DMV support patch by ("Ivan Kalvachev" <ivan at cacad dot com>)

Originally committed as revision 1985 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mpeg12.c

@@ -1108,34 +1108,37 @@ static int mpeg_decode_mb(MpegEncContext *s,
                                                     s->last_mv[i][0][1] >> 1);
                             dmy = get_dmv(s);
                             s->mv_type = MV_TYPE_DMV;
-                            /* XXX: totally broken */
+
+
+                            s->last_mv[i][0][1] = my<<1;
+                            s->last_mv[i][1][1] = my<<1;
+
+                            s->mv[i][0][0] = mx;
+                            s->mv[i][0][1] = my;
+                            s->mv[i][1][0] = mx;//not used
+                            s->mv[i][1][1] = my;//not used
+
                             if (s->picture_structure == PICT_FRAME) {
                                 mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED; 
 
-                                s->last_mv[i][0][1] = my << 1;
-                                s->last_mv[i][1][1] = my << 1;
-
+                                //m = 1 + 2 * s->top_field_first;
                                 m = s->top_field_first ? 1 : 3;
+
                                 /* top -> top pred */
-                                s->mv[i][0][0] = mx; 
-                                s->mv[i][0][1] = my << 1;
-                                s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
-                                s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
+                                s->mv[i][2][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
+                                s->mv[i][2][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
                                 m = 4 - m;
-                                s->mv[i][2][0] = mx;
-                                s->mv[i][2][1] = my << 1;
                                 s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
                                 s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
                             } else {
                                 mb_type |= MB_TYPE_16x16;
 
-                                s->last_mv[i][0][1] = my;
-                                s->last_mv[i][1][1] = my;
-                                s->mv[i][0][0] = mx;
-                                s->mv[i][0][1] = my;
-                                s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
-                                s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1 
-                                    /* + 2 * cur_field */;
+                                s->mv[i][2][0] = ((mx + (mx > 0)) >> 1) + dmx;
+                                s->mv[i][2][1] = ((my + (my > 0)) >> 1) + dmy;
+                                if(s->picture_structure == PICT_TOP_FIELD)
+                                    s->mv[i][2][1]--;
+                                else 
+                                    s->mv[i][2][1]++;
                             }
                         }
                         break;

libavcodec/mpegvideo.c

@@ -2190,6 +2190,71 @@ static inline void MPV_motion(MpegEncContext *s,
                         s->mv[dir][0][0], s->mv[dir][0][1], 16);
         }
         break;
+    case MV_TYPE_DMV:
+    {
+    op_pixels_func (*dmv_pix_op)[4];
+    int offset;
+
+        dmv_pix_op = s->dsp.put_pixels_tab;
+
+        if(s->picture_structure == PICT_FRAME){
+            //put top field from top field
+            mpeg_motion(s, dest_y, dest_cb, dest_cr, 0,
+                        ref_picture, 0,
+                        1, dmv_pix_op,
+                        s->mv[dir][0][0], s->mv[dir][0][1], 8);
+            //put bottom field from bottom field
+            mpeg_motion(s, dest_y, dest_cb, dest_cr, s->linesize,
+                        ref_picture, s->linesize,
+                        1, dmv_pix_op,
+                        s->mv[dir][0][0], s->mv[dir][0][1], 8);
+
+            dmv_pix_op = s->dsp.avg_pixels_tab; 
+        
+            //avg top field from bottom field
+            mpeg_motion(s, dest_y, dest_cb, dest_cr, 0,
+                        ref_picture, s->linesize,
+                        1, dmv_pix_op,
+                        s->mv[dir][2][0], s->mv[dir][2][1], 8);
+            //avg bottom field from top field
+            mpeg_motion(s, dest_y, dest_cb, dest_cr, s->linesize,
+                        ref_picture, 0,
+                        1, dmv_pix_op,
+                        s->mv[dir][3][0], s->mv[dir][3][1], 8);
+
+        }else{
+            offset=(s->picture_structure == PICT_BOTTOM_FIELD)? 
+                         s->linesize : 0;
+
+            //put field from the same parity
+            //same parity is never in the same frame
+            mpeg_motion(s, dest_y, dest_cb, dest_cr, 0,
+                        ref_picture,offset,
+                        0,dmv_pix_op,
+                        s->mv[dir][0][0],s->mv[dir][0][1],16);
+
+            // after put we make avg of the same block
+            dmv_pix_op=s->dsp.avg_pixels_tab; 
+
+            //opposite parity is always in the same frame if this is second field
+            if(!s->first_field){
+                ref_picture = s->current_picture.data;    
+                //top field is one linesize from frame beginig
+                offset=(s->picture_structure == PICT_BOTTOM_FIELD)? 
+                        -s->linesize : s->linesize;
+            }else 
+                offset=(s->picture_structure == PICT_BOTTOM_FIELD)? 
+                        0 : s->linesize;
+
+            //avg field from the opposite parity
+            mpeg_motion(s, dest_y, dest_cb, dest_cr,0,
+                        ref_picture, offset,
+                        0,dmv_pix_op,
+                        s->mv[dir][2][0],s->mv[dir][2][1],16);
+        }
+    }
+    break;
+
     }
 }