/*
  * H.26L/H.264/AVC/JVT/14496-10/... direct mb/block decoding
  * Copyright (c) 2003 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

  * H.264 / AVC / MPEG4 part10 direct mb/block decoding.
  * @author Michael Niedermayer <michaelni@gmx.at>
  */
 
 #include "internal.h"
 #include "avcodec.h"
 #include "h264.h"

 #include "mpegutils.h"

 #include "rectangle.h"

 #include "thread.h"

 
 #include <assert.h>
 

 static int get_scale_factor(H264SliceContext *sl,

                             int poc, int poc1, int i)

 {

     int poc0 = sl->ref_list[0][i].poc;

     int td = av_clip_int8(poc1 - poc0);

     if (td == 0 || sl->ref_list[0][i].parent->long_ref) {

         return 256;

     } else {

         int tb = av_clip_int8(poc - poc0);

         int tx = (16384 + (FFABS(td) >> 1)) / td;

         return av_clip_intp2((tb * tx + 32) >> 6, 10);

     }
 }
 

 void ff_h264_direct_dist_scale_factor(const H264Context *const h,

                                       H264SliceContext *sl)

 {

     const int poc  = FIELD_PICTURE(h) ? h->cur_pic_ptr->field_poc[h->picture_structure == PICT_BOTTOM_FIELD]
                                       : h->cur_pic_ptr->poc;

     const int poc1 = sl->ref_list[1][0].poc;

     int i, field;
 

     if (FRAME_MBAFF(h))

         for (field = 0; field < 2; field++) {

             const int poc  = h->cur_pic_ptr->field_poc[field];

             const int poc1 = sl->ref_list[1][0].parent->field_poc[field];

             for (i = 0; i < 2 * sl->ref_count[0]; i++)

                 sl->dist_scale_factor_field[field][i ^ field] =

                     get_scale_factor(sl, poc, poc1, i + 16);

         }
 

     for (i = 0; i < sl->ref_count[0]; i++)

         sl->dist_scale_factor[i] = get_scale_factor(sl, poc, poc1, i);

 }
 

 static void fill_colmap(const H264Context *h, H264SliceContext *sl,

                         int map[2][16 + 32], int list,

                         int field, int colfield, int mbafi)
 {

     H264Picture *const ref1 = sl->ref_list[1][0].parent;

     int j, old_ref, rfield;

     int start  = mbafi ? 16                       : 0;

     int end    = mbafi ? 16 + 2 * sl->ref_count[0] : sl->ref_count[0];

     int interl = mbafi || h->picture_structure != PICT_FRAME;

 
     /* bogus; fills in for missing frames */
     memset(map[list], 0, sizeof(map[list]));
 

     for (rfield = 0; rfield < 2; rfield++) {
         for (old_ref = 0; old_ref < ref1->ref_count[colfield][list]; old_ref++) {

             int poc = ref1->ref_poc[colfield][list][old_ref];
 

             if (!interl)

                 poc |= 3;

             // FIXME: store all MBAFF references so this is not needed
             else if (interl && (poc & 3) == 3)
                 poc = (poc & ~3) + rfield + 1;
 
             for (j = start; j < end; j++) {

                 if (4 * sl->ref_list[0][j].parent->frame_num +

                     (sl->ref_list[0][j].reference & 3) == poc) {

                     int cur_ref = mbafi ? (j - 16) ^ field : j;

                     if (ref1->mbaff)

                         map[list][2 * old_ref + (rfield ^ field) + 16] = cur_ref;
                     if (rfield == field || !interl)

                         map[list][old_ref] = cur_ref;
                     break;
                 }
             }
         }
     }
 }
 

 void ff_h264_direct_ref_list_init(const H264Context *const h, H264SliceContext *sl)

 {

     H264Ref *const ref1 = &sl->ref_list[1][0];

     H264Picture *const cur = h->cur_pic_ptr;

     int list, j, field;

     int sidx     = (h->picture_structure & 1) ^ 1;
     int ref1sidx = (ref1->reference      & 1) ^ 1;

     for (list = 0; list < sl->list_count; list++) {

         cur->ref_count[sidx][list] = sl->ref_count[list];
         for (j = 0; j < sl->ref_count[list]; j++)

             cur->ref_poc[sidx][list][j] = 4 * sl->ref_list[list][j].parent->frame_num +

                                           (sl->ref_list[list][j].reference & 3);

