MPEG-TS encoder may stop emitting SDT/PAT/PMT after DTS jump or rollover

[Jernej Virag]

When transcoding broadcast MPEG-TS streams, there may be jumps or a rollover in PTS/DTS values in stream. That's perfectly valid, however ffmpeg's MPEG-TS muxer may stop emitting SDT/PAT/PMT tables.

The issue was tracked down to retransmit_si_info method where two following comparisons are made:

...
        (dts != AV_NOPTS_VALUE && dts - ts->last_sdt_ts >= ts->sdt_period*90000.0)
...
        if (dts != AV_NOPTS_VALUE)
            ts->last_sdt_ts = FFMAX(dts, ts->last_sdt_ts);

...

        (dts != AV_NOPTS_VALUE && dts - ts->last_pat_ts >= ts->pat_period*90000.0) ||
...
        if (dts != AV_NOPTS_VALUE)
            ts->last_pat_ts = FFMAX(dts, ts->last_pat_ts);

All those comparisons fail to take into account the possibility of DTS regressing which means a negative DTS jump will cause the muxer to stop emitting SDT tables alltogether in all streams and PAT/PMT tables alltogether in audio-only streams.

[Balling]

There was this aa20294b317558957cf124bb8e4da0521ab3c423 (and fixit) aa20294b317558957cf124bb8e4da0521ab3c423

What else has to be done to fix it?