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FFmpeg/libavcodec/vc1_pred.c

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  1. /*

  2.  * VC-1 and WMV3 decoder

  3.  * Copyright (c) 2011 Mashiat Sarker Shakkhar

  4.  * Copyright (c) 2006-2007 Konstantin Shishkov

  5.  * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer

  6.  *

  7.  * This file is part of FFmpeg.

  8.  *

  9.  * FFmpeg is free software; you can redistribute it and/or

  10.  * modify it under the terms of the GNU Lesser General Public

  11.  * License as published by the Free Software Foundation; either

  12.  * version 2.1 of the License, or (at your option) any later version.

  13.  *

  14.  * FFmpeg is distributed in the hope that it will be useful,

  15.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  16.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  17.  * Lesser General Public License for more details.

  18.  *

  19.  * You should have received a copy of the GNU Lesser General Public

  20.  * License along with FFmpeg; if not, write to the Free Software

  21.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  22.  */

  23. 

  24. /**

  25.  * @file

  26.  * VC-1 and WMV3 block decoding routines

  27.  */

  28. 

  29. #include "mathops.h"

  30. #include "mpegutils.h"

  31. #include "mpegvideo.h"

  32. #include "vc1.h"

  33. #include "vc1_pred.h"

  34. #include "vc1data.h"

  35. 

  36. static av_always_inline int scaleforsame_x(VC1Context *v, int n /* MV */, int dir)

  37. {

  38.     int scaledvalue, refdist;

  39.     int scalesame1, scalesame2;

  40.     int scalezone1_x, zone1offset_x;

  41.     int table_index = dir ^ v->second_field;

  42. 

  43.     if (v->s.pict_type != AV_PICTURE_TYPE_B)

  44.         refdist = v->refdist;

  45.     else

  46.         refdist = dir ? v->brfd : v->frfd;

  47.     if (refdist > 3)

  48.         refdist = 3;

  49.     scalesame1    = ff_vc1_field_mvpred_scales[table_index][1][refdist];

  50.     scalesame2    = ff_vc1_field_mvpred_scales[table_index][2][refdist];

  51.     scalezone1_x  = ff_vc1_field_mvpred_scales[table_index][3][refdist];

  52.     zone1offset_x = ff_vc1_field_mvpred_scales[table_index][5][refdist];

  53. 

  54.     if (FFABS(n) > 255)

  55.         scaledvalue = n;

  56.     else {

  57.         if (FFABS(n) < scalezone1_x)

  58.             scaledvalue = (n * scalesame1) >> 8;

  59.         else {

  60.             if (n < 0)

  61.                 scaledvalue = ((n * scalesame2) >> 8) - zone1offset_x;

  62.             else

  63.                 scaledvalue = ((n * scalesame2) >> 8) + zone1offset_x;

  64.         }

  65.     }

  66.     return av_clip(scaledvalue, -v->range_x, v->range_x - 1);

  67. }

  68. 

  69. static av_always_inline int scaleforsame_y(VC1Context *v, int i, int n /* MV */, int dir)

  70. {

  71.     int scaledvalue, refdist;

  72.     int scalesame1, scalesame2;

  73.     int scalezone1_y, zone1offset_y;

  74.     int table_index = dir ^ v->second_field;

  75. 

  76.     if (v->s.pict_type != AV_PICTURE_TYPE_B)

  77.         refdist = v->refdist;

  78.     else

  79.         refdist = dir ? v->brfd : v->frfd;

  80.     if (refdist > 3)

  81.         refdist = 3;

  82.     scalesame1    = ff_vc1_field_mvpred_scales[table_index][1][refdist];

  83.     scalesame2    = ff_vc1_field_mvpred_scales[table_index][2][refdist];

  84.     scalezone1_y  = ff_vc1_field_mvpred_scales[table_index][4][refdist];

  85.     zone1offset_y = ff_vc1_field_mvpred_scales[table_index][6][refdist];

  86. 

  87.     if (FFABS(n) > 63)

  88.         scaledvalue = n;

  89.     else {

  90.         if (FFABS(n) < scalezone1_y)

  91.             scaledvalue = (n * scalesame1) >> 8;

  92.         else {

  93.             if (n < 0)

  94.                 scaledvalue = ((n * scalesame2) >> 8) - zone1offset_y;

  95.             else

  96.                 scaledvalue = ((n * scalesame2) >> 8) + zone1offset_y;

  97.         }

  98.     }

  99. 

  100.     if (v->cur_field_type && !v->ref_field_type[dir])

  101.         return av_clip(scaledvalue, -v->range_y / 2 + 1, v->range_y / 2);

  102.     else

  103.         return av_clip(scaledvalue, -v->range_y / 2, v->range_y / 2 - 1);

  104. }

  105. 

  106. static av_always_inline int scaleforopp_x(VC1Context *v, int n /* MV */)

  107. {

  108.     int scalezone1_x, zone1offset_x;

  109.     int scaleopp1, scaleopp2, brfd;

  110.     int scaledvalue;

  111. 

  112.     brfd = FFMIN(v->brfd, 3);

  113.     scalezone1_x  = ff_vc1_b_field_mvpred_scales[3][brfd];

  114.     zone1offset_x = ff_vc1_b_field_mvpred_scales[5][brfd];

  115.     scaleopp1     = ff_vc1_b_field_mvpred_scales[1][brfd];

  116.     scaleopp2     = ff_vc1_b_field_mvpred_scales[2][brfd];

  117. 

  118.     if (FFABS(n) > 255)

  119.         scaledvalue = n;

  120.     else {

  121.         if (FFABS(n) < scalezone1_x)

  122.             scaledvalue = (n * scaleopp1) >> 8;

  123.         else {

  124.             if (n < 0)

  125.                 scaledvalue = ((n * scaleopp2) >> 8) - zone1offset_x;

  126.             else

  127.                 scaledvalue = ((n * scaleopp2) >> 8) + zone1offset_x;

  128.         }

  129.     }

  130.     return av_clip(scaledvalue, -v->range_x, v->range_x - 1);

  131. }

  132. 

