i < f->slice_count; i++) {
        FFV1Context *fs = f->slice_context[i];
        int bytes;

        if (fs->ac) {
            uint8_t state=129;
            put_rac(&fs->c, &state, 0);
            bytes = ff_rac_terminate(&fs->c);
        } else {
            flush_put_bits(&fs->pb); // FIXME: nicer padding
            bytes = fs->ac_byte_count + (put_bits_count(&fs->pb) + 7)/8;
        }
        if (i > 0 || f->version > 2) {
            av_assert0(bytes < pkt->size / f->slice_count);
            memmove(buf_p, fs->c.bytestream_start, bytes);
            av_assert0(bytes < (1 << 24));
            AV_WB24(buf_p + bytes, bytes);
            bytes += 3;
        }
        if (f->ec) {
            unsigned v;
            buf_p[bytes++] = 0;
            v = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, buf_p, bytes);
            AV_WL32(buf_p + bytes, v); bytes += 4;
        }
        buf_p += bytes;
    }

    if ((avctx->flags & CODEC_FLAG_PASS1) && (f->picture_number & 31) == 0) {
        int j, k, m;
        char *p   = avctx->stats_out;
        char *end = p + STATS_OUT_SIZE;

        memset(f->rc_stat, 0, sizeof(f->rc_stat));
        for (i = 0; i < f->quant_table_count; i++)
            memset(f->rc_stat2[i], 0, f->context_count[i] * sizeof(*f->rc_stat2[i]));

        for (j = 0; j < f->slice_count; j++) {
            FFV1Context *fs = f->slice_context[j];
            for (i = 0; i < 256; i++) {
                f->rc_stat[i][0] += fs->rc_stat[i][0];
                f->rc_stat[i][1] += fs->rc_stat[i][1];
            }
            for (i = 0; i < f->quant_table_count; i++) {
                for (k = 0; k < f->context_count[i]; k++)
                    for (m = 0; m < 32; m++) {
                        f->rc_stat2[i][k][m][0] += fs->rc_stat2[i][k][m][0];
                        f->rc_stat2[i][k][m][1] += fs->rc_stat2[i][k][m][1];
                    }
            }
        }

        for (j = 0; j < 256; j++) {
            snprintf(p, end - p, "%" PRIu64 " %" PRIu64 " ",
                     f->rc_stat[j][0], f->rc_stat[j][1]);
            p += strlen(p);
        }
        snprintf(p, end - p, "\n");

        for (i = 0; i < f->quant_table_count; i++) {
            for (j = 0; j < f->context_count[i]; j++)
                for (m = 0; m < 32; m++) {
                    snprintf(p, end - p, "%" PRIu64 " %" PRIu64 " ",
                             f->rc_stat2[i][j][m][0], f->rc_stat2[i][j][m][1]);
                    p += strlen(p);
                }
        }
        snprintf(p, end - p, "%d\n", f->gob_count);
    } else if (avctx->flags & CODEC_FLAG_PASS1)
        avctx->stats_out[0] = '\0';

    f->picture_number++;
    pkt->size   = buf_p - pkt->data;
    pkt->flags |= AV_PKT_FLAG_KEY * p->key_frame;
    *got_packet = 1;

    return 0;
}

#endif /* CONFIG_FFV1_ENCODER */

static av_cold int common_end(AVCodecContext *avctx)
{
    FFV1Context *s = avctx->priv_data;
    int i, j;

    if (avctx->codec->decode && s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);
    if (avctx->codec->decode && s->last_picture.data[0])
        avctx->release_buffer(avctx, &s->last_picture);

    for (j = 0; j < s->slice_count; j++) {
        FFV1Context *fs = s->slice_context[j];
        for (i = 0; i < s->plane_count; i++) {
            PlaneContext *p = &fs->plane[i];

            av_freep(&p->state);
            av_freep(&p->vlc_state);
        }
        av_freep(&fs->sample_buffer);
    }

