/*
  * VC-1 and WMV3 decoder
  * Copyright (c) 2011 Mashiat Sarker Shakkhar
  * Copyright (c) 2006-2007 Konstantin Shishkov
  * Partly based on vc9.c (c) 2005 Anonymous, Alex Beregszaszi, Michael Niedermayer
  *

  * This file is part of FFmpeg.

  *

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

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

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

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

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

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * VC-1 and WMV3 block decoding routines
  */
 
 #include "avcodec.h"
 #include "h264chroma.h"
 #include "mathops.h"
 #include "mpegvideo.h"
 #include "vc1.h"
 

 static av_always_inline void vc1_scale_luma(uint8_t *srcY,
                                             int k, int linesize)
 {
     int i, j;
     for (j = 0; j < k; j++) {
         for (i = 0; i < k; i++)
             srcY[i] = ((srcY[i] - 128) >> 1) + 128;
         srcY += linesize;
     }
 }
 
 static av_always_inline void vc1_scale_chroma(uint8_t *srcU, uint8_t *srcV,
                                               int k, int uvlinesize)
 {
     int i, j;
     for (j = 0; j < k; j++) {
         for (i = 0; i < k; i++) {
             srcU[i] = ((srcU[i] - 128) >> 1) + 128;
             srcV[i] = ((srcV[i] - 128) >> 1) + 128;
         }
         srcU += uvlinesize;
         srcV += uvlinesize;
     }
 }
 
 static av_always_inline void vc1_lut_scale_luma(uint8_t *srcY,
                                                 uint8_t *lut1, uint8_t *lut2,
                                                 int k, int linesize)
 {
     int i, j;
 
     for (j = 0; j < k; j += 2) {
         for (i = 0; i < k; i++)
             srcY[i] = lut1[srcY[i]];
         srcY += linesize;
 
         if (j + 1 == k)
             break;
 
         for (i = 0; i < k; i++)
             srcY[i] = lut2[srcY[i]];
         srcY += linesize;
     }
 }
 
 static av_always_inline void vc1_lut_scale_chroma(uint8_t *srcU, uint8_t *srcV,
                                                   uint8_t *lut1, uint8_t *lut2,
                                                   int k, int uvlinesize)
 {
     int i, j;
 
     for (j = 0; j < k; j += 2) {
         for (i = 0; i < k; i++) {
             srcU[i] = lut1[srcU[i]];
             srcV[i] = lut1[srcV[i]];
         }
         srcU += uvlinesize;
         srcV += uvlinesize;
 
         if (j + 1 == k)
             break;
 
         for (i = 0; i < k; i++) {
             srcU[i] = lut2[srcU[i]];
             srcV[i] = lut2[srcV[i]];
         }
         srcU += uvlinesize;
         srcV += uvlinesize;
     }
 }
 

 static const uint8_t popcount4[16] = { 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4 };
 
 static av_always_inline int get_luma_mv(VC1Context *v, int dir, int16_t *tx, int16_t *ty)
 {
     MpegEncContext *s = &v->s;
     int idx = v->mv_f[dir][s->block_index[0] + v->blocks_off] |
              (v->mv_f[dir][s->block_index[1] + v->blocks_off] << 1) |
              (v->mv_f[dir][s->block_index[2] + v->blocks_off] << 2) |
              (v->mv_f[dir][s->block_index[3] + v->blocks_off] << 3);
     static const uint8_t index2[16] = { 0, 0, 0, 0x23, 0, 0x13, 0x03, 0, 0, 0x12, 0x02, 0, 0x01, 0, 0, 0 };
     int opp_count = popcount4[idx];
 
     switch (opp_count) {
     case 0:
     case 4:
         *tx = median4(s->mv[dir][0][0], s->mv[dir][1][0], s->mv[dir][2][0], s->mv[dir][3][0]);
         *ty = median4(s->mv[dir][0][1], s->mv[dir][1][1], s->mv[dir][2][1], s->mv[dir][3][1]);
         break;
     case 1:
         *tx = mid_pred(s->mv[dir][idx < 2][0], s->mv[dir][1 + (idx < 4)][0], s->mv[dir][2 + (idx < 8)][0]);
         *ty = mid_pred(s->mv[dir][idx < 2][1], s->mv[dir][1 + (idx < 4)][1], s->mv[dir][2 + (idx < 8)][1]);
         break;
     case 3:
         *tx = mid_pred(s->mv[dir][idx > 0xd][0], s->mv[dir][1 + (idx > 0xb)][0], s->mv[dir][2 + (idx > 0x7)][0]);
         *ty = mid_pred(s->mv[dir][idx > 0xd][1], s->mv[dir][1 + (idx > 0xb)][1], s->mv[dir][2 + (idx > 0x7)][1]);
         break;
     case 2:
         *tx = (s->mv[dir][index2[idx] >> 4][0] + s->mv[dir][index2[idx] & 0xf][0]) / 2;
         *ty = (s->mv[dir][index2[idx] >> 4][1] + s->mv[dir][index2[idx] & 0xf][1]) / 2;
         break;
     }
     return opp_count;
 }
 