  133. static av_always_inline int scaleforopp_y(VC1Context *v, int n /* MV */, int dir)

  134. {

  135.     int scalezone1_y, zone1offset_y;

  136.     int scaleopp1, scaleopp2, brfd;

  137.     int scaledvalue;

  138. 

  139.     brfd = FFMIN(v->brfd, 3);

  140.     scalezone1_y  = ff_vc1_b_field_mvpred_scales[4][brfd];

  141.     zone1offset_y = ff_vc1_b_field_mvpred_scales[6][brfd];

  142.     scaleopp1     = ff_vc1_b_field_mvpred_scales[1][brfd];

  143.     scaleopp2     = ff_vc1_b_field_mvpred_scales[2][brfd];

  144. 

  145.     if (FFABS(n) > 63)

  146.         scaledvalue = n;

  147.     else {

  148.         if (FFABS(n) < scalezone1_y)

  149.             scaledvalue = (n * scaleopp1) >> 8;

  150.         else {

  151.             if (n < 0)

  152.                 scaledvalue = ((n * scaleopp2) >> 8) - zone1offset_y;

  153.             else

  154.                 scaledvalue = ((n * scaleopp2) >> 8) + zone1offset_y;

  155.         }

  156.     }

  157.     if (v->cur_field_type && !v->ref_field_type[dir]) {

  158.         return av_clip(scaledvalue, -v->range_y / 2 + 1, v->range_y / 2);

  159.     } else {

  160.         return av_clip(scaledvalue, -v->range_y / 2, v->range_y / 2 - 1);

  161.     }

  162. }

  163. 

  164. static av_always_inline int scaleforsame(VC1Context *v, int i, int n /* MV */,

  165.                                          int dim, int dir)

  166. {

  167.     int brfd, scalesame;

  168.     int hpel = 1 - v->s.quarter_sample;

  169. 

  170.     n >>= hpel;

  171.     if (v->s.pict_type != AV_PICTURE_TYPE_B || v->second_field || !dir) {

  172.         if (dim)

  173.             n = scaleforsame_y(v, i, n, dir) << hpel;

  174.         else

  175.             n = scaleforsame_x(v, n, dir) << hpel;

  176.         return n;

  177.     }

  178.     brfd      = FFMIN(v->brfd, 3);

  179.     scalesame = ff_vc1_b_field_mvpred_scales[0][brfd];

  180. 

  181.     n = (n * scalesame >> 8) << hpel;

  182.     return n;

  183. }

  184. 

  185. static av_always_inline int scaleforopp(VC1Context *v, int n /* MV */,

  186.                                         int dim, int dir)

  187. {

  188.     int refdist, scaleopp;

  189.     int hpel = 1 - v->s.quarter_sample;

  190. 

  191.     n >>= hpel;

  192.     if (v->s.pict_type == AV_PICTURE_TYPE_B && !v->second_field && dir == 1) {

  193.         if (dim)

  194.             n = scaleforopp_y(v, n, dir) << hpel;

  195.         else

  196.             n = scaleforopp_x(v, n) << hpel;

  197.         return n;

  198.     }

  199.     if (v->s.pict_type != AV_PICTURE_TYPE_B)

  200.         refdist = FFMIN(v->refdist, 3);

  201.     else

  202.         refdist = dir ? v->brfd : v->frfd;

  203.     scaleopp = ff_vc1_field_mvpred_scales[dir ^ v->second_field][0][refdist];

  204. 

  205.     n = (n * scaleopp >> 8) << hpel;

  206.     return n;

  207. }

  208. 

  209. /** Predict and set motion vector

  210.  */

  211. void ff_vc1_pred_mv(VC1Context *v, int n, int dmv_x, int dmv_y,

  212.                     int mv1, int r_x, int r_y, uint8_t* is_intra,

  213.                     int pred_flag, int dir)

  214. {

  215.     MpegEncContext *s = &v->s;

  216.     int xy, wrap, off = 0;

  217.     int16_t *A, *B, *C;

  218.     int px, py;

  219.     int sum;

  220.     int mixedmv_pic, num_samefield = 0, num_oppfield = 0;

  221.     int opposite, a_f, b_f, c_f;

  222.     int16_t field_predA[2];

  223.     int16_t field_predB[2];

  224.     int16_t field_predC[2];

  225.     int a_valid, b_valid, c_valid;

  226.     int hybridmv_thresh, y_bias = 0;

  227. 

  228.     if (v->mv_mode == MV_PMODE_MIXED_MV ||

  229.         ((v->mv_mode == MV_PMODE_INTENSITY_COMP) && (v->mv_mode2 == MV_PMODE_MIXED_MV)))

  230.         mixedmv_pic = 1;

  231.     else

  232.         mixedmv_pic = 0;

  233.     /* scale MV difference to be quad-pel */

  234.     dmv_x <<= 1 - s->quarter_sample;

  235.     dmv_y <<= 1 - s->quarter_sample;

  236. 

  237.     wrap = s->b8_stride;

  238.     xy   = s->block_index[n];

  239. 

  240.     if (s->mb_intra) {

  241.         s->mv[0][n][0] = s->current_picture.motion_val[0][xy + v->blocks_off][0] = 0;

  242.         s->mv[0][n][1] = s->current_picture.motion_val[0][xy + v->blocks_off][1] = 0;

  243.         s->current_picture.motion_val[1][xy + v->blocks_off][0] = 0;

  244.         s->current_picture.motion_val[1][xy + v->blocks_off][1] = 0;

  245.         if (mv1) { /* duplicate motion data for 1-MV block */

  246.             s->current_picture.motion_val[0][xy + 1 + v->blocks_off][0]        = 0;

  247.             s->current_picture.motion_val[0][xy + 1 + v->blocks_off][1]        = 0;

  248.             s->current_picture.motion_val[0][xy + wrap + v->blocks_off][0]     = 0;

  249.             s->current_picture.motion_val[0][xy + wrap + v->blocks_off][1]     = 0;

  250.             s->current_picture.motion_val[0][xy + wrap + 1 + v->blocks_off][0] = 0;

  251.             s->current_picture.motion_val[0][xy + wrap + 1 + v->blocks_off][1] = 0;

  252.             v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;

  253.             s->current_picture.motion_val[1][xy + 1 + v->blocks_off][0]        = 0;

  254.             s->current_picture.motion_val[1][xy + 1 + v->blocks_off][1]        = 0;

  255.             s->current_picture.motion_val[1][xy + wrap][0]                     = 0;

  256.             s->current_picture.motion_val[1][xy + wrap + v->blocks_off][1]     = 0;

  257.             s->current_picture.motion_val[1][xy + wrap + 1 + v->blocks_off][0] = 0;

  258.             s->current_picture.motion_val[1][xy + wrap + 1 + v->blocks_off][1] = 0;

  259.         }

  260.         return;

  261.     }

  262. 

