func: void ff_mspel_motion(MpegEncContext *s,
  
                                 uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr,
  
                                 uint8_t **ref_picture, op_pixels_func (*pix_op)[4],
  
                                 int motion_x, int motion_y, int h)
  
  {
  
      Wmv2Context * const w= (Wmv2Context*)s;
  
      uint8_t *ptr;
  
      int dxy, offset, mx, my, src_x, src_y, v_edge_pos, linesize, uvlinesize;
  
      int emu=0;
  
  
  
      dxy = ((motion_y & 1) << 1) | (motion_x & 1);
  
      dxy = 2*dxy + w->hshift;
  
      src_x = s->mb_x * 16 + (motion_x >> 1);
  
      src_y = s->mb_y * 16 + (motion_y >> 1);
  
  
  
      /* WARNING: do no forget half pels */
  
      v_edge_pos = s->v_edge_pos;
  
      src_x = av_clip(src_x, -16, s->width);
  
      src_y = av_clip(src_y, -16, s->height);
  
  
  
      if(src_x<=-16 || src_x >= s->width)
  
          dxy &= ~3;
  
      if(src_y<=-16 || src_y >= s->height)
  
          dxy &= ~4;
  
  
  
      linesize   = s->linesize;
  
      uvlinesize = s->uvlinesize;
  
      ptr = ref_picture[0] + (src_y * linesize) + src_x;
  
  
  
          if(src_x<1 || src_y<1 || src_x + 17  >= s->h_edge_pos
  
                                || src_y + h+1 >= v_edge_pos){
  
              s->vdsp.emulated_edge_mc(s->edge_emu_buffer, ptr - 1 - s->linesize, s->linesize, 19, 19,
  
                               src_x-1, src_y-1, s->h_edge_pos, s->v_edge_pos);
  
              ptr= s->edge_emu_buffer + 1 + s->linesize;
  
              emu=1;
  
          }
  
  
  
      s->dsp.put_mspel_pixels_tab[dxy](dest_y             , ptr             , linesize);
  
      s->dsp.put_mspel_pixels_tab[dxy](dest_y+8           , ptr+8           , linesize);
  
      s->dsp.put_mspel_pixels_tab[dxy](dest_y  +8*linesize, ptr  +8*linesize, linesize);
  
      s->dsp.put_mspel_pixels_tab[dxy](dest_y+8+8*linesize, ptr+8+8*linesize, linesize);
  
  
  
      if(s->flags&CODEC_FLAG_GRAY) return;
  
  
  
      if (s->out_format == FMT_H263) {
  
          dxy = 0;
  
          if ((motion_x & 3) != 0)
  
              dxy |= 1;
  
          if ((motion_y & 3) != 0)
  
              dxy |= 2;
  
          mx = motion_x >> 2;
  
          my = motion_y >> 2;
  
      } else {
  
          mx = motion_x / 2;
  
          my = motion_y / 2;
  
          dxy = ((my & 1) << 1) | (mx & 1);
  
          mx >>= 1;
  
          my >>= 1;
  
      }
  
  
  
      src_x = s->mb_x * 8 + mx;
  
      src_y = s->mb_y * 8 + my;
  
      src_x = av_clip(src_x, -8, s->width >> 1);
  
      if (src_x == (s->width >> 1))
  
          dxy &= ~1;
  
      src_y = av_clip(src_y, -8, s->height >> 1);
  
      if (src_y == (s->height >> 1))
  
          dxy &= ~2;
  
      offset = (src_y * uvlinesize) + src_x;
  
      ptr = ref_picture[1] + offset;
  
      if(emu){
  
          s->vdsp.emulated_edge_mc(s->edge_emu_buffer, ptr, s->uvlinesize, 9, 9,
  
                           src_x, src_y, s->h_edge_pos>>1, s->v_edge_pos>>1);
  
          ptr= s->edge_emu_buffer;
  
      }
  
      pix_op[1][dxy](dest_cb, ptr, uvlinesize, h >> 1);
  
  
  
      ptr = ref_picture[2] + offset;
  
      if(emu){
  
          s->vdsp.emulated_edge_mc(s->edge_emu_buffer, ptr, s->uvlinesize, 9, 9,
  
                           src_x, src_y, s->h_edge_pos>>1, s->v_edge_pos>>1);
  
          ptr= s->edge_emu_buffer;
  
      }
  
      pix_op[1][dxy](dest_cr, ptr, uvlinesize, h >> 1);
  
  }
  