    av_freep(&avctx->stats_out);
    for (j = 0; j < s->quant_table_count; j++) {
        av_freep(&s->initial_states[j]);
        for (i = 0; i < s->slice_count; i++) {
            FFV1Context *sf = s->slice_context[i];
            av_freep(&sf->rc_stat2[j]);
        }
        av_freep(&s->rc_stat2[j]);
    }

    for (i = 0; i < s->slice_count; i++)
        av_freep(&s->slice_context[i]);

    return 0;
}

static av_always_inline void decode_line(FFV1Context *s, int w,
                                         int16_t *sample[2],
                                         int plane_index, int bits)
{
    PlaneContext *const p = &s->plane[plane_index];
    RangeCoder *const c   = &s->c;
    int x;
    int run_count = 0;
    int run_mode  = 0;
    int run_index = s->run_index;

    for (x = 0; x < w; x++) {
        int diff, context, sign;

        context = get_context(p, sample[1] + x, sample[0] + x, sample[1] + x);
        if (context < 0) {
            context = -context;
            sign    = 1;
        } else
            sign = 0;

        av_assert2(context < p->context_count);

        if (s->ac) {
            diff = get_symbol_inline(c, p->state[context], 1);
        } else {
            if (context == 0 && run_mode == 0)
                run_mode = 1;

            if (run_mode) {
                if (run_count == 0 && run_mode == 1) {
                    if (get_bits1(&s->gb)) {
                        run_count = 1 << ff_log2_run[run_index];
                        if (x + run_count <= w)
                            run_index++;
                    } else {
                        if (ff_log2_run[run_index])
                            run_count = get_bits(&s->gb, ff_log2_run[run_index]);
                        else
                            run_count = 0;
                        if (run_index)
                            run_index--;
                        run_mode = 2;
                    }
                }
                run_count--;
                if (run_count < 0) {
                    run_mode  = 0;
                    run_count = 0;
                    diff      = get_vlc_symbol(&s->gb, &p->vlc_state[context],
                                               bits);
                    if (diff >= 0)
                        diff++;
                } else
                    diff = 0;
            } else
                diff = get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);

            av_dlog(s->avctx, "count:%d index:%d, mode:%d, x:%d pos:%d\n",
                    run_count, run_index, run_mode, x, get_bits_count(&s->gb));
        }

        if (sign)
            diff = -diff;

        sample[1][x] = (predict(sample[1] + x, sample[0] + x) + diff) &
                       ((1 << bits) - 1);
    }
    s->run_index = run_index;
}

static void decode_plane(FFV1Context *s, uint8_t *src,
                         int w, int h, int stride, int plane_index)
{
    int x, y;
    int16_t *sample[2];
    sample[0] = s->sample_buffer + 3;
    sample[1] = s->sample_buffer + w + 6 + 3;

    s->run_index = 0;

    memset(s->sample_buffer, 0, 2 * (w + 6) * sizeof(*s->sample_buffer));

    for (y = 0; y < h; y++) {
        int16_t *temp = sample[0]; // FIXME: try a normal buffer

        sample[0] = sample[1];
        sample[1] = temp;

        sample[1][-1] = sample[0][0];
        sample[0][w]  = sample[0][w - 1];

// { START_TIMER
        if (s->avctx->bits_per_raw_sample <= 8) {
            decode_line(s, w, sample, plane_index, 8);
            for (x = 0; x < w; x++)
                src[x + stride * y] = sample[1][x];
        } else {
            decode_line(s, w, sample, plane_index, s->avctx->bits_per_raw_sample);
            if (s->packed_at_lsb) {
                for (x = 0; x < w; x++) {
                    ((uint16_t*)(src + stride*y))[x] = sample[1][x];
                }
            } else {
                for (x = 0; x < w; x++) {
                    ((uint16_t*)(src + stride*y))[x] = sample[1][x] << (16 - s->avctx->bits_per_raw_sample);
                }
            }
        }
// STOP_TIMER("decode-line") }
    }
}