     }
 

     if (h->picture_structure == PICT_FRAME) {

         memcpy(cur->ref_count[1], cur->ref_count[0], sizeof(cur->ref_count[0]));

         memcpy(cur->ref_poc[1],   cur->ref_poc[0],   sizeof(cur->ref_poc[0]));

     }
 

     cur->mbaff = FRAME_MBAFF(h);

     sl->col_fieldoff = 0;

 
     if (sl->list_count != 2 || !sl->ref_count[1])
         return;
 

     if (h->picture_structure == PICT_FRAME) {
         int cur_poc  = h->cur_pic_ptr->poc;

         int *col_poc = sl->ref_list[1][0].parent->field_poc;

         if (col_poc[0] == INT_MAX && col_poc[1] == INT_MAX) {
             av_log(h->avctx, AV_LOG_ERROR, "co located POCs unavailable\n");
             sl->col_parity = 1;
         } else

         sl->col_parity = (FFABS(col_poc[0] - cur_poc) >=
                           FFABS(col_poc[1] - cur_poc));

         ref1sidx =

         sidx     = sl->col_parity;

     // FL -> FL & differ parity

     } else if (!(h->picture_structure & sl->ref_list[1][0].reference) &&

                !sl->ref_list[1][0].parent->mbaff) {

         sl->col_fieldoff = 2 * sl->ref_list[1][0].reference - 3;

     }
 

     if (sl->slice_type_nos != AV_PICTURE_TYPE_B || sl->direct_spatial_mv_pred)

         return;
 

     for (list = 0; list < 2; list++) {

         fill_colmap(h, sl, sl->map_col_to_list0, list, sidx, ref1sidx, 0);

         if (FRAME_MBAFF(h))

             for (field = 0; field < 2; field++)

                 fill_colmap(h, sl, sl->map_col_to_list0_field[field], list, field,

                             field, 1);

     }
 }
 

 static void await_reference_mb_row(const H264Context *const h, H264Ref *ref,

                                    int mb_y)

 {

     int ref_field         = ref->reference - 1;

     int ref_field_picture = ref->parent->field_picture;

     int ref_height        = 16 * h->mb_height >> ref_field_picture;

     if (!HAVE_THREADS || !(h->avctx->active_thread_type & FF_THREAD_FRAME))

         return;
 

     /* FIXME: It can be safe to access mb stuff
      * even if pixels aren't deblocked yet. */

     ff_thread_await_progress(&ref->parent->tf,

                              FFMIN(16 * mb_y >> ref_field_picture,
                                    ref_height - 1),

                              ref_field_picture && ref_field);
 }
 

 static void pred_spatial_direct_motion(const H264Context *const h, H264SliceContext *sl,

                                        int *mb_type)

 {

     int b8_stride = 2;

     int b4_stride = h->b_stride;

     int mb_xy = sl->mb_xy, mb_y = sl->mb_y;

     int mb_type_col[2];
     const int16_t (*l1mv0)[2], (*l1mv1)[2];
     const int8_t *l1ref0, *l1ref1;
     const int is_b8x8 = IS_8X8(*mb_type);

     unsigned int sub_mb_type = MB_TYPE_L0L1;

     int i8, i4;

     int ref[2];
     int mv[2];
     int list;

     assert(sl->ref_list[1][0].reference & 3);

     await_reference_mb_row(h, &sl->ref_list[1][0],

                            sl->mb_y + !!IS_INTERLACED(*mb_type));

 #define MB_TYPE_16x16_OR_INTRA (MB_TYPE_16x16 | MB_TYPE_INTRA4x4 | \
                                 MB_TYPE_INTRA16x16 | MB_TYPE_INTRA_PCM)

 
     /* ref = min(neighbors) */

     for (list = 0; list < 2; list++) {

         int left_ref     = sl->ref_cache[list][scan8[0] - 1];
         int top_ref      = sl->ref_cache[list][scan8[0] - 8];
         int refc         = sl->ref_cache[list][scan8[0] - 8 + 4];
         const int16_t *C = sl->mv_cache[list][scan8[0]  - 8 + 4];

         if (refc == PART_NOT_AVAILABLE) {

             refc = sl->ref_cache[list][scan8[0] - 8 - 1];
             C    = sl->mv_cache[list][scan8[0]  - 8 - 1];

