| Message ID | 20210707154134.59769-1-gsun@roblox.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [FFmpeg-devel,1/3] avformat/oggparsevorbis: Update end_trimming for the last packet | expand |
| Context | Check | Description |
|---|---|---|
| andriy/x86_make | success | Make finished |
| andriy/x86_make_fate | fail | Make fate failed |
| andriy/PPC64_make | success | Make finished |
| andriy/PPC64_make_fate | warning | Make fate failed |
diff --git a/libavformat/oggparsevorbis.c b/libavformat/oggparsevorbis.c index 0e8c25c030..c48658ceda 100644 --- a/libavformat/oggparsevorbis.c +++ b/libavformat/oggparsevorbis.c @@ -492,8 +492,12 @@ static int vorbis_packet(AVFormatContext *s, int idx) priv->final_pts = os->lastpts; priv->final_duration = 0; } - if (os->segp == os->nsegs) + if (os->segp == os->nsegs) { + int64_t skip = priv->final_pts + priv->final_duration + os->pduration - os->granule; + if (skip > 0) + os->end_trimming = skip; os->pduration = os->granule - priv->final_pts - priv->final_duration; + } priv->final_duration += os->pduration; }
Without end_trimming, the last packet will contain unexpected samples used for padding. This commit partially fixes #6367 when the audio length is long enough. dd if=/dev/zero of=./silence.raw count=20 bs=500 oggenc --raw silence.raw --output=silence.ogg oggdec --raw --output silence.oggdec.raw silence.ogg ffmpeg -codec:a libvorbis -i silence.ogg -f s16le -codec:a pcm_s16le silence.libvorbis.ffmpeg.raw ffmpeg -i silence.ogg -f s16le -codec:a pcm_s16le silence.native.ffmpeg.raw ls -l *.raw The original test case in #6367 is still not fixed due to a remaining issue. The remaining issue is that ogg_stream->private is not kept during ogg_save()/ogg_restore(). Field final_duration in the private data is important to calculate end_trimming. Some common operations such as avformat_open_input() and avformat_find_stream_info() before reading packet will trigger ogg_save() and ogg_restore(). Luckily, final_duration will not get updated until the last ogg page. The save/restore mentioned above will not change final_duration most of the time. But if the audio length is short, those reads may be performed on the last ogg page, causing trouble keeping the correct value of final_duration. We probably need a more complicated patch to address this issue. Signed-off-by: Guangyu Sun <gsun@roblox.com> --- libavformat/oggparsevorbis.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)