static void decode_rgb_frame(FFV1Context *s, uint8_t *src[3], int w, int h, int stride[3])
{
    int x, y, p;
    int16_t *sample[4][2];
    int lbd  = s->avctx->bits_per_raw_sample <= 8;
    int bits = s->avctx->bits_per_raw_sample > 0 ? s->avctx->bits_per_raw_sample : 8;
    int offset = 1 << bits;
    for (x = 0; x < 4; x++) {
        sample[x][0] = s->sample_buffer +  x * 2      * (w + 6) + 3;
        sample[x][1] = s->sample_buffer + (x * 2 + 1) * (w + 6) + 3;
    }

    s->run_index = 0;

    memset(s->sample_buffer, 0, 8*(w+6)*sizeof(*s->sample_buffer));

    for (y = 0; y < h; y++) {
        for (p = 0; p < 3 + s->transparency; p++) {
            int16_t *temp = sample[p][0]; // FIXME: try a normal buffer

            sample[p][0] = sample[p][1];
            sample[p][1] = temp;

            sample[p][1][-1]= sample[p][0][0  ];
            sample[p][0][ w]= sample[p][0][w-1];
            if (lbd)
                decode_line(s, w, sample[p], (p+1)/2, 9);
            else
                decode_line(s, w, sample[p], (p+1)/2, bits+1);
        }
        for (x = 0; x < w; x++) {
            int g = sample[0][1][x];
            int b = sample[1][1][x];
            int r = sample[2][1][x];
            int a = sample[3][1][x];

            b -= offset;
            r -= offset;
            g -= (b + r) >> 2;
            b += g;
            r += g;

            if (lbd)
                *((uint32_t*)(src[0] + x*4 + stride[0]*y)) = b + (g<<8) + (r<<16) + (a<<24);
            else {
                *((uint16_t*)(src[0] + x*2 + stride[0]*y)) = b;
                *((uint16_t*)(src[1] + x*2 + stride[1]*y)) = g;
                *((uint16_t*)(src[2] + x*2 + stride[2]*y)) = r;
            }
        }
    }
}

static int decode_slice_header(FFV1Context *f, FFV1Context *fs)
{
    RangeCoder *c = &fs->c;
    uint8_t state[CONTEXT_SIZE];
    unsigned ps, i, context_count;
    memset(state, 128, sizeof(state));

    av_assert0(f->version > 2);

    fs->slice_x      =  get_symbol(c, state, 0)      * f->width ;
    fs->slice_y      =  get_symbol(c, state, 0)      * f->height;
    fs->slice_width  = (get_symbol(c, state, 0) + 1) * f->width  + fs->slice_x;
    fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;

    fs->slice_x /= f->num_h_slices;
    fs->slice_y /= f->num_v_slices;
    fs->slice_width  = fs->slice_width /f->num_h_slices - fs->slice_x;
    fs->slice_height = fs->slice_height/f->num_v_slices - fs->slice_y;
    if ((unsigned)fs->slice_width > f->width || (unsigned)fs->slice_height > f->height)
        return -1;
    if (    (unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width
         || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
        return -1;

    for (i = 0; i < f->plane_count; i++) {
        PlaneContext * const p = &fs->plane[i];
        int idx = get_symbol(c, state, 0);
        if (idx > (unsigned)f->quant_table_count) {
            av_log(f->avctx, AV_LOG_ERROR, "quant_table_index out of range\n");
            return -1;
        }
        p->quant_table_index = idx;
        memcpy(p->quant_table, f->quant_tables[idx], sizeof(p->quant_table));
        context_count = f->context_count[idx];

        if (p->context_count < context_count) {
            av_freep(&p->state);
            av_freep(&p->vlc_state);
        }
        p->context_count = context_count;
    }

    ps = get_symbol(c, state, 0);
    if (ps == 1) {
        f->picture.interlaced_frame = 1;
        f->picture.top_field_first  = 1;
    } else if (ps == 2) {
        f->picture.interlaced_frame = 1;
        f->picture.top_field_first  = 0;
    } else if (ps == 3) {
        f->picture.interlaced_frame = 0;
    }
    f->picture.sample_aspect_ratio.num = get_symbol(c, state, 0);
    f->picture.sample_aspect_ratio.den = get_symbol(c, state, 0);