 static av_always_inline int get_chroma_mv(VC1Context *v, int dir, int16_t *tx, int16_t *ty)
 {
     MpegEncContext *s = &v->s;
     int idx = !v->mb_type[0][s->block_index[0]] |
              (!v->mb_type[0][s->block_index[1]] << 1) |
              (!v->mb_type[0][s->block_index[2]] << 2) |
              (!v->mb_type[0][s->block_index[3]] << 3);
     static const uint8_t index2[16] = { 0, 0, 0, 0x01, 0, 0x02, 0x12, 0, 0, 0x03, 0x13, 0, 0x23, 0, 0, 0 };
     int valid_count = popcount4[idx];
 
     switch (valid_count) {
     case 4:
         *tx = median4(s->mv[dir][0][0], s->mv[dir][1][0], s->mv[dir][2][0], s->mv[dir][3][0]);
         *ty = median4(s->mv[dir][0][1], s->mv[dir][1][1], s->mv[dir][2][1], s->mv[dir][3][1]);
         break;
     case 3:
         *tx = mid_pred(s->mv[dir][idx > 0xd][0], s->mv[dir][1 + (idx > 0xb)][0], s->mv[dir][2 + (idx > 0x7)][0]);
         *ty = mid_pred(s->mv[dir][idx > 0xd][1], s->mv[dir][1 + (idx > 0xb)][1], s->mv[dir][2 + (idx > 0x7)][1]);
         break;
     case 2:
         *tx = (s->mv[dir][index2[idx] >> 4][0] + s->mv[dir][index2[idx] & 0xf][0]) / 2;
         *ty = (s->mv[dir][index2[idx] >> 4][1] + s->mv[dir][index2[idx] & 0xf][1]) / 2;
         break;
     default:
         return 0;
     }
     return valid_count;
 }
 

 /** Do motion compensation over 1 macroblock
  * Mostly adapted hpel_motion and qpel_motion from mpegvideo.c
  */
 void ff_vc1_mc_1mv(VC1Context *v, int dir)
 {
     MpegEncContext *s = &v->s;
     H264ChromaContext *h264chroma = &v->h264chroma;
     uint8_t *srcY, *srcU, *srcV;
     int dxy, mx, my, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y;
     int v_edge_pos = s->v_edge_pos >> v->field_mode;
     int i;
     uint8_t (*luty)[256], (*lutuv)[256];
     int use_ic;
 
     if ((!v->field_mode ||
          (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) &&
         !v->s.last_picture.f->data[0])
         return;
 
     mx = s->mv[dir][0][0];
     my = s->mv[dir][0][1];
 
     // store motion vectors for further use in B frames
     if (s->pict_type == AV_PICTURE_TYPE_P) {
         for (i = 0; i < 4; i++) {
             s->current_picture.motion_val[1][s->block_index[i] + v->blocks_off][0] = mx;
             s->current_picture.motion_val[1][s->block_index[i] + v->blocks_off][1] = my;
         }
     }
 
     uvmx = (mx + ((mx & 3) == 3)) >> 1;
     uvmy = (my + ((my & 3) == 3)) >> 1;
     v->luma_mv[s->mb_x][0] = uvmx;
     v->luma_mv[s->mb_x][1] = uvmy;
 
     if (v->field_mode &&
         v->cur_field_type != v->ref_field_type[dir]) {
         my   = my   - 2 + 4 * v->cur_field_type;
         uvmy = uvmy - 2 + 4 * v->cur_field_type;
     }
 
     // fastuvmc shall be ignored for interlaced frame picture
     if (v->fastuvmc && (v->fcm != ILACE_FRAME)) {
         uvmx = uvmx + ((uvmx < 0) ? (uvmx & 1) : -(uvmx & 1));
         uvmy = uvmy + ((uvmy < 0) ? (uvmy & 1) : -(uvmy & 1));
     }
     if (!dir) {
         if (v->field_mode && (v->cur_field_type != v->ref_field_type[dir]) && v->second_field) {
             srcY = s->current_picture.f->data[0];
             srcU = s->current_picture.f->data[1];
             srcV = s->current_picture.f->data[2];
             luty  = v->curr_luty;
             lutuv = v->curr_lutuv;

             use_ic = *v->curr_use_ic;

