GNOME Bugzilla – Bug 678148
[tsdemux] missing timestamp on DVB subtitles
Last modified: 2013-06-12 13:27:30 UTC
Code from 0.10 GIT: gstreamer 11c8ffb6fbd20081c49708cb41e0ec6e2ed09c27 -base 1f6056eafb6c37f4c78ed22b2796a1dcaeb51ee6 -good 50c85392cd0a8824b917790a12d92f237dbd55ce -bad acf4463f2b9bf7a7cdbac288e50dfb41626fc8b2 -ugly 09284b9862504f73924d88ac00b2c7d08dd7a001 -ffmpeg 9761a6501b518a554fc5e52de8e9acdc4f8ced9a Plus a patch to -ugly mpeg2dec to set its rank to NONE making -ffmpeg MPEG2 decoder used. How long before they disappear seems to be "random". I got lucky and captured a test stream where it happens a minute or two into play which I can share on request (it is still quite big).
On the one hand, this could have to do with (or identical to) bug #666674 ? On the other hand, sample is useful to have a further look ...
Looks like the problem is in tsdemux in that it can produce subtitle buffers without timestamp, and that seems due to gst_ts_demux_record_pts(), which misdetects the gaps in a subtitle stream as "reverse rollover" in the timestamp (and things go wrong from there). Not immediately sure what to do about that, since this rollover stuff is tricky stuff, and it is not clear to begin with what is currently being done there (e.g. some rollover detection both in gst_ts_demux_record_pts() but also in mpegts_packetizer_pts_to_ts()) (see also e.g. bug #674536).
For the record this is still broken with 0.10 GIT from 08.08.2012. Version details as follows: gstreamer-0.10.36.1-git120808.955693fc36ac38dc604e1e616e1c441cc3c25e1c -ffmpeg-0.10.13.1-git120808.1db8779252afa264996e59c18430f70cc5582b28 -base-0.10.36.1-git120808.12ef907f8a3762685da0b96391edc30a78d31805 -bad-0.10.23.1-git120808.e3b09c25b16c42ca7a83472c61054f34a31f572c -ugly-0.10.19.1-git120808.afeffcdb44135c04c5767bba8b10fab82ec9a9df -good-0.10.31.1-git120808.c1f1b62ca26106fba30fca65b0945c31da0ffe22
Tvrtko, is this still an issue with 1.x ?
Tested with file provided by Tvrtko, works fine now. Most likely due to fixes from 1/2 months ago.