    return 0;
}

static int decode_slice(AVCodecContext *c, void *arg)
{
    FFV1Context *fs  = *(void **)arg;
    FFV1Context *f   = fs->avctx->priv_data;
    int width, height, x, y;
    const int ps = (av_pix_fmt_desc_get(c->pix_fmt)->flags & PIX_FMT_PLANAR)
                        ?
                   (c->bits_per_raw_sample>8)+1
                        :
                    4;
    AVFrame * const p = &f->picture;

    if (f->version > 2) {
        if (init_slice_state(f, fs) < 0)
            return AVERROR(ENOMEM);
        if (decode_slice_header(f, fs) < 0) {
            fs->slice_damaged = 1;
            return AVERROR_INVALIDDATA;
        }
    }
    if (init_slice_state(f, fs) < 0)
        return AVERROR(ENOMEM);
    if (f->picture.key_frame)
        clear_slice_state(f, fs);
    width = fs->slice_width;
    height= fs->slice_height;
    x= fs->slice_x;
    y= fs->slice_y;

    if (!fs->ac) {
        if (f->version == 3 && f->minor_version > 1 || f->version > 3)
            get_rac(&fs->c, (uint8_t[]) {129});
        fs->ac_byte_count = f->version > 2 || (!x&&!y) ? fs->c.bytestream - fs->c.bytestream_start - 1 : 0;
        init_get_bits(&fs->gb,
                      fs->c.bytestream_start + fs->ac_byte_count,
                      (fs->c.bytestream_end - fs->c.bytestream_start - fs->ac_byte_count) * 8);
    }

    av_assert1(width && height);
    if (f->colorspace == 0) {
        const int chroma_width  = -((-width)  >> f->chroma_h_shift);
        const int chroma_height = -((-height) >> f->chroma_v_shift);
        const int cx            = x >> f->chroma_h_shift;
        const int cy            = y >> f->chroma_v_shift;
        decode_plane(fs, p->data[0] + ps*x + y*p->linesize[0], width, height, p->linesize[0], 0);

        if (f->chroma_planes) {
            decode_plane(fs, p->data[1] + ps*cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[1], 1);
            decode_plane(fs, p->data[2] + ps*cx+cy*p->linesize[2], chroma_width, chroma_height, p->linesize[2], 1);
        }
        if (fs->transparency)
            decode_plane(fs, p->data[3] + ps*x + y*p->linesize[3], width, height, p->linesize[3], 2);
    } else {
        uint8_t *planes[3] = {p->data[0] + ps*x + y*p->linesize[0],
                              p->data[1] + ps*x + y*p->linesize[1],
                              p->data[2] + ps*x + y*p->linesize[2]};
        decode_rgb_frame(fs, planes, width, height, p->linesize);
    }
    if (fs->ac && f->version > 2) {
        int v;
        get_rac(&fs->c, (uint8_t[]) {129});
        v = fs->c.bytestream_end - fs->c.bytestream - 2 - 5*f->ec;
        if (v) {
            av_log(f->avctx, AV_LOG_ERROR, "bytestream end mismatching by %d\n", v);
            fs->slice_damaged = 1;
        }
    }

    emms_c();

    return 0;
}

static int read_quant_table(RangeCoder *c, int16_t *quant_table, int scale)
{
    int v;
    int i = 0;
    uint8_t state[CONTEXT_SIZE];

    memset(state, 128, sizeof(state));

    for (v = 0; i < 128; v++) {
        unsigned len = get_symbol(c, state, 0) + 1;

        if (len > 128 - i)
            return -1;

        while (len--) {
            quant_table[i] = scale * v;
            i++;
        }
    }

    for (i = 1; i < 128; i++)
        quant_table[256 - i] = -quant_table[i];
    quant_table[128] = -quant_table[127];

    return 2 * v - 1;
}

static int read_quant_tables(RangeCoder *c,
                             int16_t quant_table[MAX_CONTEXT_INPUTS][256])
{
    int i;
    int context_count = 1;