  263.     C = s->current_picture.motion_val[dir][xy -    1 + v->blocks_off];

  264.     A = s->current_picture.motion_val[dir][xy - wrap + v->blocks_off];

  265.     if (mv1) {

  266.         if (v->field_mode && mixedmv_pic)

  267.             off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;

  268.         else

  269.             off = (s->mb_x == (s->mb_width - 1)) ? -1 : 2;

  270.     } else {

  271.         //in 4-MV mode different blocks have different B predictor position

  272.         switch (n) {

  273.         case 0:

  274.             off = (s->mb_x > 0) ? -1 : 1;

  275.             break;

  276.         case 1:

  277.             off = (s->mb_x == (s->mb_width - 1)) ? -1 : 1;

  278.             break;

  279.         case 2:

  280.             off = 1;

  281.             break;

  282.         case 3:

  283.             off = -1;

  284.         }

  285.     }

  286.     B = s->current_picture.motion_val[dir][xy - wrap + off + v->blocks_off];

  287. 

  288.     a_valid = !s->first_slice_line || (n == 2 || n == 3);

  289.     b_valid = a_valid && (s->mb_width > 1);

  290.     c_valid = s->mb_x || (n == 1 || n == 3);

  291.     if (v->field_mode) {

  292.         a_valid = a_valid && !is_intra[xy - wrap];

  293.         b_valid = b_valid && !is_intra[xy - wrap + off];

  294.         c_valid = c_valid && !is_intra[xy - 1];

  295.     }

  296. 

  297.     if (a_valid) {

  298.         a_f = v->mv_f[dir][xy - wrap + v->blocks_off];

  299.         num_oppfield  += a_f;

  300.         num_samefield += 1 - a_f;

  301.         field_predA[0] = A[0];

  302.         field_predA[1] = A[1];

  303.     } else {

  304.         field_predA[0] = field_predA[1] = 0;

  305.         a_f = 0;

  306.     }

  307.     if (b_valid) {

  308.         b_f = v->mv_f[dir][xy - wrap + off + v->blocks_off];

  309.         num_oppfield  += b_f;

  310.         num_samefield += 1 - b_f;

  311.         field_predB[0] = B[0];

  312.         field_predB[1] = B[1];

  313.     } else {

  314.         field_predB[0] = field_predB[1] = 0;

  315.         b_f = 0;

  316.     }

  317.     if (c_valid) {

  318.         c_f = v->mv_f[dir][xy - 1 + v->blocks_off];

  319.         num_oppfield  += c_f;

  320.         num_samefield += 1 - c_f;

  321.         field_predC[0] = C[0];

  322.         field_predC[1] = C[1];

  323.     } else {

  324.         field_predC[0] = field_predC[1] = 0;

  325.         c_f = 0;

  326.     }

  327. 

  328.     if (v->field_mode) {

  329.         if (!v->numref)

  330.             // REFFIELD determines if the last field or the second-last field is

  331.             // to be used as reference

  332.             opposite = 1 - v->reffield;

  333.         else {

  334.             if (num_samefield <= num_oppfield)

  335.                 opposite = 1 - pred_flag;

  336.             else

  337.                 opposite = pred_flag;

  338.         }

  339.     } else

  340.         opposite = 0;

  341.     if (opposite) {

  342.         if (a_valid && !a_f) {

  343.             field_predA[0] = scaleforopp(v, field_predA[0], 0, dir);

  344.             field_predA[1] = scaleforopp(v, field_predA[1], 1, dir);

  345.         }

  346.         if (b_valid && !b_f) {

  347.             field_predB[0] = scaleforopp(v, field_predB[0], 0, dir);

  348.             field_predB[1] = scaleforopp(v, field_predB[1], 1, dir);

  349.         }

  350.         if (c_valid && !c_f) {

  351.             field_predC[0] = scaleforopp(v, field_predC[0], 0, dir);

  352.             field_predC[1] = scaleforopp(v, field_predC[1], 1, dir);

  353.         }

  354.         v->mv_f[dir][xy + v->blocks_off] = 1;

  355.         v->ref_field_type[dir] = !v->cur_field_type;

  356.     } else {

  357.         if (a_valid && a_f) {

  358.             field_predA[0] = scaleforsame(v, n, field_predA[0], 0, dir);

  359.             field_predA[1] = scaleforsame(v, n, field_predA[1], 1, dir);

  360.         }

  361.         if (b_valid && b_f) {

  362.             field_predB[0] = scaleforsame(v, n, field_predB[0], 0, dir);

  363.             field_predB[1] = scaleforsame(v, n, field_predB[1], 1, dir);

  364.         }

  365.         if (c_valid && c_f) {

  366.             field_predC[0] = scaleforsame(v, n, field_predC[0], 0, dir);

  367.             field_predC[1] = scaleforsame(v, n, field_predC[1], 1, dir);

  368.         }

  369.         v->mv_f[dir][xy + v->blocks_off] = 0;

  370.         v->ref_field_type[dir] = v->cur_field_type;

  371.     }

  372. 