         }

         ref[list] = FFMIN3((unsigned)left_ref,
                            (unsigned)top_ref,
                            (unsigned)refc);
         if (ref[list] >= 0) {
             /* This is just pred_motion() but with the cases removed that
              * cannot happen for direct blocks. */

             const int16_t *const A = sl->mv_cache[list][scan8[0] - 1];
             const int16_t *const B = sl->mv_cache[list][scan8[0] - 8];

 
             int match_count = (left_ref == ref[list]) +
                               (top_ref  == ref[list]) +
                               (refc     == ref[list]);
 
             if (match_count > 1) { // most common
                 mv[list] = pack16to32(mid_pred(A[0], B[0], C[0]),
                                       mid_pred(A[1], B[1], C[1]));
             } else {
                 assert(match_count == 1);
                 if (left_ref == ref[list])
                     mv[list] = AV_RN32A(A);
                 else if (top_ref == ref[list])
                     mv[list] = AV_RN32A(B);
                 else
                     mv[list] = AV_RN32A(C);

             }

             av_assert2(ref[list] < (sl->ref_count[list] << !!FRAME_MBAFF(h)));

         } else {
             int mask = ~(MB_TYPE_L0 << (2 * list));
             mv[list]  = 0;

             ref[list] = -1;

             if (!is_b8x8)

                 *mb_type &= mask;
             sub_mb_type &= mask;
         }
     }

     if (ref[0] < 0 && ref[1] < 0) {

         ref[0] = ref[1] = 0;

         if (!is_b8x8)

             *mb_type |= MB_TYPE_L0L1;
         sub_mb_type |= MB_TYPE_L0L1;
     }
 

     if (!(is_b8x8 | mv[0] | mv[1])) {

         fill_rectangle(&sl->ref_cache[0][scan8[0]], 4, 4, 8, (uint8_t)ref[0], 1);
         fill_rectangle(&sl->ref_cache[1][scan8[0]], 4, 4, 8, (uint8_t)ref[1], 1);
         fill_rectangle(&sl->mv_cache[0][scan8[0]], 4, 4, 8, 0, 4);
         fill_rectangle(&sl->mv_cache[1][scan8[0]], 4, 4, 8, 0, 4);

         *mb_type = (*mb_type & ~(MB_TYPE_8x8 | MB_TYPE_16x8 | MB_TYPE_8x16 |
                                  MB_TYPE_P1L0 | MB_TYPE_P1L1)) |
                    MB_TYPE_16x16 | MB_TYPE_DIRECT2;

         return;
     }
 

     if (IS_INTERLACED(sl->ref_list[1][0].parent->mb_type[mb_xy])) { // AFL/AFR/FR/FL -> AFL/FL

         if (!IS_INTERLACED(*mb_type)) {                    //     AFR/FR    -> AFL/FL

             mb_y  = (sl->mb_y & ~1) + sl->col_parity;
             mb_xy = sl->mb_x +
                     ((sl->mb_y & ~1) + sl->col_parity) * h->mb_stride;

             b8_stride = 0;

         } else {

             mb_y  += sl->col_fieldoff;
             mb_xy += h->mb_stride * sl->col_fieldoff; // non-zero for FL -> FL & differ parity

         }
         goto single_col;

     } else {                                             // AFL/AFR/FR/FL -> AFR/FR
         if (IS_INTERLACED(*mb_type)) {                   // AFL       /FL -> AFR/FR

             mb_y           =  sl->mb_y & ~1;
             mb_xy          = (sl->mb_y & ~1) * h->mb_stride + sl->mb_x;

             mb_type_col[0] = sl->ref_list[1][0].parent->mb_type[mb_xy];
             mb_type_col[1] = sl->ref_list[1][0].parent->mb_type[mb_xy + h->mb_stride];

             b8_stride      = 2 + 4 * h->mb_stride;
             b4_stride     *= 6;
             if (IS_INTERLACED(mb_type_col[0]) !=
                 IS_INTERLACED(mb_type_col[1])) {

                 mb_type_col[0] &= ~MB_TYPE_INTERLACED;
                 mb_type_col[1] &= ~MB_TYPE_INTERLACED;
             }

             sub_mb_type |= MB_TYPE_16x16 | MB_TYPE_DIRECT2; /* B_SUB_8x8 */
             if ((mb_type_col[0] & MB_TYPE_16x16_OR_INTRA) &&
                 (mb_type_col[1] & MB_TYPE_16x16_OR_INTRA) &&
                 !is_b8x8) {
                 *mb_type |= MB_TYPE_16x8 | MB_TYPE_DIRECT2;  /* B_16x8 */
             } else {
                 *mb_type |= MB_TYPE_8x8;