         } else {
             srcY = s->last_picture.f->data[0];
             srcU = s->last_picture.f->data[1];
             srcV = s->last_picture.f->data[2];
             luty  = v->last_luty;
             lutuv = v->last_lutuv;
             use_ic = v->last_use_ic;
         }
     } else {
         srcY = s->next_picture.f->data[0];
         srcU = s->next_picture.f->data[1];
         srcV = s->next_picture.f->data[2];
         luty  = v->next_luty;
         lutuv = v->next_lutuv;
         use_ic = v->next_use_ic;
     }
 
     if (!srcY || !srcU) {
         av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
         return;
     }
 
     src_x   = s->mb_x * 16 + (mx   >> 2);
     src_y   = s->mb_y * 16 + (my   >> 2);
     uvsrc_x = s->mb_x *  8 + (uvmx >> 2);
     uvsrc_y = s->mb_y *  8 + (uvmy >> 2);
 
     if (v->profile != PROFILE_ADVANCED) {
         src_x   = av_clip(  src_x, -16, s->mb_width  * 16);
         src_y   = av_clip(  src_y, -16, s->mb_height * 16);
         uvsrc_x = av_clip(uvsrc_x,  -8, s->mb_width  *  8);
         uvsrc_y = av_clip(uvsrc_y,  -8, s->mb_height *  8);
     } else {
         src_x   = av_clip(  src_x, -17, s->avctx->coded_width);
         src_y   = av_clip(  src_y, -18, s->avctx->coded_height + 1);
         uvsrc_x = av_clip(uvsrc_x,  -8, s->avctx->coded_width  >> 1);
         uvsrc_y = av_clip(uvsrc_y,  -8, s->avctx->coded_height >> 1);
     }
 
     srcY += src_y   * s->linesize   + src_x;
     srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
     srcV += uvsrc_y * s->uvlinesize + uvsrc_x;
 
     if (v->field_mode && v->ref_field_type[dir]) {
         srcY += s->current_picture_ptr->f->linesize[0];
         srcU += s->current_picture_ptr->f->linesize[1];
         srcV += s->current_picture_ptr->f->linesize[2];
     }
 
     /* for grayscale we should not try to read from unknown area */

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY) {

         srcU = s->sc.edge_emu_buffer + 18 * s->linesize;
         srcV = s->sc.edge_emu_buffer + 18 * s->linesize;

     }
 
     if (v->rangeredfrm || use_ic
         || s->h_edge_pos < 22 || v_edge_pos < 22
         || (unsigned)(src_x - s->mspel) > s->h_edge_pos - (mx&3) - 16 - s->mspel * 3
         || (unsigned)(src_y - 1)        > v_edge_pos    - (my&3) - 16 - 3) {

         uint8_t *ubuf = s->sc.edge_emu_buffer + 19 * s->linesize;

         uint8_t *vbuf = ubuf + 9 * s->uvlinesize;

         const int k = 17 + s->mspel * 2;

 
         srcY -= s->mspel * (1 + s->linesize);

         s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, srcY,

                                  s->linesize, s->linesize,

                                  k, k,

                                  src_x - s->mspel, src_y - s->mspel,
                                  s->h_edge_pos, v_edge_pos);

         srcY = s->sc.edge_emu_buffer;

         s->vdsp.emulated_edge_mc(ubuf, srcU,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1,

                                  uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);
         s->vdsp.emulated_edge_mc(vbuf, srcV,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1,

                                  uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);
         srcU = ubuf;
         srcV = vbuf;

         /* if we deal with range reduction we need to scale source blocks */
         if (v->rangeredfrm) {

             vc1_scale_luma(srcY, k, s->linesize);
             vc1_scale_chroma(srcU, srcV, 9, s->uvlinesize);

         }
         /* if we deal with intensity compensation we need to scale source blocks */
         if (use_ic) {

             vc1_lut_scale_luma(srcY,
                                luty[v->field_mode ? v->ref_field_type[dir] : ((0 + src_y - s->mspel) & 1)],
                                luty[v->field_mode ? v->ref_field_type[dir] : ((1 + src_y - s->mspel) & 1)],
                                k, s->linesize);
             vc1_lut_scale_chroma(srcU, srcV,
                                  lutuv[v->field_mode ? v->ref_field_type[dir] : ((0 + uvsrc_y) & 1)],
                                  lutuv[v->field_mode ? v->ref_field_type[dir] : ((1 + uvsrc_y) & 1)],
                                  9, s->uvlinesize);

         }
         srcY += s->mspel * (1 + s->linesize);
     }
 
     if (s->mspel) {
         dxy = ((my & 3) << 2) | (mx & 3);

         v->vc1dsp.put_vc1_mspel_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, v->rnd);

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

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY)

         return;

     /* Chroma MC always uses qpel bilinear */
     uvmx = (uvmx & 3) << 1;
     uvmy = (uvmy & 3) << 1;
     if (!v->rnd) {
         h264chroma->put_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         h264chroma->put_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
     } else {
         v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
     }
 }
 
