vismv for h264 displayed incorrect motion vectors.

Originally committed as revision 3765 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -203,7 +203,7 @@ typedef struct H264Context{
     
     uint16_t *mb2b_xy; //FIXME are these 4 a good idea?
     uint16_t *mb2b8_xy;
-    int b_stride;
+    int b_stride; //FIXME use s->b4_stride
     int b8_stride;
 
     int halfpel_flag;
@@ -3035,8 +3035,8 @@ static int decode_slice_header(H264Context *h){
     s->mb_width= h->sps.mb_width;
     s->mb_height= h->sps.mb_height;
     
-    h->b_stride=  s->mb_width*4;
-    h->b8_stride= s->mb_width*2;
+    h->b_stride=  s->mb_width*4 + 1;
+    h->b8_stride= s->mb_width*2 + 1;
 
     s->resync_mb_x = s->mb_x = first_mb_in_slice % s->mb_width;
     s->resync_mb_y = s->mb_y = first_mb_in_slice / s->mb_width; //FIXME AFFW

libavcodec/mpegvideo.c

@@ -1762,6 +1762,8 @@ void ff_print_debug_info(MpegEncContext *s, AVFrame *pict){
         int h_chroma_shift, v_chroma_shift;
         const int width = s->avctx->width;
         const int height= s->avctx->height;
+        const int mv_sample_log2= 4 - pict->motion_subsample_log2;
+        const int mv_stride= (s->mb_width << mv_sample_log2) + 1;
         s->low_delay=0; //needed to see the vectors without trashing the buffers
 
         avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &h_chroma_shift, &v_chroma_shift);
@@ -1797,13 +1799,12 @@ void ff_print_debug_info(MpegEncContext *s, AVFrame *pict){
                     if(!USES_LIST(pict->mb_type[mb_index], direction))
                         continue;
 
-                    //FIXME for h264
                     if(IS_8X8(pict->mb_type[mb_index])){
                       int i;
                       for(i=0; i<4; i++){
                         int sx= mb_x*16 + 4 + 8*(i&1);
                         int sy= mb_y*16 + 4 + 8*(i>>1);
-                        int xy= mb_x*2 + (i&1) + (mb_y*2 + (i>>1))*s->b8_stride;
+                        int xy= (mb_x*2 + (i&1) + (mb_y*2 + (i>>1))*mv_stride) << mv_sample_log2-1;
                         int mx= (pict->motion_val[direction][xy][0]>>shift) + sx;
                         int my= (pict->motion_val[direction][xy][1]>>shift) + sy;
                         draw_arrow(ptr, sx, sy, mx, my, width, height, s->linesize, 100);
@@ -1813,7 +1814,21 @@ void ff_print_debug_info(MpegEncContext *s, AVFrame *pict){
                       for(i=0; i<2; i++){
                         int sx=mb_x*16 + 8;
                         int sy=mb_y*16 + 4 + 8*i;
-                        int xy= mb_x*2 + (mb_y*2 + i)*s->b8_stride;
+                        int xy= (mb_x*2 + (mb_y*2 + i)*mv_stride) << mv_sample_log2-1;
+                        int mx=(pict->motion_val[direction][xy][0]>>shift);
+                        int my=(pict->motion_val[direction][xy][1]>>shift);
+                        
+                        if(IS_INTERLACED(pict->mb_type[mb_index]))
+                            my*=2;
+                        
+                        draw_arrow(ptr, sx, sy, mx+sx, my+sy, width, height, s->linesize, 100);
+                      }
+                    }else if(IS_8X16(pict->mb_type[mb_index])){
+                      int i;
+                      for(i=0; i<2; i++){
+                        int sx=mb_x*16 + 4 + 8*i;
+                        int sy=mb_y*16 + 8;
+                        int xy= (mb_x*2 + i + mb_y*2*mv_stride) << mv_sample_log2-1;
                         int mx=(pict->motion_val[direction][xy][0]>>shift);
                         int my=(pict->motion_val[direction][xy][1]>>shift);
                         
@@ -1825,7 +1840,7 @@ void ff_print_debug_info(MpegEncContext *s, AVFrame *pict){
                     }else{
                       int sx= mb_x*16 + 8;
                       int sy= mb_y*16 + 8;
-                      int xy= mb_x*2 + mb_y*2*s->b8_stride;
+                      int xy= (mb_x + mb_y*mv_stride) << mv_sample_log2;
                       int mx= (pict->motion_val[direction][xy][0]>>shift) + sx;
                       int my= (pict->motion_val[direction][xy][1]>>shift) + sy;
                       draw_arrow(ptr, sx, sy, mx, my, width, height, s->linesize, 100);