  373.     if (a_valid) {

  374.         px = field_predA[0];

  375.         py = field_predA[1];

  376.     } else if (c_valid) {

  377.         px = field_predC[0];

  378.         py = field_predC[1];

  379.     } else if (b_valid) {

  380.         px = field_predB[0];

  381.         py = field_predB[1];

  382.     } else {

  383.         px = 0;

  384.         py = 0;

  385.     }

  386. 

  387.     if (num_samefield + num_oppfield > 1) {

  388.         px = mid_pred(field_predA[0], field_predB[0], field_predC[0]);

  389.         py = mid_pred(field_predA[1], field_predB[1], field_predC[1]);

  390.     }

  391. 

  392.     /* Pullback MV as specified in 8.3.5.3.4 */

  393.     if (!v->field_mode) {

  394.         int qx, qy, X, Y;

  395.         int MV = mv1 ? -60 : -28;

  396.         qx = (s->mb_x << 6) + ((n == 1 || n == 3) ? 32 : 0);

  397.         qy = (s->mb_y << 6) + ((n == 2 || n == 3) ? 32 : 0);

  398.         X  = (s->mb_width  << 6) - 4;

  399.         Y  = (s->mb_height << 6) - 4;

  400.         if (qx + px < MV) px = MV - qx;

  401.         if (qy + py < MV) py = MV - qy;

  402.         if (qx + px > X) px = X - qx;

  403.         if (qy + py > Y) py = Y - qy;

  404.     }

  405. 

  406.     if (!v->field_mode || s->pict_type != AV_PICTURE_TYPE_B) {

  407.         /* Calculate hybrid prediction as specified in 8.3.5.3.5 (also 10.3.5.4.3.5) */

  408.         hybridmv_thresh = 32;

  409.         if (a_valid && c_valid) {

  410.             if (is_intra[xy - wrap])

  411.                 sum = FFABS(px) + FFABS(py);

  412.             else

  413.                 sum = FFABS(px - field_predA[0]) + FFABS(py - field_predA[1]);

  414.             if (sum > hybridmv_thresh) {

  415.                 if (get_bits1(&s->gb)) {     // read HYBRIDPRED bit

  416.                     px = field_predA[0];

  417.                     py = field_predA[1];

  418.                 } else {

  419.                     px = field_predC[0];

  420.                     py = field_predC[1];

  421.                 }

  422.             } else {

  423.                 if (is_intra[xy - 1])

  424.                     sum = FFABS(px) + FFABS(py);

  425.                 else

  426.                     sum = FFABS(px - field_predC[0]) + FFABS(py - field_predC[1]);

  427.                 if (sum > hybridmv_thresh) {

  428.                     if (get_bits1(&s->gb)) {

  429.                         px = field_predA[0];

  430.                         py = field_predA[1];

  431.                     } else {

  432.                         px = field_predC[0];

  433.                         py = field_predC[1];

  434.                     }

  435.                 }

  436.             }

  437.         }

  438.     }

  439. 

  440.     if (v->field_mode && v->numref)

  441.         r_y >>= 1;

  442.     if (v->field_mode && v->cur_field_type && v->ref_field_type[dir] == 0)

  443.         y_bias = 1;

  444.     /* store MV using signed modulus of MV range defined in 4.11 */

  445.     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;

  446.     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;

  447.     if (mv1) { /* duplicate motion data for 1-MV block */

  448.         s->current_picture.motion_val[dir][xy +    1 +     v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];

  449.         s->current_picture.motion_val[dir][xy +    1 +     v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];

  450.         s->current_picture.motion_val[dir][xy + wrap +     v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];

  451.         s->current_picture.motion_val[dir][xy + wrap +     v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];

  452.         s->current_picture.motion_val[dir][xy + wrap + 1 + v->blocks_off][0] = s->current_picture.motion_val[dir][xy + v->blocks_off][0];

  453.         s->current_picture.motion_val[dir][xy + wrap + 1 + v->blocks_off][1] = s->current_picture.motion_val[dir][xy + v->blocks_off][1];

  454.         v->mv_f[dir][xy +    1 + v->blocks_off] = v->mv_f[dir][xy +            v->blocks_off];

  455.         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];

  456.     }

  457. }

  458. 

  459. /** Predict and set motion vector for interlaced frame picture MBs

  460.  */

  461. void ff_vc1_pred_mv_intfr(VC1Context *v, int n, int dmv_x, int dmv_y,

  462.                           int mvn, int r_x, int r_y, uint8_t* is_intra, int dir)

  463. {

  464.     MpegEncContext *s = &v->s;

  465.     int xy, wrap, off = 0;

  466.     int A[2], B[2], C[2];

  467.     int px = 0, py = 0;

  468.     int a_valid = 0, b_valid = 0, c_valid = 0;

  469.     int field_a, field_b, field_c; // 0: same, 1: opposit

  470.     int total_valid, num_samefield, num_oppfield;

  471.     int pos_c, pos_b, n_adj;

  472. 

  473.     wrap = s->b8_stride;

  474.     xy = s->block_index[n];

  475. 

  476.     if (s->mb_intra) {

  477.         s->mv[0][n][0] = s->current_picture.motion_val[0][xy][0] = 0;

  478.         s->mv[0][n][1] = s->current_picture.motion_val[0][xy][1] = 0;

  479.         s->current_picture.motion_val[1][xy][0] = 0;

  480.         s->current_picture.motion_val[1][xy][1] = 0;

  481.         if (mvn == 1) { /* duplicate motion data for 1-MV block */

  482.             s->current_picture.motion_val[0][xy + 1][0]        = 0;

  483.             s->current_picture.motion_val[0][xy + 1][1]        = 0;

  484.             s->current_picture.motion_val[0][xy + wrap][0]     = 0;

  485.             s->current_picture.motion_val[0][xy + wrap][1]     = 0;

  486.             s->current_picture.motion_val[0][xy + wrap + 1][0] = 0;

  487.             s->current_picture.motion_val[0][xy + wrap + 1][1] = 0;

  488.             v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;

  489.             s->current_picture.motion_val[1][xy + 1][0]        = 0;

  490.             s->current_picture.motion_val[1][xy + 1][1]        = 0;

  491.             s->current_picture.motion_val[1][xy + wrap][0]     = 0;

  492.             s->current_picture.motion_val[1][xy + wrap][1]     = 0;

  493.             s->current_picture.motion_val[1][xy + wrap + 1][0] = 0;

  494.             s->current_picture.motion_val[1][xy + wrap + 1][1] = 0;

  495.         }

  496.         return;

  497.     }

  498. 