 /** Do motion compensation for 4-MV macroblock - luminance block
  */
 void ff_vc1_mc_4mv_luma(VC1Context *v, int n, int dir, int avg)
 {
     MpegEncContext *s = &v->s;
     uint8_t *srcY;
     int dxy, mx, my, src_x, src_y;
     int off;
     int fieldmv = (v->fcm == ILACE_FRAME) ? v->blk_mv_type[s->block_index[n]] : 0;
     int v_edge_pos = s->v_edge_pos >> v->field_mode;
     uint8_t (*luty)[256];
     int use_ic;
 
     if ((!v->field_mode ||
          (v->ref_field_type[dir] == 1 && v->cur_field_type == 1)) &&
         !v->s.last_picture.f->data[0])
         return;
 
     mx = s->mv[dir][n][0];
     my = s->mv[dir][n][1];
 
     if (!dir) {
         if (v->field_mode && (v->cur_field_type != v->ref_field_type[dir]) && v->second_field) {
             srcY = s->current_picture.f->data[0];
             luty = v->curr_luty;

             use_ic = *v->curr_use_ic;

         } else {
             srcY = s->last_picture.f->data[0];
             luty = v->last_luty;
             use_ic = v->last_use_ic;
         }
     } else {
         srcY = s->next_picture.f->data[0];
         luty = v->next_luty;
         use_ic = v->next_use_ic;
     }
 
     if (!srcY) {
         av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
         return;
     }
 
     if (v->field_mode) {
         if (v->cur_field_type != v->ref_field_type[dir])
             my = my - 2 + 4 * v->cur_field_type;
     }
 
     if (s->pict_type == AV_PICTURE_TYPE_P && n == 3 && v->field_mode) {

         int opp_count = get_luma_mv(v, 0,
                                     &s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0],
                                     &s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1]);
         int k, f = opp_count > 2;

         for (k = 0; k < 4; k++)
             v->mv_f[1][s->block_index[k] + v->blocks_off] = f;
     }
 
     if (v->fcm == ILACE_FRAME) {  // not sure if needed for other types of picture
         int qx, qy;
         int width  = s->avctx->coded_width;
         int height = s->avctx->coded_height >> 1;
         if (s->pict_type == AV_PICTURE_TYPE_P) {
             s->current_picture.motion_val[1][s->block_index[n] + v->blocks_off][0] = mx;
             s->current_picture.motion_val[1][s->block_index[n] + v->blocks_off][1] = my;
         }
         qx = (s->mb_x * 16) + (mx >> 2);
         qy = (s->mb_y *  8) + (my >> 3);
 
         if (qx < -17)
             mx -= 4 * (qx + 17);
         else if (qx > width)
             mx -= 4 * (qx - width);
         if (qy < -18)
             my -= 8 * (qy + 18);
         else if (qy > height + 1)
             my -= 8 * (qy - height - 1);
     }
 
     if ((v->fcm == ILACE_FRAME) && fieldmv)
         off = ((n > 1) ? s->linesize : 0) + (n & 1) * 8;
     else
         off = s->linesize * 4 * (n & 2) + (n & 1) * 8;
 
     src_x = s->mb_x * 16 + (n & 1) * 8 + (mx >> 2);
     if (!fieldmv)
         src_y = s->mb_y * 16 + (n & 2) * 4 + (my >> 2);
     else
         src_y = s->mb_y * 16 + ((n > 1) ? 1 : 0) + (my >> 2);
 
     if (v->profile != PROFILE_ADVANCED) {
         src_x = av_clip(src_x, -16, s->mb_width  * 16);
         src_y = av_clip(src_y, -16, s->mb_height * 16);
     } else {
         src_x = av_clip(src_x, -17, s->avctx->coded_width);
         if (v->fcm == ILACE_FRAME) {
             if (src_y & 1)
                 src_y = av_clip(src_y, -17, s->avctx->coded_height + 1);
             else
                 src_y = av_clip(src_y, -18, s->avctx->coded_height);
         } else {
             src_y = av_clip(src_y, -18, s->avctx->coded_height + 1);
         }
     }
 
     srcY += src_y * s->linesize + src_x;
     if (v->field_mode && v->ref_field_type[dir])
         srcY += s->current_picture_ptr->f->linesize[0];
 

     if (fieldmv) {
         if (!(src_y & 1))
             v_edge_pos--;
         else
             src_y -= (src_y < 4);
     }

     if (v->rangeredfrm || use_ic
         || s->h_edge_pos < 13 || v_edge_pos < 23
         || (unsigned)(src_x - s->mspel) > s->h_edge_pos - (mx & 3) - 8 - s->mspel * 2
         || (unsigned)(src_y - (s->mspel << fieldmv)) > v_edge_pos - (my & 3) - ((8 + s->mspel * 2) << fieldmv)) {

         const int k = 9 + s->mspel * 2;
 

         srcY -= s->mspel * (1 + (s->linesize << fieldmv));
         /* check emulate edge stride and offset */

         s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, srcY,

                                  s->linesize, s->linesize,

                                  k, k << fieldmv,

                                  src_x - s->mspel, src_y - (s->mspel << fieldmv),
                                  s->h_edge_pos, v_edge_pos);

         srcY = s->sc.edge_emu_buffer;