             }

         } else {                                         //     AFR/FR    -> AFR/FR

 single_col:
             mb_type_col[0] =

             mb_type_col[1] = sl->ref_list[1][0].parent->mb_type[mb_xy];

             sub_mb_type |= MB_TYPE_16x16 | MB_TYPE_DIRECT2; /* B_SUB_8x8 */
             if (!is_b8x8 && (mb_type_col[0] & MB_TYPE_16x16_OR_INTRA)) {
                 *mb_type |= MB_TYPE_16x16 | MB_TYPE_DIRECT2; /* B_16x16 */
             } else if (!is_b8x8 &&
                        (mb_type_col[0] & (MB_TYPE_16x8 | MB_TYPE_8x16))) {
                 *mb_type |= MB_TYPE_DIRECT2 |
                             (mb_type_col[0] & (MB_TYPE_16x8 | MB_TYPE_8x16));
             } else {
                 if (!h->sps.direct_8x8_inference_flag) {
                     /* FIXME: Save sub mb types from previous frames (or derive
                      * from MVs) so we know exactly what block size to use. */
                     sub_mb_type += (MB_TYPE_8x8 - MB_TYPE_16x16); /* B_SUB_4x4 */

                 }

                 *mb_type |= MB_TYPE_8x8;

             }
         }
     }
 

     await_reference_mb_row(h, &sl->ref_list[1][0], mb_y);

     l1mv0  = (void*)&sl->ref_list[1][0].parent->motion_val[0][h->mb2b_xy[mb_xy]];
     l1mv1  = (void*)&sl->ref_list[1][0].parent->motion_val[1][h->mb2b_xy[mb_xy]];

     l1ref0 = &sl->ref_list[1][0].parent->ref_index[0][4 * mb_xy];
     l1ref1 = &sl->ref_list[1][0].parent->ref_index[1][4 * mb_xy];

     if (!b8_stride) {

         if (sl->mb_y & 1) {

             l1ref0 += 2;
             l1ref1 += 2;

             l1mv0  += 2 * b4_stride;
             l1mv1  += 2 * b4_stride;

         }
     }
 

     if (IS_INTERLACED(*mb_type) != IS_INTERLACED(mb_type_col[0])) {
         int n = 0;
         for (i8 = 0; i8 < 4; i8++) {
             int x8  = i8 & 1;
             int y8  = i8 >> 1;
             int xy8 = x8     + y8 * b8_stride;
             int xy4 = x8 * 3 + y8 * b4_stride;
             int a, b;
 

             if (is_b8x8 && !IS_DIRECT(sl->sub_mb_type[i8]))

                 continue;

             sl->sub_mb_type[i8] = sub_mb_type;

             fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8,

                            (uint8_t)ref[0], 1);

             fill_rectangle(&sl->ref_cache[1][scan8[i8 * 4]], 2, 2, 8,

                            (uint8_t)ref[1], 1);

             if (!IS_INTRA(mb_type_col[y8]) && !sl->ref_list[1][0].parent->long_ref &&

                 ((l1ref0[xy8] == 0 &&
                   FFABS(l1mv0[xy4][0]) <= 1 &&
                   FFABS(l1mv0[xy4][1]) <= 1) ||
                  (l1ref0[xy8] < 0 &&
                   l1ref1[xy8] == 0 &&
                   FFABS(l1mv1[xy4][0]) <= 1 &&
                   FFABS(l1mv1[xy4][1]) <= 1))) {
                 a =
                 b = 0;
                 if (ref[0] > 0)
                     a = mv[0];
                 if (ref[1] > 0)
                     b = mv[1];
                 n++;
             } else {
                 a = mv[0];
                 b = mv[1];

             }

             fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8, a, 4);
             fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8, b, 4);