  499.     off = ((n == 0) || (n == 1)) ? 1 : -1;

  500.     /* predict A */

  501.     if (s->mb_x || (n == 1) || (n == 3)) {

  502.         if ((v->blk_mv_type[xy]) // current block (MB) has a field MV

  503.             || (!v->blk_mv_type[xy] && !v->blk_mv_type[xy - 1])) { // or both have frame MV

  504.             A[0] = s->current_picture.motion_val[dir][xy - 1][0];

  505.             A[1] = s->current_picture.motion_val[dir][xy - 1][1];

  506.             a_valid = 1;

  507.         } else { // current block has frame mv and cand. has field MV (so average)

  508.             A[0] = (s->current_picture.motion_val[dir][xy - 1][0]

  509.                     + s->current_picture.motion_val[dir][xy - 1 + off * wrap][0] + 1) >> 1;

  510.             A[1] = (s->current_picture.motion_val[dir][xy - 1][1]

  511.                     + s->current_picture.motion_val[dir][xy - 1 + off * wrap][1] + 1) >> 1;

  512.             a_valid = 1;

  513.         }

  514.         if (!(n & 1) && v->is_intra[s->mb_x - 1]) {

  515.             a_valid = 0;

  516.             A[0] = A[1] = 0;

  517.         }

  518.     } else

  519.         A[0] = A[1] = 0;

  520.     /* Predict B and C */

  521.     B[0] = B[1] = C[0] = C[1] = 0;

  522.     if (n == 0 || n == 1 || v->blk_mv_type[xy]) {

  523.         if (!s->first_slice_line) {

  524.             if (!v->is_intra[s->mb_x - s->mb_stride]) {

  525.                 b_valid = 1;

  526.                 n_adj   = n | 2;

  527.                 pos_b   = s->block_index[n_adj] - 2 * wrap;

  528.                 if (v->blk_mv_type[pos_b] && v->blk_mv_type[xy]) {

  529.                     n_adj = (n & 2) | (n & 1);

  530.                 }

  531.                 B[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap][0];

  532.                 B[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap][1];

  533.                 if (v->blk_mv_type[pos_b] && !v->blk_mv_type[xy]) {

  534.                     B[0] = (B[0] + s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap][0] + 1) >> 1;

  535.                     B[1] = (B[1] + s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap][1] + 1) >> 1;

  536.                 }

  537.             }

  538.             if (s->mb_width > 1) {

  539.                 if (!v->is_intra[s->mb_x - s->mb_stride + 1]) {

  540.                     c_valid = 1;

  541.                     n_adj   = 2;

  542.                     pos_c   = s->block_index[2] - 2 * wrap + 2;

  543.                     if (v->blk_mv_type[pos_c] && v->blk_mv_type[xy]) {

  544.                         n_adj = n & 2;

  545.                     }

  546.                     C[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap + 2][0];

  547.                     C[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap + 2][1];

  548.                     if (v->blk_mv_type[pos_c] && !v->blk_mv_type[xy]) {

  549.                         C[0] = (1 + C[0] + (s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap + 2][0])) >> 1;

  550.                         C[1] = (1 + C[1] + (s->current_picture.motion_val[dir][s->block_index[n_adj ^ 2] - 2 * wrap + 2][1])) >> 1;

  551.                     }

  552.                     if (s->mb_x == s->mb_width - 1) {

  553.                         if (!v->is_intra[s->mb_x - s->mb_stride - 1]) {

  554.                             c_valid = 1;

  555.                             n_adj   = 3;

  556.                             pos_c   = s->block_index[3] - 2 * wrap - 2;

  557.                             if (v->blk_mv_type[pos_c] && v->blk_mv_type[xy]) {

  558.                                 n_adj = n | 1;

  559.                             }

  560.                             C[0] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap - 2][0];

  561.                             C[1] = s->current_picture.motion_val[dir][s->block_index[n_adj] - 2 * wrap - 2][1];

  562.                             if (v->blk_mv_type[pos_c] && !v->blk_mv_type[xy]) {

  563.                                 C[0] = (1 + C[0] + s->current_picture.motion_val[dir][s->block_index[1] - 2 * wrap - 2][0]) >> 1;

  564.                                 C[1] = (1 + C[1] + s->current_picture.motion_val[dir][s->block_index[1] - 2 * wrap - 2][1]) >> 1;

  565.                             }

  566.                         } else

  567.                             c_valid = 0;

  568.                     }

  569.                 }

  570.             }

  571.         }

  572.     } else {

  573.         pos_b   = s->block_index[1];

  574.         b_valid = 1;

  575.         B[0]    = s->current_picture.motion_val[dir][pos_b][0];

  576.         B[1]    = s->current_picture.motion_val[dir][pos_b][1];

  577.         pos_c   = s->block_index[0];

  578.         c_valid = 1;

  579.         C[0]    = s->current_picture.motion_val[dir][pos_c][0];

  580.         C[1]    = s->current_picture.motion_val[dir][pos_c][1];

  581.     }

  582. 