         /* if we deal with range reduction we need to scale source blocks */
         if (v->rangeredfrm) {

             vc1_scale_luma(srcY, k, s->linesize << fieldmv);

         }
         /* if we deal with intensity compensation we need to scale source blocks */
         if (use_ic) {

             vc1_lut_scale_luma(srcY,
                                luty[v->field_mode ? v->ref_field_type[dir] : (((0<<fieldmv)+src_y - (s->mspel << fieldmv)) & 1)],
                                luty[v->field_mode ? v->ref_field_type[dir] : (((1<<fieldmv)+src_y - (s->mspel << fieldmv)) & 1)],
                                k, s->linesize << fieldmv);

         }
         srcY += s->mspel * (1 + (s->linesize << fieldmv));
     }
 
     if (s->mspel) {
         dxy = ((my & 3) << 2) | (mx & 3);
         if (avg)

             v->vc1dsp.avg_vc1_mspel_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize << fieldmv, v->rnd);

         else

             v->vc1dsp.put_vc1_mspel_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize << fieldmv, v->rnd);

     } else { // hpel mc - always used for luma
         dxy = (my & 2) | ((mx & 2) >> 1);
         if (!v->rnd)
             s->hdsp.put_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize, 8);
         else
             s->hdsp.put_no_rnd_pixels_tab[1][dxy](s->dest[0] + off, srcY, s->linesize, 8);
     }
 }
 
 /** Do motion compensation for 4-MV macroblock - both chroma blocks
  */
 void ff_vc1_mc_4mv_chroma(VC1Context *v, int dir)
 {
     MpegEncContext *s = &v->s;
     H264ChromaContext *h264chroma = &v->h264chroma;
     uint8_t *srcU, *srcV;
     int uvmx, uvmy, uvsrc_x, uvsrc_y;

     int16_t tx, ty;
     int chroma_ref_type;

     int v_edge_pos = s->v_edge_pos >> v->field_mode;
     uint8_t (*lutuv)[256];
     int use_ic;
 
     if (!v->field_mode && !v->s.last_picture.f->data[0])
         return;

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY)

         return;
 
     /* calculate chroma MV vector from four luma MVs */

     if (!v->field_mode || !v->numref) {
         int valid_count = get_chroma_mv(v, dir, &tx, &ty);

         if (!valid_count) {
             s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = 0;
             s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = 0;
             v->luma_mv[s->mb_x][0] = v->luma_mv[s->mb_x][1] = 0;
             return; //no need to do MC for intra blocks
         }

         chroma_ref_type = v->ref_field_type[dir];

     } else {

         int opp_count = get_luma_mv(v, dir, &tx, &ty);
         chroma_ref_type = v->cur_field_type ^ (opp_count > 2);

     }
     if (v->field_mode && chroma_ref_type == 1 && v->cur_field_type == 1 && !v->s.last_picture.f->data[0])
         return;
     s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][0] = tx;
     s->current_picture.motion_val[1][s->block_index[0] + v->blocks_off][1] = ty;
     uvmx = (tx + ((tx & 3) == 3)) >> 1;
     uvmy = (ty + ((ty & 3) == 3)) >> 1;
 
     v->luma_mv[s->mb_x][0] = uvmx;
     v->luma_mv[s->mb_x][1] = uvmy;
 
     if (v->fastuvmc) {
         uvmx = uvmx + ((uvmx < 0) ? (uvmx & 1) : -(uvmx & 1));
         uvmy = uvmy + ((uvmy < 0) ? (uvmy & 1) : -(uvmy & 1));
     }
     // Field conversion bias
     if (v->cur_field_type != chroma_ref_type)
         uvmy += 2 - 4 * chroma_ref_type;
 
     uvsrc_x = s->mb_x * 8 + (uvmx >> 2);
     uvsrc_y = s->mb_y * 8 + (uvmy >> 2);
 
     if (v->profile != PROFILE_ADVANCED) {
         uvsrc_x = av_clip(uvsrc_x, -8, s->mb_width  * 8);
         uvsrc_y = av_clip(uvsrc_y, -8, s->mb_height * 8);
     } else {
         uvsrc_x = av_clip(uvsrc_x, -8, s->avctx->coded_width  >> 1);
         uvsrc_y = av_clip(uvsrc_y, -8, s->avctx->coded_height >> 1);
     }
 
     if (!dir) {
         if (v->field_mode && (v->cur_field_type != chroma_ref_type) && v->second_field) {
             srcU = s->current_picture.f->data[1];
             srcV = s->current_picture.f->data[2];
             lutuv = v->curr_lutuv;

             use_ic = *v->curr_use_ic;