         }
         if (!is_b8x8 && !(n & 3))
             *mb_type = (*mb_type & ~(MB_TYPE_8x8 | MB_TYPE_16x8 | MB_TYPE_8x16 |
                                      MB_TYPE_P1L0 | MB_TYPE_P1L1)) |
                        MB_TYPE_16x16 | MB_TYPE_DIRECT2;
     } else if (IS_16X16(*mb_type)) {
         int a, b;

         fill_rectangle(&sl->ref_cache[0][scan8[0]], 4, 4, 8, (uint8_t)ref[0], 1);
         fill_rectangle(&sl->ref_cache[1][scan8[0]], 4, 4, 8, (uint8_t)ref[1], 1);

         if (!IS_INTRA(mb_type_col[0]) && !sl->ref_list[1][0].parent->long_ref &&

             ((l1ref0[0] == 0 &&
               FFABS(l1mv0[0][0]) <= 1 &&
               FFABS(l1mv0[0][1]) <= 1) ||
              (l1ref0[0] < 0 && !l1ref1[0] &&
               FFABS(l1mv1[0][0]) <= 1 &&
               FFABS(l1mv1[0][1]) <= 1 &&
               h->x264_build > 33U))) {
             a = b = 0;
             if (ref[0] > 0)
                 a = mv[0];
             if (ref[1] > 0)
                 b = mv[1];
         } else {
             a = mv[0];
             b = mv[1];
         }

         fill_rectangle(&sl->mv_cache[0][scan8[0]], 4, 4, 8, a, 4);
         fill_rectangle(&sl->mv_cache[1][scan8[0]], 4, 4, 8, b, 4);

     } else {
         int n = 0;
         for (i8 = 0; i8 < 4; i8++) {
             const int x8 = i8 & 1;
             const int y8 = i8 >> 1;
 

             if (is_b8x8 && !IS_DIRECT(sl->sub_mb_type[i8]))

                 continue;

             sl->sub_mb_type[i8] = sub_mb_type;

             fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8, mv[0], 4);
             fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8, mv[1], 4);
             fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8,

                            (uint8_t)ref[0], 1);

             fill_rectangle(&sl->ref_cache[1][scan8[i8 * 4]], 2, 2, 8,

                            (uint8_t)ref[1], 1);
 
             assert(b8_stride == 2);
             /* col_zero_flag */

             if (!IS_INTRA(mb_type_col[0]) && !sl->ref_list[1][0].parent->long_ref &&

                 (l1ref0[i8] == 0 ||
                  (l1ref0[i8] < 0 &&
                   l1ref1[i8] == 0 &&
                   h->x264_build > 33U))) {
                 const int16_t (*l1mv)[2] = l1ref0[i8] == 0 ? l1mv0 : l1mv1;
                 if (IS_SUB_8X8(sub_mb_type)) {
                     const int16_t *mv_col = l1mv[x8 * 3 + y8 * 3 * b4_stride];
                     if (FFABS(mv_col[0]) <= 1 && FFABS(mv_col[1]) <= 1) {
                         if (ref[0] == 0)

                             fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2,

                                            8, 0, 4);
                         if (ref[1] == 0)

                             fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2,

                                            8, 0, 4);
                         n += 4;
                     }
                 } else {
                     int m = 0;
                     for (i4 = 0; i4 < 4; i4++) {
                         const int16_t *mv_col = l1mv[x8 * 2 + (i4 & 1) +
                                                      (y8 * 2 + (i4 >> 1)) * b4_stride];
                         if (FFABS(mv_col[0]) <= 1 && FFABS(mv_col[1]) <= 1) {
                             if (ref[0] == 0)

                                 AV_ZERO32(sl->mv_cache[0][scan8[i8 * 4 + i4]]);

                             if (ref[1] == 0)

                                 AV_ZERO32(sl->mv_cache[1][scan8[i8 * 4 + i4]]);

                             m++;

                         }
                     }

                     if (!(m & 3))

                         sl->sub_mb_type[i8] += MB_TYPE_16x16 - MB_TYPE_8x8;

                     n += m;

                 }
             }
         }

         if (!is_b8x8 && !(n & 15))
             *mb_type = (*mb_type & ~(MB_TYPE_8x8 | MB_TYPE_16x8 | MB_TYPE_8x16 |
                                      MB_TYPE_P1L0 | MB_TYPE_P1L1)) |
                        MB_TYPE_16x16 | MB_TYPE_DIRECT2;
     }

