Zhao Zhili <quinkbl...@foxmail.com> 于2023年9月12日周二 01:10写道： > > From: Zhao Zhili <zhiliz...@tencent.com> > > For bad interleaved files, manually interleave multiple tracks at the > demuxer level can trigger seeking back and forth, which can be > dramatically slow depending on the protocol. Demuxer level interleave > can be useless sometimes, e.g., reading mp4 via http and then > transcoding/remux to DASH. Disable this option when you don't need the > demuxer level interleave, and want to avoid the IO penalizes. > > Co-authored-by: Derek Buitenhuis <derek.buitenh...@gmail.com> > Signed-off-by: Zhao Zhili <zhiliz...@tencent.com> > --- > v3: update doc > v2: rename option > > This issue is well known. Two samples can be found at here > http://ffmpeg.org/pipermail/ffmpeg-devel/2022-December/304951.html > > doc/demuxers.texi | 7 +++++++ > libavformat/isom.h | 1 + > libavformat/mov.c | 5 ++++- > libavformat/version.h | 2 +- > 4 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/doc/demuxers.texi b/doc/demuxers.texi > index 2d33b47a56..ca1563abb0 100644 > --- a/doc/demuxers.texi > +++ b/doc/demuxers.texi > @@ -779,6 +779,13 @@ cast to int32 are used to adjust onward dts. > > Unit is the track time scale. Range is 0 to UINT_MAX. Default is > @code{UINT_MAX - 48000*10} which allows upto > a 10 second dts correction for 48 kHz audio streams while accommodating > 99.9% of @code{uint32} range. > + > +@item interleaved_read > +Interleave packets from multiple tracks at demuxer level. For badly > interleaved files, this prevents playback issues > +caused by large gaps between packets in different tracks, as MOV/MP4 do not > have packet placement requirements. > +However, this can cause excessive seeking on very badly interleaved files, > due to seeking between tracks, so disabling > +it may prevent I/O issues, at the expense of playback. > + > @end table > > @subsection Audible AAX > diff --git a/libavformat/isom.h b/libavformat/isom.h > index 4b1cd42f0f..3d375d7a46 100644 > --- a/libavformat/isom.h > +++ b/libavformat/isom.h > @@ -327,6 +327,7 @@ typedef struct MOVContext { > int64_t extent_offset; > } *avif_info; > int avif_info_size; > + int interleaved_read; > } MOVContext; > > int ff_mp4_read_descr_len(AVIOContext *pb); > diff --git a/libavformat/mov.c b/libavformat/mov.c > index aa1d9e4ccc..8ad5f0b646 100644 > --- a/libavformat/mov.c > +++ b/libavformat/mov.c > @@ -8780,6 +8780,8 @@ static AVIndexEntry > *mov_find_next_sample(AVFormatContext *s, AVStream **st) > AVIndexEntry *sample = NULL; > int64_t best_dts = INT64_MAX; > int i; > + MOVContext *mov = s->priv_data; > + int no_interleave = !mov->interleaved_read || !(s->pb->seekable & > AVIO_SEEKABLE_NORMAL); > for (i = 0; i < s->nb_streams; i++) { > AVStream *avst = s->streams[i]; > FFStream *const avsti = ffstream(avst); > @@ -8788,7 +8790,7 @@ static AVIndexEntry > *mov_find_next_sample(AVFormatContext *s, AVStream **st) > AVIndexEntry *current_sample = > &avsti->index_entries[msc->current_sample]; > int64_t dts = av_rescale(current_sample->timestamp, > AV_TIME_BASE, msc->time_scale); > av_log(s, AV_LOG_TRACE, "stream %d, sample %d, dts %"PRId64"\n", > i, msc->current_sample, dts); > - if (!sample || (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL) && > current_sample->pos < sample->pos) || > + if (!sample || (no_interleave && current_sample->pos < > sample->pos) || > ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && > ((msc->pb != s->pb && dts < best_dts) || (msc->pb == s->pb > && dts != AV_NOPTS_VALUE && > ((FFABS(best_dts - dts) <= AV_TIME_BASE && > current_sample->pos < sample->pos) || > @@ -9282,6 +9284,7 @@ static const AVOption mov_options[] = { > { "enable_drefs", "Enable external track support.", > OFFSET(enable_drefs), AV_OPT_TYPE_BOOL, > {.i64 = 0}, 0, 1, FLAGS }, > { "max_stts_delta", "treat offsets above this value as invalid", > OFFSET(max_stts_delta), AV_OPT_TYPE_INT, {.i64 = UINT_MAX-48000*10 }, 0, > UINT_MAX, .flags = AV_OPT_FLAG_DECODING_PARAM }, > + { "interleaved_read", "Manually interleave between multiple tracks", > OFFSET(interleaved_read), AV_OPT_TYPE_BOOL, {.i64 = 1 }, 0, 1, .flags = > AV_OPT_FLAG_DECODING_PARAM }, > > { NULL }, > }; > diff --git a/libavformat/version.h b/libavformat/version.h > index cb67e0a1f8..e41362ac9d 100644 > --- a/libavformat/version.h > +++ b/libavformat/version.h > @@ -32,7 +32,7 @@ > #include "version_major.h" > > #define LIBAVFORMAT_VERSION_MINOR 12 > -#define LIBAVFORMAT_VERSION_MICRO 100 > +#define LIBAVFORMAT_VERSION_MICRO 101 > > #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \ > LIBAVFORMAT_VERSION_MINOR, \ > -- > 2.34.1 > > _______________________________________________ > 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".
lgtm Thanks Steven _______________________________________________ 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".