  583.     total_valid = a_valid + b_valid + c_valid;

  584.     // check if predictor A is out of bounds

  585.     if (!s->mb_x && !(n == 1 || n == 3)) {

  586.         A[0] = A[1] = 0;

  587.     }

  588.     // check if predictor B is out of bounds

  589.     if ((s->first_slice_line && v->blk_mv_type[xy]) || (s->first_slice_line && !(n & 2))) {

  590.         B[0] = B[1] = C[0] = C[1] = 0;

  591.     }

  592.     if (!v->blk_mv_type[xy]) {

  593.         if (s->mb_width == 1) {

  594.             px = B[0];

  595.             py = B[1];

  596.         } else {

  597.             if (total_valid >= 2) {

  598.                 px = mid_pred(A[0], B[0], C[0]);

  599.                 py = mid_pred(A[1], B[1], C[1]);

  600.             } else if (total_valid) {

  601.                 if      (a_valid) { px = A[0]; py = A[1]; }

  602.                 else if (b_valid) { px = B[0]; py = B[1]; }

  603.                 else              { px = C[0]; py = C[1]; }

  604.             }

  605.         }

  606.     } else {

  607.         if (a_valid)

  608.             field_a = (A[1] & 4) ? 1 : 0;

  609.         else

  610.             field_a = 0;

  611.         if (b_valid)

  612.             field_b = (B[1] & 4) ? 1 : 0;

  613.         else

  614.             field_b = 0;

  615.         if (c_valid)

  616.             field_c = (C[1] & 4) ? 1 : 0;

  617.         else

  618.             field_c = 0;

  619. 

  620.         num_oppfield  = field_a + field_b + field_c;

  621.         num_samefield = total_valid - num_oppfield;

  622.         if (total_valid == 3) {

  623.             if ((num_samefield == 3) || (num_oppfield == 3)) {

  624.                 px = mid_pred(A[0], B[0], C[0]);

  625.                 py = mid_pred(A[1], B[1], C[1]);

  626.             } else if (num_samefield >= num_oppfield) {

  627.                 /* take one MV from same field set depending on priority

  628.                 the check for B may not be necessary */

  629.                 px = !field_a ? A[0] : B[0];

  630.                 py = !field_a ? A[1] : B[1];

  631.             } else {

  632.                 px =  field_a ? A[0] : B[0];

  633.                 py =  field_a ? A[1] : B[1];

  634.             }

  635.         } else if (total_valid == 2) {

  636.             if (num_samefield >= num_oppfield) {

  637.                 if (!field_a && a_valid) {

  638.                     px = A[0];

  639.                     py = A[1];

  640.                 } else if (!field_b && b_valid) {

  641.                     px = B[0];

  642.                     py = B[1];

  643.                 } else /*if (c_valid)*/ {

  644.                     av_assert1(c_valid);

  645.                     px = C[0];

  646.                     py = C[1];

  647.                 }

  648.             } else {

  649.                 if (field_a && a_valid) {

  650.                     px = A[0];

  651.                     py = A[1];

  652.                 } else /*if (field_b && b_valid)*/ {

  653.                     av_assert1(field_b && b_valid);

  654.                     px = B[0];

  655.                     py = B[1];

  656.                 }

  657.             }

  658.         } else if (total_valid == 1) {

  659.             px = (a_valid) ? A[0] : ((b_valid) ? B[0] : C[0]);

  660.             py = (a_valid) ? A[1] : ((b_valid) ? B[1] : C[1]);

  661.         }

  662.     }

  663. 

  664.     /* store MV using signed modulus of MV range defined in 4.11 */

  665.     s->mv[dir][n][0] = s->current_picture.motion_val[dir][xy][0] = ((px + dmv_x + r_x) & ((r_x << 1) - 1)) - r_x;

  666.     s->mv[dir][n][1] = s->current_picture.motion_val[dir][xy][1] = ((py + dmv_y + r_y) & ((r_y << 1) - 1)) - r_y;

  667.     if (mvn == 1) { /* duplicate motion data for 1-MV block */

  668.         s->current_picture.motion_val[dir][xy +    1    ][0] = s->current_picture.motion_val[dir][xy][0];

  669.         s->current_picture.motion_val[dir][xy +    1    ][1] = s->current_picture.motion_val[dir][xy][1];

  670.         s->current_picture.motion_val[dir][xy + wrap    ][0] = s->current_picture.motion_val[dir][xy][0];

  671.         s->current_picture.motion_val[dir][xy + wrap    ][1] = s->current_picture.motion_val[dir][xy][1];

  672.         s->current_picture.motion_val[dir][xy + wrap + 1][0] = s->current_picture.motion_val[dir][xy][0];

  673.         s->current_picture.motion_val[dir][xy + wrap + 1][1] = s->current_picture.motion_val[dir][xy][1];

  674.     } else if (mvn == 2) { /* duplicate motion data for 2-Field MV block */

  675.         s->current_picture.motion_val[dir][xy + 1][0] = s->current_picture.motion_val[dir][xy][0];

  676.         s->current_picture.motion_val[dir][xy + 1][1] = s->current_picture.motion_val[dir][xy][1];

  677.         s->mv[dir][n + 1][0] = s->mv[dir][n][0];

  678.         s->mv[dir][n + 1][1] = s->mv[dir][n][1];

  679.     }

  680. }

  681. 

  682. void ff_vc1_pred_b_mv(VC1Context *v, int dmv_x[2], int dmv_y[2],

  683.                       int direct, int mvtype)

  684. {

  685.     MpegEncContext *s = &v->s;

  686.     int xy, wrap, off = 0;

  687.     int16_t *A, *B, *C;

  688.     int px, py;

  689.     int sum;

  690.     int r_x, r_y;

  691.     const uint8_t *is_intra = v->mb_type[0];

  692. 

  693.     av_assert0(!v->field_mode);

  694. 

  695.     r_x = v->range_x;

  696.     r_y = v->range_y;

  697.     /* scale MV difference to be quad-pel */

  698.     dmv_x[0] <<= 1 - s->quarter_sample;

  699.     dmv_y[0] <<= 1 - s->quarter_sample;

  700.     dmv_x[1] <<= 1 - s->quarter_sample;

  701.     dmv_y[1] <<= 1 - s->quarter_sample;

  702. 

  703.     wrap = s->b8_stride;

  704.     xy = s->block_index[0];

  705. 