 }
 

 static void pred_temp_direct_motion(const H264Context *const h, H264SliceContext *sl,

                                     int *mb_type)

 {

     int b8_stride = 2;

     int b4_stride = h->b_stride;

     int mb_xy = sl->mb_xy, mb_y = sl->mb_y;

     int mb_type_col[2];
     const int16_t (*l1mv0)[2], (*l1mv1)[2];
     const int8_t *l1ref0, *l1ref1;
     const int is_b8x8 = IS_8X8(*mb_type);
     unsigned int sub_mb_type;
     int i8, i4;
 

     assert(sl->ref_list[1][0].reference & 3);

     await_reference_mb_row(h, &sl->ref_list[1][0],

                            sl->mb_y + !!IS_INTERLACED(*mb_type));

     if (IS_INTERLACED(sl->ref_list[1][0].parent->mb_type[mb_xy])) { // AFL/AFR/FR/FL -> AFL/FL

         if (!IS_INTERLACED(*mb_type)) {                    //     AFR/FR    -> AFL/FL

             mb_y  = (sl->mb_y & ~1) + sl->col_parity;
             mb_xy = sl->mb_x +
                     ((sl->mb_y & ~1) + sl->col_parity) * h->mb_stride;

             b8_stride = 0;

         } else {

             mb_y  += sl->col_fieldoff;
             mb_xy += h->mb_stride * sl->col_fieldoff; // non-zero for FL -> FL & differ parity

         }
         goto single_col;

     } else {                                        // AFL/AFR/FR/FL -> AFR/FR
         if (IS_INTERLACED(*mb_type)) {              // AFL       /FL -> AFR/FR

             mb_y           = sl->mb_y & ~1;
             mb_xy          = sl->mb_x + (sl->mb_y & ~1) * h->mb_stride;

             mb_type_col[0] = sl->ref_list[1][0].parent->mb_type[mb_xy];
             mb_type_col[1] = sl->ref_list[1][0].parent->mb_type[mb_xy + h->mb_stride];

             b8_stride      = 2 + 4 * h->mb_stride;
             b4_stride     *= 6;
             if (IS_INTERLACED(mb_type_col[0]) !=
                 IS_INTERLACED(mb_type_col[1])) {

                 mb_type_col[0] &= ~MB_TYPE_INTERLACED;
                 mb_type_col[1] &= ~MB_TYPE_INTERLACED;
             }

             sub_mb_type = MB_TYPE_16x16 | MB_TYPE_P0L0 | MB_TYPE_P0L1 |
                           MB_TYPE_DIRECT2;                  /* B_SUB_8x8 */

             if ((mb_type_col[0] & MB_TYPE_16x16_OR_INTRA) &&
                 (mb_type_col[1] & MB_TYPE_16x16_OR_INTRA) &&
                 !is_b8x8) {
                 *mb_type |= MB_TYPE_16x8 | MB_TYPE_L0L1 |
                             MB_TYPE_DIRECT2;                /* B_16x8 */
             } else {
                 *mb_type |= MB_TYPE_8x8 | MB_TYPE_L0L1;

             }

         } else {                                    //     AFR/FR    -> AFR/FR

 single_col:

             mb_type_col[0]     =

                 mb_type_col[1] = sl->ref_list[1][0].parent->mb_type[mb_xy];

 
             sub_mb_type = MB_TYPE_16x16 | MB_TYPE_P0L0 | MB_TYPE_P0L1 |
                           MB_TYPE_DIRECT2;                  /* B_SUB_8x8 */
             if (!is_b8x8 && (mb_type_col[0] & MB_TYPE_16x16_OR_INTRA)) {
                 *mb_type |= MB_TYPE_16x16 | MB_TYPE_P0L0 | MB_TYPE_P0L1 |
                             MB_TYPE_DIRECT2;                /* B_16x16 */
             } else if (!is_b8x8 &&
                        (mb_type_col[0] & (MB_TYPE_16x8 | MB_TYPE_8x16))) {
                 *mb_type |= MB_TYPE_L0L1 | MB_TYPE_DIRECT2 |
                             (mb_type_col[0] & (MB_TYPE_16x8 | MB_TYPE_8x16));
             } else {
                 if (!h->sps.direct_8x8_inference_flag) {
                     /* FIXME: save sub mb types from previous frames (or derive
                      * from MVs) so we know exactly what block size to use */
                     sub_mb_type = MB_TYPE_8x8 | MB_TYPE_P0L0 | MB_TYPE_P0L1 |
                                   MB_TYPE_DIRECT2;          /* B_SUB_4x4 */

