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| author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2022-08-09 16:36:16 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2022-08-10 18:49:35 +0200 |
| commit | 0a06f5aca5edf04c94860381e7ef9d65b9dab193 (patch) | |
| tree | b91c7cde425322e0c08ab3bfedb99d21a54d2cbe /libavcodec/wmv2dec.c | |
| parent | 193c40259e9ed9233256f1a3080b70c3e5bc609a (diff) | |
| download | ffmpeg-0a06f5aca5edf04c94860381e7ef9d65b9dab193.tar.gz | |
avcodec/wmv2dec: Zero mb_type array for I pictures
Up until now, ff_wmv2_decode_secondary_picture_header() only
set the mb_type array for non I-pictures, so that the decoding
process uses the earlier values of this array; this affects
the output of the wmv8-x8intra FATE-test (which this patch
therefore updates). These earlier values were set when decoding
earlier frames or when the buffer was initially zero-allocated.
A consequence of this is that the output of this test would be
random if ff_find_unused_picture() would select the unused picture
to return at random. Furthermore decoding from a keyframe onwards
depends upon the earlier state of the decoder.
This patch therefore zeroes said array when decoding an I picture.
(It is not claimed that zero is the right value to fill the array with.
I just don't know.)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec/wmv2dec.c')
| -rw-r--r-- | libavcodec/wmv2dec.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libavcodec/wmv2dec.c b/libavcodec/wmv2dec.c index 6d9b72d123..22eb012f56 100644 --- a/libavcodec/wmv2dec.c +++ b/libavcodec/wmv2dec.c @@ -242,6 +242,10 @@ int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s) WMV2DecContext *const w = (WMV2DecContext *) s; if (s->pict_type == AV_PICTURE_TYPE_I) { + /* Is filling with zeroes really the right thing to do? */ + memset(s->current_picture_ptr->mb_type, 0, + sizeof(*s->current_picture_ptr->mb_type) * + s->mb_height * s->mb_stride); if (w->j_type_bit) w->j_type = get_bits1(&s->gb); else |