[FFmpeg-devel] [PATCH] avformat/mpegts: Add -reprobe_stream_if_pmt_es_stream_type_changes option

[Michael Niedermayer]

Hi Andreas

On Sun, Jun 15, 2025 at 05:24:34AM +0200, Andreas Rheinhardt wrote:
> Pavel Koshevoy:
> > Make runtime AVStream.codecpar codec_id updates optional and disabled
> > by default, so that avformat API clients can enable this feature explicitly
> > when they add support for runtime codec changes.
> > ---
> >  libavformat/mpegts.c | 8 +++++++-
> >  tests/fate/demux.mak | 2 +-
> >  2 files changed, 8 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> > index deb69a0548..88b1754307 100644
> > --- a/libavformat/mpegts.c
> > +++ b/libavformat/mpegts.c
> > @@ -156,6 +156,8 @@ struct MpegTSContext {
> >      /** to detect seek */
> >      int64_t last_pos;
> >  
> > +    int reprobe_stream_if_pmt_es_stream_type_changes;
> > +
> >      int skip_changes;
> >      int skip_clear;
> >      int skip_unknown_pmt;
> > @@ -199,6 +201,8 @@ static const AVOption options[] = {
> >      MPEGTS_OPTIONS,
> >      {"fix_teletext_pts", "try to fix pts values of dvb teletext streams", offsetof(MpegTSContext, fix_teletext_pts), AV_OPT_TYPE_BOOL,
> >       {.i64 = 1}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
> > +    {"reprobe_stream_if_pmt_es_stream_type_changes", "allow PMT updates to change codec_type and codec_id at runtime",
> > +     offsetof(MpegTSContext, reprobe_stream_if_pmt_es_stream_type_changes), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
> >      {"scan_all_pmts", "scan and combine all PMTs", offsetof(MpegTSContext, scan_all_pmts), AV_OPT_TYPE_BOOL,
> >       {.i64 = -1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM },
> >      {"skip_unknown_pmt", "skip PMTs for programs not advertised in the PAT", offsetof(MpegTSContext, skip_unknown_pmt), AV_OPT_TYPE_BOOL,
> > @@ -2510,7 +2514,9 @@ static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len
> >          if (!st)
> >              goto out;
> >  
> > -        if (pes && pes->stream_type != stream_type)
> > +        if (pes && (!pes->stream_type ||
> > +                    (pes->stream_type != stream_type &&
> > +                     ts->reprobe_stream_if_pmt_es_stream_type_changes)))
> >              mpegts_set_stream_info(st, pes, stream_type, prog_reg_desc);
> >  
> >          add_pid_to_program(prg, pid);
> > diff --git a/tests/fate/demux.mak b/tests/fate/demux.mak
> > index ead5ad4b10..6e5e2eb81a 100644
> > --- a/tests/fate/demux.mak
> > +++ b/tests/fate/demux.mak
> > @@ -158,7 +158,7 @@ FATE_SAMPLES_DEMUX-$(CONFIG_XWMA_DEMUXER) += fate-xwma-demux
> >  fate-xwma-demux: CMD = crc -i $(TARGET_SAMPLES)/xwma/ergon.xwma -c:a copy
> >  
> >  FATE_FFPROBE_DEMUX-$(CONFIG_MPEGTS_DEMUXER) += fate-ts-demux
> > -fate-ts-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/ac3/mp3ac325-4864-small.ts
> > +fate-ts-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/ac3/mp3ac325-4864-small.ts -reprobe_stream_if_pmt_es_stream_type_changes 1
> >  
> >  FATE_FFPROBE_DEMUX-$(CONFIG_MPEGTS_DEMUXER) += fate-ts-timed-id3-demux
> >  fate-ts-timed-id3-demux: CMD = ffprobe_demux $(TARGET_SAMPLES)/mpegts/id3.ts
> 
> IMO this should not be mpegts specific, but for all demuxers. Other
> (header-less) formats may have the same issue.

+1

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
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