                 }

                 *mb_type |= MB_TYPE_8x8 | MB_TYPE_L0L1;

             }
         }
     }
 

     await_reference_mb_row(h, &sl->ref_list[1][0], mb_y);

     l1mv0  = (void*)&sl->ref_list[1][0].parent->motion_val[0][h->mb2b_xy[mb_xy]];
     l1mv1  = (void*)&sl->ref_list[1][0].parent->motion_val[1][h->mb2b_xy[mb_xy]];

     l1ref0 = &sl->ref_list[1][0].parent->ref_index[0][4 * mb_xy];
     l1ref1 = &sl->ref_list[1][0].parent->ref_index[1][4 * mb_xy];

     if (!b8_stride) {

         if (sl->mb_y & 1) {

             l1ref0 += 2;
             l1ref1 += 2;

             l1mv0  += 2 * b4_stride;
             l1mv1  += 2 * b4_stride;

         }
     }
 
     {

         const int *map_col_to_list0[2] = { sl->map_col_to_list0[0],
                                            sl->map_col_to_list0[1] };

         const int *dist_scale_factor = sl->dist_scale_factor;

         int ref_offset;

         if (FRAME_MBAFF(h) && IS_INTERLACED(*mb_type)) {

             map_col_to_list0[0] = sl->map_col_to_list0_field[sl->mb_y & 1][0];
             map_col_to_list0[1] = sl->map_col_to_list0_field[sl->mb_y & 1][1];
             dist_scale_factor   = sl->dist_scale_factor_field[sl->mb_y & 1];

         }

         ref_offset = (sl->ref_list[1][0].parent->mbaff << 4) & (mb_type_col[0] >> 3);

         if (IS_INTERLACED(*mb_type) != IS_INTERLACED(mb_type_col[0])) {
             int y_shift = 2 * !IS_INTERLACED(*mb_type);

             assert(h->sps.direct_8x8_inference_flag);

             for (i8 = 0; i8 < 4; i8++) {
                 const int x8 = i8 & 1;
                 const int y8 = i8 >> 1;

                 int ref0, scale;

                 const int16_t (*l1mv)[2] = l1mv0;

                 if (is_b8x8 && !IS_DIRECT(sl->sub_mb_type[i8]))

                     continue;

                 sl->sub_mb_type[i8] = sub_mb_type;

                 fill_rectangle(&sl->ref_cache[1][scan8[i8 * 4]], 2, 2, 8, 0, 1);

                 if (IS_INTRA(mb_type_col[y8])) {

                     fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8, 0, 1);
                     fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8, 0, 4);
                     fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8, 0, 4);

                     continue;
                 }
 

                 ref0 = l1ref0[x8 + y8 * b8_stride];
                 if (ref0 >= 0)

                     ref0 = map_col_to_list0[0][ref0 + ref_offset];

                 else {
                     ref0 = map_col_to_list0[1][l1ref1[x8 + y8 * b8_stride] +
                                                ref_offset];
                     l1mv = l1mv1;

                 }
                 scale = dist_scale_factor[ref0];

                 fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8,

                                ref0, 1);

 
                 {

                     const int16_t *mv_col = l1mv[x8 * 3 + y8 * b4_stride];
                     int my_col            = (mv_col[1] << y_shift) / 2;
                     int mx                = (scale * mv_col[0] + 128) >> 8;
                     int my                = (scale * my_col    + 128) >> 8;

                     fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8,

                                    pack16to32(mx, my), 4);

                     fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8,

                                    pack16to32(mx - mv_col[0], my - my_col), 4);

