Ticket #5978 (closed defect: fixed)
Opened 3 years ago
Last modified 3 years ago
frame drop causes dvb subtitles to disappear
| Reported by: | jheikkal@… | Owned by: | danielk |
|---|---|---|---|
| Priority: | trivial | Milestone: | 0.22 |
| Component: | Video Playback | Version: | head |
| Severity: | low | Keywords: | |
| Cc: | Ticket locked: | no |
Description
Hi, Noticed this defect recently... When watching channel/recording with dvb teletext on and frames are being dropped, subtitles disappear. When skipping backwards a bit, video is synced and subtitles are shown again for a while until frame drop. Don't know the cause of dropping because it's been working fine until now and dropping isn't even noticable. This happens with xv and xvmc. But I don't think frame drops should break subtitle rendering?
Attachments
Change History
Changed 3 years ago by jheikkal@…
- Attachment playback.log added
comment:1 Changed 3 years ago by jheikkal
Actually frame dropping isn't causing this. Disabling opengl vsync fixes dropping but still subtitles just disappear with no apparent reason in playback log.
'video_output' mean = '39999.29', std. dev. = '339.99', fps = '25.00' 2008-12-06 19:52:24.865 Clearing expired subtitles from OSD set 'video_output' mean = '39998.93', std. dev. = '129.54', fps = '25.00' 'video_output' mean = '39997.31', std. dev. = '348.05', fps = '25.00
Thats it, no more "setting subtitles visible" log output after that. Only seeking backwards fixes it.
Tried with two different machines with svn 19246. I'm out of ideas...
comment:2 follow-up: ↓ 3 Changed 3 years ago by danielk
- Priority changed from major to trivial
- Status changed from new to infoneeded_new
- Severity changed from medium to low
We will need a short sample of the video that exhibits this problem, ~15 seconds.
comment:4 Changed 3 years ago by jheikkal@…
Because problem appears between 10s to 10min here is one 10min clip. https://juhis.dy.fi/mythtv/DVB-text_sample.mpg Subtitle is finnish.
comment:5 Changed 3 years ago by danielk
- Status changed from infoneeded_new to new
I'm putting this in my queue, but if anyone else wants to grab this ticket and fix this, please feel free.
comment:6 Changed 3 years ago by danielk
- Owner changed from ijr to danielk
- Status changed from new to assigned
comment:7 Changed 3 years ago by otto at kolsi dot fi
I can also reproduce this here with latest trunk. If needed I can try to produce more samples (if the problem remains in cut down version of the file).
comment:8 Changed 3 years ago by danielk
- Status changed from assigned to infoneeded
I can't reproduce the problem with the DVB-text_sample.mpg. Otto if you have a sample that would help, the smaller the better. <30 seconds would be best.
comment:9 Changed 3 years ago by tomimo@…
I have noticed that this problem appears on every single recording that contains the DVB subtitles. It's only a matter of time (anything from a 30s to 10 minutes as somebody mentioned earlier). Interesting thing is that whenever the dvb subtitles disappear, it is enough to rewind 5-10s and start playing again and the subtitles start again. First I thought that it might be related to some problem with timecode (start & stop) values being out of sync or something, but now I noticed that whenever the subtitles disappear, nobody has been calling AddAVSubtitle() for a short while --> the existing decoded dvb subtitles get consumed and after that there is nothing to display anymore.
comment:10 Changed 3 years ago by tomimo@…
It looks like the fix mentioned here https://roundup.ffmpeg.org/roundup/ffmpeg/issue536 really does seems to work ---> checked one full movie with dvb subtitles without problems which hasn't been working for a long time.
comment:11 Changed 3 years ago by danielk
- Status changed from infoneeded to closed
- Resolution set to fixed
Fixed by [19641]. Apply robcam fix for subtitle issue, this has not yet been resolved upstream so I left a note for anyone doing the ffmpeg merge. Thanks to tomino for finding the upstream bug report.
mythfrontend playback log