| Message ID | 20230923111034.6320-2-llyyr.public@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel] avformat/mov: avoid seeking back to 0 on HEVC open GOP files | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On 9/23/23 16:40, llyyr wrote: > ab77b878f1 attempted to fix the issue of broken packets being sent to > the decoder by implementing logic that kept attempting to PTS-step > backwards until it reached a valid point, however applying this > heuristic meant that in files that had no valid points (such as HEVC > videos shot on iPhones), we'd seek back to sample 0 on every seek > attempt. This meant that files that were previously seekable, albeit > with some skipped frames, were not seekable at all now. > > Relax this heuristic a bit by giving up on seeking to a valid point if > we've tried a different sample and we still don't have a valid point to > seek to. This may some frames to be skipped on seeking but it's better > than not being able to seek at all in such files. > > Fixes: ab77b878f1 ("avformat/mov: fix seeking with HEVC open GOP files") > --- > libavformat/mov.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/libavformat/mov.c b/libavformat/mov.c > index 1996e0028c..60a4d581d9 100644 > --- a/libavformat/mov.c > +++ b/libavformat/mov.c > @@ -9108,7 +9108,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp, > { > MOVStreamContext *sc = st->priv_data; > FFStream *const sti = ffstream(st); > - int sample, time_sample, ret; > + int sample, time_sample, ret, next_ts, requested_sample; > unsigned int i; > > // Here we consider timestamp to be PTS, hence try to offset it so that we > @@ -9129,7 +9129,17 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp, > > if (!sample || can_seek_to_key_sample(st, sample, timestamp)) > break; > - timestamp -= FFMAX(sc->min_sample_duration, 1); > + > + next_ts = timestamp - FFMAX(sc->min_sample_duration, 1); > + requested_sample = av_index_search_timestamp(st, next_ts, flags); > + > + // If we can't seek to the next pts either and it's a different sample, > + // give up trying to find a good pts to seek to, otherwise we'll end up > + // seeking back to sample 0 on every seek. > + if (!can_seek_to_key_sample(st, requested_sample, next_ts) && sample != requested_sample) > + break; > + > + timestamp = next_ts; > } > > mov_current_sample_set(sc, sample); Pinging this as it seems to have been missed. The patch still applies on current master and the issue also still exists.
diff --git a/libavformat/mov.c b/libavformat/mov.c index 1996e0028c..60a4d581d9 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -9108,7 +9108,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp, { MOVStreamContext *sc = st->priv_data; FFStream *const sti = ffstream(st); - int sample, time_sample, ret; + int sample, time_sample, ret, next_ts, requested_sample; unsigned int i; // Here we consider timestamp to be PTS, hence try to offset it so that we @@ -9129,7 +9129,17 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp, if (!sample || can_seek_to_key_sample(st, sample, timestamp)) break; - timestamp -= FFMAX(sc->min_sample_duration, 1); + + next_ts = timestamp - FFMAX(sc->min_sample_duration, 1); + requested_sample = av_index_search_timestamp(st, next_ts, flags); + + // If we can't seek to the next pts either and it's a different sample, + // give up trying to find a good pts to seek to, otherwise we'll end up + // seeking back to sample 0 on every seek. + if (!can_seek_to_key_sample(st, requested_sample, next_ts) && sample != requested_sample) + break; + + timestamp = next_ts; } mov_current_sample_set(sc, sample);
ab77b878f1 attempted to fix the issue of broken packets being sent to the decoder by implementing logic that kept attempting to PTS-step backwards until it reached a valid point, however applying this heuristic meant that in files that had no valid points (such as HEVC videos shot on iPhones), we'd seek back to sample 0 on every seek attempt. This meant that files that were previously seekable, albeit with some skipped frames, were not seekable at all now. Relax this heuristic a bit by giving up on seeking to a valid point if we've tried a different sample and we still don't have a valid point to seek to. This may some frames to be skipped on seeking but it's better than not being able to seek at all in such files. Fixes: ab77b878f1 ("avformat/mov: fix seeking with HEVC open GOP files") --- libavformat/mov.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)