    for (i = 0; i < 5; i++) {
        context_count *= read_quant_table(c, quant_table[i], context_count);
        if (context_count > 32768U) {
            return -1;
        }
    }
    return (context_count + 1) / 2;
}

static int read_extra_header(FFV1Context *f)
{
    RangeCoder *const c = &f->c;
    uint8_t state[CONTEXT_SIZE];
    int i, j, k;
    uint8_t state2[32][CONTEXT_SIZE];

    memset(state2, 128, sizeof(state2));
    memset(state, 128, sizeof(state));

    ff_init_range_decoder(c, f->avctx->extradata, f->avctx->extradata_size);
    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);

    f->version = get_symbol(c, state, 0);
    if (f->version > 2) {
        c->bytestream_end -= 4;
        f->minor_version = get_symbol(c, state, 0);
    }
    f->ac = f->avctx->coder_type = get_symbol(c, state, 0);
    if (f->ac > 1)
        for (i = 1; i < 256; i++)
            f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];

    f->colorspace                 = get_symbol(c, state, 0); // YUV cs type
    f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
    f->chroma_planes  = get_rac(c, state);
    f->chroma_h_shift = get_symbol(c, state, 0);
    f->chroma_v_shift = get_symbol(c, state, 0);
    f->transparency = get_rac(c, state);
    f->plane_count  = 2 + f->transparency;
    f->num_h_slices = 1 + get_symbol(c, state, 0);
    f->num_v_slices = 1 + get_symbol(c, state, 0);

    if (f->num_h_slices > (unsigned)f->width ||
        f->num_v_slices > (unsigned)f->height) {
        av_log(f->avctx, AV_LOG_ERROR, "too many slices\n");
        return -1;
    }

    f->quant_table_count = get_symbol(c, state, 0);

    if (f->quant_table_count > (unsigned)MAX_QUANT_TABLES)
        return -1;

    for (i = 0; i < f->quant_table_count; i++) {
        f->context_count[i] = read_quant_tables(c, f->quant_tables[i]);
        if (f->context_count[i] < 0) {
            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
            return -1;
        }
    }

    if (allocate_initial_states(f) < 0)
        return AVERROR(ENOMEM);

    for (i = 0; i < f->quant_table_count; i++)
        if (get_rac(c, state))
            for (j = 0; j < f->context_count[i]; j++)
                for (k = 0; k < CONTEXT_SIZE; k++) {
                    int pred = j ? f->initial_states[i][j - 1][k] : 128;
                    f->initial_states[i][j][k] =
                        (pred + get_symbol(c, state2[k], 1)) & 0xFF;
                }

    if (f->version > 2) {
        f->ec = get_symbol(c, state, 0);
    }

    if (f->version > 2) {
        unsigned v;
        v = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, f->avctx->extradata, f->avctx->extradata_size);
        if (v) {
            av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!\n", v);
            return AVERROR_INVALIDDATA;
        }
    }

    return 0;
}

static int read_header(FFV1Context *f)
{
    uint8_t state[CONTEXT_SIZE];
    int i, j, context_count = -1; //-1 to avoid warning
    RangeCoder *const c = &f->slice_context[0]->c;

    memset(state, 128, sizeof(state));

    if (f->version < 2) {
        unsigned v= get_symbol(c, state, 0);
        if (v >= 2) {
            av_log(f->avctx, AV_LOG_ERROR, "invalid version %d in ver01 header\n", v);
            return AVERROR_INVALIDDATA;
        }
        f->version = v;
        f->ac      = f->avctx->coder_type = get_symbol(c, state, 0);
        if (f->ac > 1)
            for (i = 1; i < 256; i++)
                f->state_transition[i] = get_symbol(c, state, 1) + c->one_state[i];
        f->colorspace = get_symbol(c, state, 0); // YUV cs type
        if (f->version > 0)
            f->avctx->bits_per_raw_sample = get_symbol(c, state, 0);
        f->chroma_planes  = get_rac(c, state);
        f->chroma_h_shift = get_symbol(c, state, 0);
        f->chroma_v_shift = get_symbol(c, state, 0);
        f->transparency   = get_rac(c, state);
        f->plane_count    = 2 + f->transparency;
    }