         } else {
             srcU = s->last_picture.f->data[1];
             srcV = s->last_picture.f->data[2];
             lutuv = v->last_lutuv;
             use_ic = v->last_use_ic;
         }
     } else {
         srcU = s->next_picture.f->data[1];
         srcV = s->next_picture.f->data[2];
         lutuv = v->next_lutuv;
         use_ic = v->next_use_ic;
     }
 
     if (!srcU) {
         av_log(v->s.avctx, AV_LOG_ERROR, "Referenced frame missing.\n");
         return;
     }
 
     srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
     srcV += uvsrc_y * s->uvlinesize + uvsrc_x;
 
     if (v->field_mode) {
         if (chroma_ref_type) {
             srcU += s->current_picture_ptr->f->linesize[1];
             srcV += s->current_picture_ptr->f->linesize[2];
         }
     }
 
     if (v->rangeredfrm || use_ic
         || s->h_edge_pos < 18 || v_edge_pos < 18
         || (unsigned)uvsrc_x > (s->h_edge_pos >> 1) - 9
         || (unsigned)uvsrc_y > (v_edge_pos    >> 1) - 9) {

         s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, srcU,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);

         s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer + 16, srcV,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1, uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);

         srcU = s->sc.edge_emu_buffer;
         srcV = s->sc.edge_emu_buffer + 16;

 
         /* if we deal with range reduction we need to scale source blocks */
         if (v->rangeredfrm) {

             vc1_scale_chroma(srcU, srcV, 9, s->uvlinesize);

         }
         /* if we deal with intensity compensation we need to scale source blocks */
         if (use_ic) {

             vc1_lut_scale_chroma(srcU, srcV,
                                  lutuv[v->field_mode ? chroma_ref_type : ((0 + uvsrc_y) & 1)],
                                  lutuv[v->field_mode ? chroma_ref_type : ((1 + uvsrc_y) & 1)],
                                  9, s->uvlinesize);

         }
     }
 
     /* Chroma MC always uses qpel bilinear */
     uvmx = (uvmx & 3) << 1;
     uvmy = (uvmy & 3) << 1;
     if (!v->rnd) {
         h264chroma->put_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         h264chroma->put_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
     } else {
         v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);
     }
 }
 
 /** Do motion compensation for 4-MV interlaced frame chroma macroblock (both U and V)
  */
 void ff_vc1_mc_4mv_chroma4(VC1Context *v, int dir, int dir2, int avg)
 {
     MpegEncContext *s = &v->s;
     H264ChromaContext *h264chroma = &v->h264chroma;
     uint8_t *srcU, *srcV;
     int uvsrc_x, uvsrc_y;
     int uvmx_field[4], uvmy_field[4];
     int i, off, tx, ty;
     int fieldmv = v->blk_mv_type[s->block_index[0]];

     static const uint8_t s_rndtblfield[16] = { 0, 0, 1, 2, 4, 4, 5, 6, 2, 2, 3, 8, 6, 6, 7, 12 };

     int v_dist = fieldmv ? 1 : 4; // vertical offset for lower sub-blocks
     int v_edge_pos = s->v_edge_pos >> 1;
     int use_ic;
     uint8_t (*lutuv)[256];
 

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY)

         return;
 
     for (i = 0; i < 4; i++) {
         int d = i < 2 ? dir: dir2;
         tx = s->mv[d][i][0];
         uvmx_field[i] = (tx + ((tx & 3) == 3)) >> 1;
         ty = s->mv[d][i][1];
         if (fieldmv)
             uvmy_field[i] = (ty >> 4) * 8 + s_rndtblfield[ty & 0xF];
         else
             uvmy_field[i] = (ty + ((ty & 3) == 3)) >> 1;
     }
 
     for (i = 0; i < 4; i++) {
         off = (i & 1) * 4 + ((i & 2) ? v_dist * s->uvlinesize : 0);
         uvsrc_x = s->mb_x * 8 +  (i & 1) * 4           + (uvmx_field[i] >> 2);
         uvsrc_y = s->mb_y * 8 + ((i & 2) ? v_dist : 0) + (uvmy_field[i] >> 2);
         // FIXME: implement proper pull-back (see vc1cropmv.c, vc1CROPMV_ChromaPullBack())
         uvsrc_x = av_clip(uvsrc_x, -8, s->avctx->coded_width  >> 1);
         uvsrc_y = av_clip(uvsrc_y, -8, s->avctx->coded_height >> 1);
         if (i < 2 ? dir : dir2) {

             srcU = s->next_picture.f->data[1];
             srcV = s->next_picture.f->data[2];

