ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinha...@outlook.com> | Mon Aug 8 16:51:04 2022 +0200| [71ff9217f769b03ce3b8081ad596ed777ac24d2f] | committer: Andreas Rheinhardt
avcodec/mpegpicture: Always reset motion val buffer Codecs call ff_find_unused_picture() to get the index of an unused picture; said picture may have buffers left from using it previously (these buffers are intentionally not unreferenced so that it might be possible to reuse them; this is mpegvideo's version of a bufferpool). They should not make any assumptions about which picture they get. Yet somehow this is not true when decoding OBMC: Returning random empty pictures (instead of the first one) leads to nondeterministic results; similarly, explicitly rezeroing the buffer before handing it over to the codec changes the outcome of the h263-obmc tests, but it makes it independent of the returned pictures. Therefore this commit does so. Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=71ff9217f769b03ce3b8081ad596ed777ac24d2f --- libavcodec/mpegpicture.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/mpegpicture.c b/libavcodec/mpegpicture.c index 88b4d5dec1..06c82880a8 100644 --- a/libavcodec/mpegpicture.c +++ b/libavcodec/mpegpicture.c @@ -245,6 +245,10 @@ int ff_alloc_picture(AVCodecContext *avctx, Picture *pic, MotionEstContext *me, for (i = 0; i < 2; i++) { pic->motion_val[i] = (int16_t (*)[2])pic->motion_val_buf[i]->data + 4; pic->ref_index[i] = pic->ref_index_buf[i]->data; + /* FIXME: The output of H.263 with OBMC depends upon + * the earlier content of the buffer; therefore we + * reset it here. */ + memset(pic->motion_val_buf[i]->data, 0, pic->motion_val_buf[i]->size); } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