  706.     if (s->mb_intra) {

  707.         s->current_picture.motion_val[0][xy][0] =

  708.         s->current_picture.motion_val[0][xy][1] =

  709.         s->current_picture.motion_val[1][xy][0] =

  710.         s->current_picture.motion_val[1][xy][1] = 0;

  711.         return;

  712.     }

  713.         if (direct && s->next_picture_ptr->field_picture)

  714.             av_log(s->avctx, AV_LOG_WARNING, "Mixed frame/field direct mode not supported\n");

  715. 

  716.         s->mv[0][0][0] = scale_mv(s->next_picture.motion_val[1][xy][0], v->bfraction, 0, s->quarter_sample);

  717.         s->mv[0][0][1] = scale_mv(s->next_picture.motion_val[1][xy][1], v->bfraction, 0, s->quarter_sample);

  718.         s->mv[1][0][0] = scale_mv(s->next_picture.motion_val[1][xy][0], v->bfraction, 1, s->quarter_sample);

  719.         s->mv[1][0][1] = scale_mv(s->next_picture.motion_val[1][xy][1], v->bfraction, 1, s->quarter_sample);

  720. 

  721.         /* Pullback predicted motion vectors as specified in 8.4.5.4 */

  722.         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));

  723.         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));

  724.         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));

  725.         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));

  726.     if (direct) {

  727.         s->current_picture.motion_val[0][xy][0] = s->mv[0][0][0];

  728.         s->current_picture.motion_val[0][xy][1] = s->mv[0][0][1];

  729.         s->current_picture.motion_val[1][xy][0] = s->mv[1][0][0];

  730.         s->current_picture.motion_val[1][xy][1] = s->mv[1][0][1];

  731.         return;

  732.     }

  733. 

  734.     if ((mvtype == BMV_TYPE_FORWARD) || (mvtype == BMV_TYPE_INTERPOLATED)) {

  735.         C   = s->current_picture.motion_val[0][xy - 2];

  736.         A   = s->current_picture.motion_val[0][xy - wrap * 2];

  737.         off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;

  738.         B   = s->current_picture.motion_val[0][xy - wrap * 2 + off];

  739. 

  740.         if (!s->mb_x) C[0] = C[1] = 0;

  741.         if (!s->first_slice_line) { // predictor A is not out of bounds

  742.             if (s->mb_width == 1) {

  743.                 px = A[0];

  744.                 py = A[1];

  745.             } else {

  746.                 px = mid_pred(A[0], B[0], C[0]);

  747.                 py = mid_pred(A[1], B[1], C[1]);

  748.             }

  749.         } else if (s->mb_x) { // predictor C is not out of bounds

  750.             px = C[0];

  751.             py = C[1];

  752.         } else {

  753.             px = py = 0;

  754.         }

  755.         /* Pullback MV as specified in 8.3.5.3.4 */

  756.         {

  757.             int qx, qy, X, Y;

  758.             int sh = v->profile < PROFILE_ADVANCED ? 5 : 6;

  759.             int MV = 4 - (1 << sh);

  760.             qx = (s->mb_x << sh);

  761.             qy = (s->mb_y << sh);

  762.             X  = (s->mb_width  << sh) - 4;

  763.             Y  = (s->mb_height << sh) - 4;

  764.             if (qx + px < MV) px = MV - qx;

  765.             if (qy + py < MV) py = MV - qy;

  766.             if (qx + px > X) px = X - qx;

  767.             if (qy + py > Y) py = Y - qy;

  768.         }

  769.         /* Calculate hybrid prediction as specified in 8.3.5.3.5 */

  770.         if (0 && !s->first_slice_line && s->mb_x) {

  771.             if (is_intra[xy - wrap])

  772.                 sum = FFABS(px) + FFABS(py);

  773.             else

  774.                 sum = FFABS(px - A[0]) + FFABS(py - A[1]);

  775.             if (sum > 32) {

  776.                 if (get_bits1(&s->gb)) {

  777.                     px = A[0];

  778.                     py = A[1];

  779.                 } else {

  780.                     px = C[0];

  781.                     py = C[1];

  782.                 }

  783.             } else {

  784.                 if (is_intra[xy - 2])

  785.                     sum = FFABS(px) + FFABS(py);

  786.                 else

  787.                     sum = FFABS(px - C[0]) + FFABS(py - C[1]);

  788.                 if (sum > 32) {

  789.                     if (get_bits1(&s->gb)) {

  790.                         px = A[0];

  791.                         py = A[1];

  792.                     } else {

  793.                         px = C[0];

  794.                         py = C[1];

  795.                     }

  796.                 }

  797.             }

  798.         }

  799.         /* store MV using signed modulus of MV range defined in 4.11 */

  800.         s->mv[0][0][0] = ((px + dmv_x[0] + r_x) & ((r_x << 1) - 1)) - r_x;

  801.         s->mv[0][0][1] = ((py + dmv_y[0] + r_y) & ((r_y << 1) - 1)) - r_y;

  802.     }

  803.     if ((mvtype == BMV_TYPE_BACKWARD) || (mvtype == BMV_TYPE_INTERPOLATED)) {

  804.         C   = s->current_picture.motion_val[1][xy - 2];

  805.         A   = s->current_picture.motion_val[1][xy - wrap * 2];

  806.         off = (s->mb_x == (s->mb_width - 1)) ? -2 : 2;

  807.         B   = s->current_picture.motion_val[1][xy - wrap * 2 + off];

  808. 