             lutuv  = v->next_lutuv;
             use_ic = v->next_use_ic;
         } else {

             srcU = s->last_picture.f->data[1];
             srcV = s->last_picture.f->data[2];

             lutuv  = v->last_lutuv;
             use_ic = v->last_use_ic;
         }

         if (!srcU)
             return;
         srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
         srcV += uvsrc_y * s->uvlinesize + uvsrc_x;

         uvmx_field[i] = (uvmx_field[i] & 3) << 1;
         uvmy_field[i] = (uvmy_field[i] & 3) << 1;
 

         if (fieldmv) {
             if (!(uvsrc_y & 1))
                 v_edge_pos = (s->v_edge_pos >> 1) - 1;
             else
                 uvsrc_y -= (uvsrc_y < 2);
         }

         if (use_ic
             || s->h_edge_pos < 10 || v_edge_pos < (5 << fieldmv)
             || (unsigned)uvsrc_x > (s->h_edge_pos >> 1) - 5
             || (unsigned)uvsrc_y > v_edge_pos - (5 << fieldmv)) {

             s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, srcU,

                                      s->uvlinesize, s->uvlinesize,
                                      5, (5 << fieldmv), uvsrc_x, uvsrc_y,
                                      s->h_edge_pos >> 1, v_edge_pos);

             s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer + 16, srcV,

                                      s->uvlinesize, s->uvlinesize,
                                      5, (5 << fieldmv), uvsrc_x, uvsrc_y,
                                      s->h_edge_pos >> 1, v_edge_pos);

             srcU = s->sc.edge_emu_buffer;
             srcV = s->sc.edge_emu_buffer + 16;

 
             /* if we deal with intensity compensation we need to scale source blocks */
             if (use_ic) {

                 vc1_lut_scale_chroma(srcU, srcV,
                                      lutuv[(uvsrc_y + (0 << fieldmv)) & 1],
                                      lutuv[(uvsrc_y + (1 << fieldmv)) & 1],
                                      5, s->uvlinesize << fieldmv);

             }
         }
         if (avg) {
             if (!v->rnd) {
                 h264chroma->avg_h264_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                 h264chroma->avg_h264_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
             } else {
                 v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                 v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
             }
         } else {
             if (!v->rnd) {
                 h264chroma->put_h264_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                 h264chroma->put_h264_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
             } else {
                 v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[1](s->dest[1] + off, srcU, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
                 v->vc1dsp.put_no_rnd_vc1_chroma_pixels_tab[1](s->dest[2] + off, srcV, s->uvlinesize << fieldmv, 4, uvmx_field[i], uvmy_field[i]);
             }
         }
     }
 }
 
 /** Motion compensation for direct or interpolated blocks in B-frames
  */
 void ff_vc1_interp_mc(VC1Context *v)
 {
     MpegEncContext *s = &v->s;
     H264ChromaContext *h264chroma = &v->h264chroma;
     uint8_t *srcY, *srcU, *srcV;
     int dxy, mx, my, uvmx, uvmy, src_x, src_y, uvsrc_x, uvsrc_y;
     int v_edge_pos = s->v_edge_pos >> v->field_mode;
     int use_ic = v->next_use_ic;
 
     if (!v->field_mode && !v->s.next_picture.f->data[0])
         return;
 
     mx   = s->mv[1][0][0];
     my   = s->mv[1][0][1];
     uvmx = (mx + ((mx & 3) == 3)) >> 1;
     uvmy = (my + ((my & 3) == 3)) >> 1;

     if (v->field_mode && v->cur_field_type != v->ref_field_type[1]) {
         my   = my   - 2 + 4 * v->cur_field_type;
         uvmy = uvmy - 2 + 4 * v->cur_field_type;

     }
     if (v->fastuvmc) {
         uvmx = uvmx + ((uvmx < 0) ? -(uvmx & 1) : (uvmx & 1));
         uvmy = uvmy + ((uvmy < 0) ? -(uvmy & 1) : (uvmy & 1));
     }
     srcY = s->next_picture.f->data[0];
     srcU = s->next_picture.f->data[1];
     srcV = s->next_picture.f->data[2];
 
     src_x   = s->mb_x * 16 + (mx   >> 2);
     src_y   = s->mb_y * 16 + (my   >> 2);
     uvsrc_x = s->mb_x *  8 + (uvmx >> 2);
     uvsrc_y = s->mb_y *  8 + (uvmy >> 2);
 
