dvb teletext broken output with scodec copy after 26.5 hours

[Dennis E. Mungai]

Summary of the bug:

How to reproduce:

Here is a trivial example demonstrating the issue.

This occurs with or without the use of -copyts and other flags:

ffmpeg -nostdin -analyzeduration 1000000 -fflags +genpts+igndts -threads:v 1 -copyts -start_at_zero -copytb 1 -i "udp://$address:$port?fifo_size=2000000&buffer_size=500000&overrun_nonfatal=1" -flags -global_header -scodec copy -map 0:s -f mpegts "udp://$address:$port?pkt_size=1316&ttl=0"

This was tested on git master, and releases 4.3,4.4,5.0 and 6.0, and remains consistently reproducible.

The process(es) fail with the typical log:

[mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615604, current: 25924520; changing to 8584615605. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.583981663Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615605, current: 25926742; changing to 8584615606. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.617813181Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615606, current: 25931209; changing to 8584615607. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.660480003Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615607, current: 25933454; changing to 8584615608. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.705600374Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615608, current: 25937898; changing to 8584615609. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.745257948Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615609, current: 25942354; changing to 8584615610. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.792956919Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615610, current: 25946798; changing to 8584615611. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.826549269Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615611, current: 25949043; changing to 8584615612. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.863288436Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615612, current: 25953499; changing to 8584615613. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.898381018Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615613, current: 25955721; changing to 8584615614. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.943112768Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615614, current: 25960176; changing to 8584615615. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:41.990957430Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615615, current: 25962421; changing to 8584615616. This may result in incorrect timestamps in the output file.
[mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615616, current: 25966877; changing to 8584615617. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.068399496Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615617, current: 25971321; changing to 8584615618. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.104472785Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615618, current: 25973554; changing to 8584615619. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.139226689Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615619, current: 25978010; changing to 8584615620. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.186078743Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615620, current: 25980244; changing to 8584615621. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.220072406Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615621, current: 25984699; changing to 8584615622. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.271244514Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615622, current: 25988726; changing to 8584615623. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.301641546Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615623, current: 25990948; changing to 8584615624. This may result in incorrect timestamps in the output file.
2023-05-30T20:01:42.352140743Z [mpegts @ 0x5561f3c23200] Non-monotonous DTS in output stream 0:0; previous: 8584615624, current: 25995404; changing to 8584615625. This may result in incorrect timestamps in the output file.

I've also tried setting the mpegts demuxer option -fix_teletext_pts 0 to no avail,with the same failure message. This option was highlighted in ticket #8844 as a potential workaround.

When the "Non-monotonous DTS in output stream" warning(s) occur, the subtitle stream(s) are no longer accessible on the output.

Regrettably, I cannot share the input samples for copyright reasons.

Valid output can only be produced after restarting ffmpeg after the error occurs, exactly 26.5 hours later.

[Balling]

Duplicate of #8689 and #7449.