Sure, changed in PATCH v4. ________________________________ 发件人: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> 代表 Michael Niedermayer <mich...@niedermayer.cc> 发送时间: 2024年12月23日 5:41 收件人: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> 主题: Re: [FFmpeg-devel] [PATCH v3] avcodec/h264_mb: Fix tmp buffer overlap in mc_part_weighted
On Fri, Dec 20, 2024 at 01:26:37PM +0800, Bin Peng wrote: > When decoding a bitstream with weighted-bipred enabled, > the results on ARM and x86 platforms may differ. > > The reason for the inconsistency is that the value of > STRIDE_ALIGN differs between platforms. And STRIDE_ALIGN > is set to the buffer stride of temporary buffers for U > and V components in mc_part_weighted. > > If the buffer stride is 32 or 64 (as on x86 platforms), > the U and V pixels can be interleaved row by row without > overlapping, resulting in correct output. > However, on ARM platforms where the stride is 16, > the V component will overwrite part of the U component's pixels, > leading to incorrect predicted pixels. > > Fixes: ticket 11357 > > Signed-off-by: Bin Peng <peng...@visionular.com> > --- > libavcodec/h264_mb.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/libavcodec/h264_mb.c b/libavcodec/h264_mb.c > index 4e94136313..b480cd312b 100644 > --- a/libavcodec/h264_mb.c > +++ b/libavcodec/h264_mb.c > @@ -407,8 +407,8 @@ static av_always_inline void mc_part_weighted(const > H264Context *h, H264SliceCon > /* don't optimize for luma-only case, since B-frames usually > * use implicit weights => chroma too. */ > uint8_t *tmp_cb = sl->bipred_scratchpad; > - uint8_t *tmp_cr = sl->bipred_scratchpad + (16 << pixel_shift); > - uint8_t *tmp_y = sl->bipred_scratchpad + 16 * sl->mb_uvlinesize; > + uint8_t *tmp_cr = sl->bipred_scratchpad + (16 * sl->mb_uvlinesize); > + uint8_t *tmp_y = sl->bipred_scratchpad + (32 * sl->mb_uvlinesize); larger seperation wil decrease cache utilization and worsen speed. cant we make sure stride is at least 32 without forcing alignment by 32 ? thx [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Republics decline into democracies and democracies degenerate into despotisms. -- Aristotle _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