     if (v->profile != PROFILE_ADVANCED) {
         src_x   = av_clip(  src_x, -16, s->mb_width  * 16);
         src_y   = av_clip(  src_y, -16, s->mb_height * 16);
         uvsrc_x = av_clip(uvsrc_x,  -8, s->mb_width  *  8);
         uvsrc_y = av_clip(uvsrc_y,  -8, s->mb_height *  8);
     } else {
         src_x   = av_clip(  src_x, -17, s->avctx->coded_width);
         src_y   = av_clip(  src_y, -18, s->avctx->coded_height + 1);
         uvsrc_x = av_clip(uvsrc_x,  -8, s->avctx->coded_width  >> 1);
         uvsrc_y = av_clip(uvsrc_y,  -8, s->avctx->coded_height >> 1);
     }
 
     srcY += src_y   * s->linesize   + src_x;
     srcU += uvsrc_y * s->uvlinesize + uvsrc_x;
     srcV += uvsrc_y * s->uvlinesize + uvsrc_x;
 
     if (v->field_mode && v->ref_field_type[1]) {
         srcY += s->current_picture_ptr->f->linesize[0];
         srcU += s->current_picture_ptr->f->linesize[1];
         srcV += s->current_picture_ptr->f->linesize[2];
     }
 
     /* for grayscale we should not try to read from unknown area */

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY) {

         srcU = s->sc.edge_emu_buffer + 18 * s->linesize;
         srcV = s->sc.edge_emu_buffer + 18 * s->linesize;

     }
 
     if (v->rangeredfrm || s->h_edge_pos < 22 || v_edge_pos < 22 || use_ic
         || (unsigned)(src_x - 1) > s->h_edge_pos - (mx & 3) - 16 - 3
         || (unsigned)(src_y - 1) > v_edge_pos    - (my & 3) - 16 - 3) {

         uint8_t *ubuf = s->sc.edge_emu_buffer + 19 * s->linesize;

         uint8_t *vbuf = ubuf + 9 * s->uvlinesize;

         const int k = 17 + s->mspel * 2;

 
         srcY -= s->mspel * (1 + s->linesize);

         s->vdsp.emulated_edge_mc(s->sc.edge_emu_buffer, srcY,

                                  s->linesize, s->linesize,

                                  k, k,

                                  src_x - s->mspel, src_y - s->mspel,
                                  s->h_edge_pos, v_edge_pos);

         srcY = s->sc.edge_emu_buffer;

         s->vdsp.emulated_edge_mc(ubuf, srcU,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1,

                                  uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);
         s->vdsp.emulated_edge_mc(vbuf, srcV,

                                  s->uvlinesize, s->uvlinesize,
                                  8 + 1, 8 + 1,

                                  uvsrc_x, uvsrc_y,
                                  s->h_edge_pos >> 1, v_edge_pos >> 1);
         srcU = ubuf;
         srcV = vbuf;

         /* if we deal with range reduction we need to scale source blocks */
         if (v->rangeredfrm) {

             vc1_scale_luma(srcY, k, s->linesize);
             vc1_scale_chroma(srcU, srcV, 9, s->uvlinesize);

         }
 
         if (use_ic) {
             uint8_t (*luty )[256] = v->next_luty;
             uint8_t (*lutuv)[256] = v->next_lutuv;

             vc1_lut_scale_luma(srcY,
                                luty[v->field_mode ? v->ref_field_type[1] : ((0+src_y - s->mspel) & 1)],
                                luty[v->field_mode ? v->ref_field_type[1] : ((1+src_y - s->mspel) & 1)],
                                k, s->linesize);
             vc1_lut_scale_chroma(srcU, srcV,
                                  lutuv[v->field_mode ? v->ref_field_type[1] : ((0+uvsrc_y) & 1)],
                                  lutuv[v->field_mode ? v->ref_field_type[1] : ((1+uvsrc_y) & 1)],
                                  9, s->uvlinesize);

         }
         srcY += s->mspel * (1 + s->linesize);
     }
 
     if (s->mspel) {
         dxy = ((my & 3) << 2) | (mx & 3);

         v->vc1dsp.avg_vc1_mspel_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, v->rnd);

     } else { // hpel mc
         dxy = (my & 2) | ((mx & 2) >> 1);
 
         if (!v->rnd)

             s->hdsp.avg_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);

         else

             s->hdsp.avg_no_rnd_pixels_tab[dxy](s->dest[0], srcY, s->linesize, 16);

     }
 

     if (CONFIG_GRAY && s->avctx->flags & AV_CODEC_FLAG_GRAY)

         return;

     /* Chroma MC always uses qpel blilinear */
     uvmx = (uvmx & 3) << 1;
     uvmy = (uvmy & 3) << 1;
     if (!v->rnd) {

         h264chroma->avg_h264_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         h264chroma->avg_h264_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);

     } else {

         v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[0](s->dest[1], srcU, s->uvlinesize, 8, uvmx, uvmy);
         v->vc1dsp.avg_no_rnd_vc1_chroma_pixels_tab[0](s->dest[2], srcV, s->uvlinesize, 8, uvmx, uvmy);

     }
 }