    if (f->colorspace == 0) {
        if (!f->transparency && !f->chroma_planes) {
            if (f->avctx->bits_per_raw_sample <= 8)
                f->avctx->pix_fmt = AV_PIX_FMT_GRAY8;
            else
                f->avctx->pix_fmt = AV_PIX_FMT_GRAY16;
        } else if (f->avctx->bits_per_raw_sample<=8 && !f->transparency) {
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P; break;
            case 0x01: f->avctx->pix_fmt = AV_PIX_FMT_YUV440P; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P; break;
            case 0x20: f->avctx->pix_fmt = AV_PIX_FMT_YUV411P; break;
            case 0x22: f->avctx->pix_fmt = AV_PIX_FMT_YUV410P; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        } else if (f->avctx->bits_per_raw_sample <= 8 && f->transparency) {
            switch(16*f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUVA444P; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUVA422P; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUVA420P; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        } else if (f->avctx->bits_per_raw_sample == 9) {
            f->packed_at_lsb = 1;
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P9; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P9; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P9; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        } else if (f->avctx->bits_per_raw_sample == 10) {
            f->packed_at_lsb = 1;
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P10; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P10; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P10; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        } else {
            switch(16 * f->chroma_h_shift + f->chroma_v_shift) {
            case 0x00: f->avctx->pix_fmt = AV_PIX_FMT_YUV444P16; break;
            case 0x10: f->avctx->pix_fmt = AV_PIX_FMT_YUV422P16; break;
            case 0x11: f->avctx->pix_fmt = AV_PIX_FMT_YUV420P16; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        }
    } else if (f->colorspace == 1) {
        if (f->chroma_h_shift || f->chroma_v_shift) {
            av_log(f->avctx, AV_LOG_ERROR,
                   "chroma subsampling not supported in this colorspace\n");
            return -1;
        }
        if (     f->avctx->bits_per_raw_sample ==  9)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP9;
        else if (f->avctx->bits_per_raw_sample == 10)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP10;
        else if (f->avctx->bits_per_raw_sample == 12)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP12;
        else if (f->avctx->bits_per_raw_sample == 14)
            f->avctx->pix_fmt = AV_PIX_FMT_GBRP14;
        else
        if (f->transparency) f->avctx->pix_fmt = AV_PIX_FMT_RGB32;
        else                 f->avctx->pix_fmt = AV_PIX_FMT_0RGB32;
    } else {
        av_log(f->avctx, AV_LOG_ERROR, "colorspace not supported\n");
        return -1;
    }

    av_dlog(f->avctx, "%d %d %d\n",
            f->chroma_h_shift, f->chroma_v_shift, f->avctx->pix_fmt);

    if (f->version < 2) {
        context_count = read_quant_tables(c, f->quant_table);
        if (context_count < 0) {
            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
            return -1;
        }
    } else if (f->version < 3) {
        f->slice_count = get_symbol(c, state, 0);
    } else {
        const uint8_t *p = c->bytestream_end;
        for (f->slice_count = 0; f->slice_count < MAX_SLICES && 3 < p - c->bytestream_start; f->slice_count++) {
            int trailer = 3 + 5*!!f->ec;
            int size = AV_RB24(p-trailer);
            if (size + trailer > p - c->bytestream_start)
                break;
            p -= size + trailer;
        }
    }
    if (f->slice_count > (unsigned)MAX_SLICES || f->slice_count <= 0) {
        av_log(f->avctx, AV_LOG_ERROR, "slice count %d is invalid\n", f->slice_count);
        return -1;
    }

    for (j = 0; j < f->slice_count; j++) {
        FFV1Context *fs = f->slice_context[j];
        fs->ac = f->ac;
        fs->packed_at_lsb = f->packed_at_lsb;

        fs->slice_damaged = 0;

