From dd2d0039b6405dc724e4fef0d5b8f49530eea3aa Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 19 Jan 2014 15:28:25 +0000 Subject: [PATCH] vc1: Always reset numref when parsing a new frame header. Fixes an issue where the B-frame coding mode switches from interlaced fields to interlaced frames, causing incorrect decisions in the motion compensation code and resulting in visual artifacts. CC: libav-stable@libav.org Signed-off-by: Tim Walker --- libavcodec/vc1.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c index acefce695e..a7f2aab209 100644 --- a/libavcodec/vc1.c +++ b/libavcodec/vc1.c @@ -842,6 +842,7 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb) int mbmodetab, imvtab, icbptab, twomvbptab, fourmvbptab; /* useful only for debugging */ int field_mode, fcm; + v->numref = 0; v->p_frame_skipped = 0; if (v->second_field) { v->s.pict_type = (v->fptype & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I; @@ -1011,8 +1012,6 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb) v->reffield = get_bits1(gb); v->ref_field_type[0] = v->reffield ^ !v->cur_field_type; } - } else { - v->numref = 0; } if (v->extended_mv) v->mvrange = get_unary(gb, 0, 3);