>De : Nicolas Gaullier <nicolas.gaullier@cji.paris> >Envoyé : mardi 2 avril 2024 23:26 >Objet : [PATCH v3 0/1] avformat/demux: fix accurate probing of durations in >mpegts/ps > >v3: rebased after ed9363052f4b8b8 applied tonight (add duration_probesize >AVOption) > >Note: I have no other plan for demux/probing; with these two patches, I can >cover my use cases, especially mpegts-concats. > >For remembering, previous cover-letters: > >v1-------------------- >ff_read_packet() is more lightweight, but it leads to important issues when >looking for accurate durations. >As a side effect, the code looks also simpler with regular av_read_frame() >calls. >1)Updates in the fate tests do exhibit most of the results. > >2)See also more directly the case of an audio PES containing many frames: >>ffprobe tests/data/lavf/lavf.ts -select_streams a -show_entries >>stream=duration -of flat >Before patch: > streams.stream.0.duration="0.757556" >After patch: > streams.stream.0.duration="1.018778" > >3)Here is an additional (commonplace) sample to demonstrate the benefit for >twofields-encoded video: >>https://0x0.st/HFbm.ts (say h264-50i_mp2.ts) > >>ffprobe h264-50i_mp2.ts -show_entries stream=duration -of flat >Before patch: > streams.stream.0.duration="2.060000" > streams.stream.1.duration="1.176000" >After patch: > streams.stream.0.duration="2.080000" > streams.stream.1.duration="1.200000" > > >v2-------------------- >v1: There was an issue with teletext where resolution is set just once at >decoder init (teletext resolution is fixed/hard coded), so it is somewhat >fragile: when a demuxer context update occurs, it is lost/overriden by >>avcodec_parameters_to_context(sti->avctx, st->codecpar) in >read_frame_internal. >They could have been other scenario besides teletext, I don't know. >v2: So now at estimate_timings_from_pts, with one or more seeking involved >(seeking is detected by the mpegts demuxer and set last_vn=-1, so pmt is >forced/updated and results in demuxer context update), it is required to >>preserve the info in codecpar at first. >Thanks to Michael for reporting the issue. > > >Nicolas Gaullier (1): > avformat/demux: Fix accurate probing of durations in mpegts/ps > > libavformat/demux.c | 36 ++-- > tests/ref/fate/concat-demuxer-simple2-lavf-ts | 170 +++++++++--------- > tests/ref/fate/ts-opus-demux | 4 +- > 3 files changed, 100 insertions(+), 110 deletions(-)
Ping for review ? The patch (https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=11386) still applies on current master. Thanks. Nicolas _______________________________________________ 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".