        if (f->version == 2) {
            fs->slice_x      =  get_symbol(c, state, 0)      * f->width ;
            fs->slice_y      =  get_symbol(c, state, 0)      * f->height;
            fs->slice_width  = (get_symbol(c, state, 0) + 1) * f->width  + fs->slice_x;
            fs->slice_height = (get_symbol(c, state, 0) + 1) * f->height + fs->slice_y;

            fs->slice_x     /= f->num_h_slices;
            fs->slice_y     /= f->num_v_slices;
            fs->slice_width  = fs->slice_width  / f->num_h_slices - fs->slice_x;
            fs->slice_height = fs->slice_height / f->num_v_slices - fs->slice_y;
            if ((unsigned)fs->slice_width  > f->width ||
                (unsigned)fs->slice_height > f->height)
                return -1;
            if ((unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width ||
                (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
                return -1;
        }

        for (i = 0; i < f->plane_count; i++) {
            PlaneContext *const p = &fs->plane[i];

            if (f->version == 2) {
                int idx = get_symbol(c, state, 0);
                if (idx > (unsigned)f->quant_table_count) {
                    av_log(f->avctx, AV_LOG_ERROR,
                           "quant_table_index out of range\n");
                    return -1;
                }
                p->quant_table_index = idx;
                memcpy(p->quant_table, f->quant_tables[idx],
                       sizeof(p->quant_table));
                context_count = f->context_count[idx];
            } else {
                memcpy(p->quant_table, f->quant_table, sizeof(p->quant_table));
            }

            if (f->version <= 2) {
                av_assert0(context_count >= 0);
                if (p->context_count < context_count) {
                    av_freep(&p->state);
                    av_freep(&p->vlc_state);
                }
                p->context_count = context_count;
            }
        }
    }
    return 0;
}

static av_cold int decode_init(AVCodecContext *avctx)
{
    FFV1Context *f = avctx->priv_data;

    common_init(avctx);

    if (avctx->extradata && read_extra_header(f) < 0)
        return -1;

    if (init_slice_contexts(f) < 0)
        return -1;

    return 0;
}

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
{
    const uint8_t *buf  = avpkt->data;
    int buf_size        = avpkt->size;
    FFV1Context *f      = avctx->priv_data;
    RangeCoder *const c = &f->slice_context[0]->c;
    AVFrame *const p    = &f->picture;
    int i;
    uint8_t keystate = 128;
    const uint8_t *buf_p;

    AVFrame *picture = data;

    /* release previously stored data */
    if (p->data[0])
        avctx->release_buffer(avctx, p);

    ff_init_range_decoder(c, buf, buf_size);
    ff_build_rac_states(c, 0.05 * (1LL << 32), 256 - 8);

    p->pict_type = AV_PICTURE_TYPE_I; // FIXME: I vs. P
    if (get_rac(c, &keystate)) {
        p->key_frame = 1;
        f->key_frame_ok = 0;
        if (read_header(f) < 0)
            return -1;
        f->key_frame_ok = 1;
    } else {
        if (!f->key_frame_ok) {
            av_log(avctx, AV_LOG_ERROR, "Cant decode non keyframe without valid keyframe\n");
            return AVERROR_INVALIDDATA;
        }
        p->key_frame= 0;
    }

    p->reference = 3; //for error concealment
    if (avctx->get_buffer(avctx, p) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    if (avctx->debug&FF_DEBUG_PICT_INFO)
        av_log(avctx, AV_LOG_DEBUG, "ver:%d keyframe:%d coder:%d ec:%d slices:%d bps:%d\n",
               f->version, p->key_frame, f->ac, f->ec, f->slice_count, f->avctx->bits_per_raw_sample);

    buf_p = buf + buf_size;
    for (i = f->slice_count - 1; i >= 0; i--) {
        FFV1Context *fs = f->slice_context[i];
        int trailer = 3 + 5*!!f->ec;
        int v;

        if (i || f->version>2) v = AV_RB24(buf_p-trailer)+trailer;
        else                   v = buf_p - c->bytestream_start;
        if (buf_p - c->bytestream_start < v) {
            av_log(avctx, AV_LOG_ERROR, "Slice pointer chain broken\n");
            return -1;
        }
        buf_p -= v;

