VC1: Do qpel when needed for both MVs in a B frame

Originally committed as revision 18511 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 14 insertions, 4 deletions

diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index ef6f8b278a..7d0387eb08 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -1904,11 +1904,21 @@ static void vc1_interp_mc(VC1Context *v)
         srcY += s->mspel * (1 + s->linesize);
     }
 
-    mx >>= 1;
-    my >>= 1;
-    dxy = ((my & 1) << 1) | (mx & 1);
+    if(s->mspel) {
+        dxy = ((my & 3) << 2) | (mx & 3);
+        dsp->avg_vc1_mspel_pixels_tab[dxy](s->dest[0]    , srcY    , s->linesize, v->rnd);
+        dsp->avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8, srcY + 8, s->linesize, v->rnd);
+        srcY += s->linesize * 8;
+        dsp->avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8 * s->linesize    , srcY    , s->linesize, v->rnd);
+        dsp->avg_vc1_mspel_pixels_tab[dxy](s->dest[0] + 8 * s->linesize + 8, srcY + 8, s->linesize, v->rnd);
+    } else { // hpel mc
+        dxy = (my & 2) | ((mx & 2) >> 1);
 
-    dsp->avg_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);
+        if(!v->rnd)
+            dsp->avg_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);
+        else
+            dsp->avg_no_rnd_pixels_tab[0][dxy](s->dest[0], srcY, s->linesize, 16);
+    }
 
     if(s->flags & CODEC_FLAG_GRAY) return;
     /* Chroma MC always uses qpel blilinear */