                 }
             }
             return;
         }
 
         /* one-to-one mv scaling */
 

         if (IS_16X16(*mb_type)) {

             int ref, mv0, mv1;
 

             fill_rectangle(&sl->ref_cache[1][scan8[0]], 4, 4, 8, 0, 1);

             if (IS_INTRA(mb_type_col[0])) {
                 ref = mv0 = mv1 = 0;
             } else {

                 const int ref0 = l1ref0[0] >= 0 ? map_col_to_list0[0][l1ref0[0] + ref_offset]
                                                 : map_col_to_list0[1][l1ref1[0] + ref_offset];
                 const int scale = dist_scale_factor[ref0];
                 const int16_t *mv_col = l1ref0[0] >= 0 ? l1mv0[0] : l1mv1[0];
                 int mv_l0[2];
                 mv_l0[0] = (scale * mv_col[0] + 128) >> 8;
                 mv_l0[1] = (scale * mv_col[1] + 128) >> 8;

                 ref      = ref0;
                 mv0      = pack16to32(mv_l0[0], mv_l0[1]);
                 mv1      = pack16to32(mv_l0[0] - mv_col[0], mv_l0[1] - mv_col[1]);

             }

             fill_rectangle(&sl->ref_cache[0][scan8[0]], 4, 4, 8, ref, 1);
             fill_rectangle(&sl->mv_cache[0][scan8[0]], 4, 4, 8, mv0, 4);
             fill_rectangle(&sl->mv_cache[1][scan8[0]], 4, 4, 8, mv1, 4);

         } else {
             for (i8 = 0; i8 < 4; i8++) {
                 const int x8 = i8 & 1;
                 const int y8 = i8 >> 1;

                 int ref0, scale;

                 const int16_t (*l1mv)[2] = l1mv0;

                 if (is_b8x8 && !IS_DIRECT(sl->sub_mb_type[i8]))

                     continue;

                 sl->sub_mb_type[i8] = sub_mb_type;

                 fill_rectangle(&sl->ref_cache[1][scan8[i8 * 4]], 2, 2, 8, 0, 1);

                 if (IS_INTRA(mb_type_col[0])) {

                     fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8, 0, 1);
                     fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8, 0, 4);
                     fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8, 0, 4);

                     continue;
                 }
 

                 assert(b8_stride == 2);
                 ref0 = l1ref0[i8];

                 if (ref0 >= 0)

                     ref0 = map_col_to_list0[0][ref0 + ref_offset];

                 else {

                     ref0 = map_col_to_list0[1][l1ref1[i8] + ref_offset];

                     l1mv = l1mv1;

                 }
                 scale = dist_scale_factor[ref0];
 

                 fill_rectangle(&sl->ref_cache[0][scan8[i8 * 4]], 2, 2, 8,

                                ref0, 1);
                 if (IS_SUB_8X8(sub_mb_type)) {
                     const int16_t *mv_col = l1mv[x8 * 3 + y8 * 3 * b4_stride];
                     int mx                = (scale * mv_col[0] + 128) >> 8;
                     int my                = (scale * mv_col[1] + 128) >> 8;

                     fill_rectangle(&sl->mv_cache[0][scan8[i8 * 4]], 2, 2, 8,

                                    pack16to32(mx, my), 4);

                     fill_rectangle(&sl->mv_cache[1][scan8[i8 * 4]], 2, 2, 8,

                                    pack16to32(mx - mv_col[0], my - mv_col[1]), 4);
                 } else {
                     for (i4 = 0; i4 < 4; i4++) {
                         const int16_t *mv_col = l1mv[x8 * 2 + (i4 & 1) +
                                                      (y8 * 2 + (i4 >> 1)) * b4_stride];

                         int16_t *mv_l0 = sl->mv_cache[0][scan8[i8 * 4 + i4]];

                         mv_l0[0] = (scale * mv_col[0] + 128) >> 8;
                         mv_l0[1] = (scale * mv_col[1] + 128) >> 8;

                         AV_WN32A(sl->mv_cache[1][scan8[i8 * 4 + i4]],

                                  pack16to32(mv_l0[0] - mv_col[0],
                                             mv_l0[1] - mv_col[1]));
                     }

                 }
             }
         }
     }
 }

 void ff_h264_pred_direct_motion(const H264Context *const h, H264SliceContext *sl,

                                 int *mb_type)

 {

     if (sl->direct_spatial_mv_pred)

         pred_spatial_direct_motion(h, sl, mb_type);

     else

         pred_temp_direct_motion(h, sl, mb_type);

 }