        if (f->ec) {
            unsigned crc = av_crc(av_crc_get_table(AV_CRC_32_IEEE), 0, buf_p, v);
            if (crc) {
                int64_t ts = avpkt->pts != AV_NOPTS_VALUE ? avpkt->pts : avpkt->dts;
                av_log(f->avctx, AV_LOG_ERROR, "CRC mismatch %X!", crc);
                if (ts != AV_NOPTS_VALUE && avctx->pkt_timebase.num) {
                    av_log(f->avctx, AV_LOG_ERROR, "at %f seconds\n", ts*av_q2d(avctx->pkt_timebase));
                } else if (ts != AV_NOPTS_VALUE) {
                    av_log(f->avctx, AV_LOG_ERROR, "at %"PRId64"\n", ts);
                } else {
                    av_log(f->avctx, AV_LOG_ERROR, "\n");
                }
                fs->slice_damaged = 1;
            }
        }

        if (i) {
            ff_init_range_decoder(&fs->c, buf_p, v);
        } else
            fs->c.bytestream_end = (uint8_t *)(buf_p + v);
    }

    avctx->execute(avctx, decode_slice, &f->slice_context[0], NULL, f->slice_count, sizeof(void*));

    for (i=f->slice_count-1; i>=0; i--) {
        FFV1Context *fs= f->slice_context[i];
        int j;
        if (fs->slice_damaged && f->last_picture.data[0]) {
            uint8_t *dst[4], *src[4];
            for (j=0; j<4; j++) {
                int sh = (j==1 || j==2) ? f->chroma_h_shift : 0;
                int sv = (j==1 || j==2) ? f->chroma_v_shift : 0;
                dst[j] = f->picture     .data[j] + f->picture     .linesize[j]*
                         (fs->slice_y>>sv) + (fs->slice_x>>sh);
                src[j] = f->last_picture.data[j] + f->last_picture.linesize[j]*
                         (fs->slice_y>>sv) + (fs->slice_x>>sh);
            }
            av_image_copy(dst, f->picture.linesize, (const uint8_t **)src, f->last_picture.linesize,
                          avctx->pix_fmt, fs->slice_width, fs->slice_height);
        }
    }

    f->picture_number++;

    *picture   = *p;
    *data_size = sizeof(AVFrame);

    FFSWAP(AVFrame, f->picture, f->last_picture);

    return buf_size;
}

AVCodec ff_ffv1_decoder = {
    .name           = "ffv1",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_FFV1,
    .priv_data_size = sizeof(FFV1Context),
    .init           = decode_init,
    .close          = common_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/ |
                      CODEC_CAP_SLICE_THREADS,
    .long_name      = NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
};

#if CONFIG_FFV1_ENCODER

#define OFFSET(x) offsetof(FFV1Context, x)
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    { "slicecrc",        "Protect slices with CRCs",               OFFSET(ec),              AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, VE},
{NULL}
};

static const AVClass class = {
    .class_name = "ffv1 encoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

static const AVCodecDefault ffv1_defaults[] = {
    { "coder",                "-1" },
    { NULL },
};

AVCodec ff_ffv1_encoder = {
    .name           = "ffv1",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_FFV1,
    .priv_data_size = sizeof(FFV1Context),
    .init           = encode_init,
    .encode2        = encode_frame,
    .close          = common_end,
    .capabilities   = CODEC_CAP_SLICE_THREADS,
    .defaults       = ffv1_defaults,
    .pix_fmts       = (const enum AVPixelFormat[]) {
        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV444P,
        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P,
        AV_PIX_FMT_YUV410P, AV_PIX_FMT_0RGB32, AV_PIX_FMT_RGB32, AV_PIX_FMT_YUV420P16,
        AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16, AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV422P9,
        AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
        AV_PIX_FMT_GRAY16, AV_PIX_FMT_GRAY8, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
        AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14,
        AV_PIX_FMT_NONE
    },
    .long_name      = NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
    .priv_class     = &class,
};
#endif