The B predictor for 4-MV MBs in interlace field pictures is not used
for blocks 0 and 2 when the picture is 1 MB wide.
Signed-off-by: Jerome Borsboom <jerome.borsb...@carpalis.nl>
---
My 'shuffle calculation of MV predictor candidates' patch overlooked the
corner case of 1 MB wide field interlace pictures. According to VC-1 spec
and the reference decoder, the B predictor is not used for for block 0 and
block 2 when the picture is 1 MB wide. This patch corrects this.
libavcodec/vc1_pred.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libavcodec/vc1_pred.c b/libavcodec/vc1_pred.c
index e1758a3817..77dda86cd0 100644
--- a/libavcodec/vc1_pred.c
+++ b/libavcodec/vc1_pred.c
@@ -289,6 +289,8 @@ void ff_vc1_pred_mv(VC1Context *v, int n, int dmv_x, int
dmv_y,
case 3:
off = -1;
}
+ if (v->field_mode && s->mb_width == 1)
+ b_valid = b_valid && c_valid;
}
if (v->field_mode) {
--
2.13.6
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