  809.         if (!s->mb_x)

  810.             C[0] = C[1] = 0;

  811.         if (!s->first_slice_line) { // predictor A is not out of bounds

  812.             if (s->mb_width == 1) {

  813.                 px = A[0];

  814.                 py = A[1];

  815.             } else {

  816.                 px = mid_pred(A[0], B[0], C[0]);

  817.                 py = mid_pred(A[1], B[1], C[1]);

  818.             }

  819.         } else if (s->mb_x) { // predictor C is not out of bounds

  820.             px = C[0];

  821.             py = C[1];

  822.         } else {

  823.             px = py = 0;

  824.         }

  825.         /* Pullback MV as specified in 8.3.5.3.4 */

  826.         {

  827.             int qx, qy, X, Y;

  828.             int sh = v->profile < PROFILE_ADVANCED ? 5 : 6;

  829.             int MV = 4 - (1 << sh);

  830.             qx = (s->mb_x << sh);

  831.             qy = (s->mb_y << sh);

  832.             X  = (s->mb_width  << sh) - 4;

  833.             Y  = (s->mb_height << sh) - 4;

  834.             if (qx + px < MV) px = MV - qx;

  835.             if (qy + py < MV) py = MV - qy;

  836.             if (qx + px > X) px = X - qx;

  837.             if (qy + py > Y) py = Y - qy;

  838.         }

  839.         /* Calculate hybrid prediction as specified in 8.3.5.3.5 */

  840.         if (0 && !s->first_slice_line && s->mb_x) {

  841.             if (is_intra[xy - wrap])

  842.                 sum = FFABS(px) + FFABS(py);

  843.             else

  844.                 sum = FFABS(px - A[0]) + FFABS(py - A[1]);

  845.             if (sum > 32) {

  846.                 if (get_bits1(&s->gb)) {

  847.                     px = A[0];

  848.                     py = A[1];

  849.                 } else {

  850.                     px = C[0];

  851.                     py = C[1];

  852.                 }

  853.             } else {

  854.                 if (is_intra[xy - 2])

  855.                     sum = FFABS(px) + FFABS(py);

  856.                 else

  857.                     sum = FFABS(px - C[0]) + FFABS(py - C[1]);

  858.                 if (sum > 32) {

  859.                     if (get_bits1(&s->gb)) {

  860.                         px = A[0];

  861.                         py = A[1];

  862.                     } else {

  863.                         px = C[0];

  864.                         py = C[1];

  865.                     }

  866.                 }

  867.             }

  868.         }

  869.         /* store MV using signed modulus of MV range defined in 4.11 */

  870. 

  871.         s->mv[1][0][0] = ((px + dmv_x[1] + r_x) & ((r_x << 1) - 1)) - r_x;

  872.         s->mv[1][0][1] = ((py + dmv_y[1] + r_y) & ((r_y << 1) - 1)) - r_y;

  873.     }

  874.     s->current_picture.motion_val[0][xy][0] = s->mv[0][0][0];

  875.     s->current_picture.motion_val[0][xy][1] = s->mv[0][0][1];

  876.     s->current_picture.motion_val[1][xy][0] = s->mv[1][0][0];

  877.     s->current_picture.motion_val[1][xy][1] = s->mv[1][0][1];

  878. }

  879. 

  880. void ff_vc1_pred_b_mv_intfi(VC1Context *v, int n, int *dmv_x, int *dmv_y,

  881.                             int mv1, int *pred_flag)

  882. {

  883.     int dir = (v->bmvtype == BMV_TYPE_BACKWARD) ? 1 : 0;

  884.     MpegEncContext *s = &v->s;

  885.     int mb_pos = s->mb_x + s->mb_y * s->mb_stride;

  886. 

  887.     if (v->bmvtype == BMV_TYPE_DIRECT) {

  888.         int total_opp, k, f;

  889.         if (s->next_picture.mb_type[mb_pos + v->mb_off] != MB_TYPE_INTRA) {

  890.             s->mv[0][0][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][0],

  891.                                       v->bfraction, 0, s->quarter_sample);

  892.             s->mv[0][0][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][1],

  893.                                       v->bfraction, 0, s->quarter_sample);

  894.             s->mv[1][0][0] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][0],

  895.                                       v->bfraction, 1, s->quarter_sample);

  896.             s->mv[1][0][1] = scale_mv(s->next_picture.motion_val[1][s->block_index[0] + v->blocks_off][1],

  897.                                       v->bfraction, 1, s->quarter_sample);

  898. 

  899.             total_opp = v->mv_f_next[0][s->block_index[0] + v->blocks_off]

  900.                       + v->mv_f_next[0][s->block_index[1] + v->blocks_off]

  901.                       + v->mv_f_next[0][s->block_index[2] + v->blocks_off]

  902.                       + v->mv_f_next[0][s->block_index[3] + v->blocks_off];

  903.             f = (total_opp > 2) ? 1 : 0;

  904.         } else {

  905.             s->mv[0][0][0] = s->mv[0][0][1] = 0;

  906.             s->mv[1][0][0] = s->mv[1][0][1] = 0;

  907.             f = 0;

  908.         }

  909.         v->ref_field_type[0] = v->ref_field_type[1] = v->cur_field_type ^ f;

  910.         for (k = 0; k < 4; k++) {

  911.             s->current_picture.motion_val[0][s->block_index[k] + v->blocks_off][0] = s->mv[0][0][0];

  912.             s->current_picture.motion_val[0][s->block_index[k] + v->blocks_off][1] = s->mv[0][0][1];

  913.             s->current_picture.motion_val[1][s->block_index[k] + v->blocks_off][0] = s->mv[1][0][0];

  914.             s->current_picture.motion_val[1][s->block_index[k] + v->blocks_off][1] = s->mv[1][0][1];

  915.             v->mv_f[0][s->block_index[k] + v->blocks_off] = f;

  916.             v->mv_f[1][s->block_index[k] + v->blocks_off] = f;

  917.         }

  918.         return;

  919.     }

  920.     if (v->bmvtype == BMV_TYPE_INTERPOLATED) {

  921.         ff_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);

  922.         ff_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);

  923.         return;

  924.     }

  925.     if (dir) { // backward

  926.         ff_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);

  927.         if (n == 3 || mv1) {

  928.             ff_vc1_pred_mv(v, 0, dmv_x[0], dmv_y[0],   1, v->range_x, v->range_y, v->mb_type[0], 0, 0);

  929.         }

  930.     } else { // forward

  931.         ff_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);

  932.         if (n == 3 || mv1) {

  933.             ff_vc1_pred_mv(v, 0, dmv_x[1], dmv_y[1],   1, v->range_x, v->range_y, v->mb_type[0], 0, 1);

  934.         }

  935.     }

  936. }