[mythtv] RE:DVB Audio Sync Issues

Edward Wildgoose Edward.Wildgoose at FRMHedge.com
Mon Sep 1 11:40:07 EDT 2003


I do get out of sync audio on certain channels such as ITV2, but not on a regular basis.  I more commonly get what another user described which is audio which slowly drifts out of sync over about half an hour or so, and doesn't seem to get reset (unless perhaps you pause, rewind, etc).
 
However, in your case if you are getting more than a little of this corruption reported below, then I would think that it is likely to be part of the problem.  Try using tzap and pipe the /dev/dvb/adaptor0/dvr0 stream into mplayer and see if you get the same problem (or dvdstream)
 
There are some issues being discussed on the DVB list about corruption due to PCI busting issues, if you are getting lots of really bad breakup and mpeg artifacts then this might also be relevant to you (if it isn't severe though then probably not)

Ed

-----Original Message-----
From: Linda Crawford [mailto:ljcrawford at totalise.co.uk]
Sent: 01 September 2003 08:49
To: mythtv-dev at mythtv.org
Subject: [mythtv] RE:DVB Audio Sync Issues


Thanks for the earlier help Kenneth,
 
I haven't managed to get dvbstream to work yet, the latest version is looking for sec.h and that isn't in the kernel or LinuxTV drivers?
 
Mainly, the DVB-T audio video/sync problem seems to be that:
 
1. Channel 5 (a QAM64 channel FEC 1/2) channel seems to resync. I get a silence period every so often (4-5 minutes) and the audio resyncs. Seems watchable apart from the odd 1/2 a second silence where the audio resyncs.
 
2. BBC (QAM16 FEC 3_4) channels always go out of sync (audio always runs behind the picture). On the console I see (not sure if it all correct as I'm not sure I got it all when I copied it):
 
 
Changing from None to WatchingLiveTV
2003-08-31 21:17:05 Delaying to next trigger: 332046
2003-08-31 21:17:05 Delaying to next trigger: 284317
2003-08-31 21:17:05 Delaying to next trigger: 224218
ac-tex damaged at 0 33
mb incr damaged
ac-tex damaged at 10 17
ac-tex damaged at 0 16
ac-tex damaged at 27 17
ac-tex damaged at 8 19
ac-tex damaged at 14 19
ac-tex damaged at 1 20
ac-tex damaged at 4 21
ac-tex damaged at 43 23
invalid mb type in P Frame at 10 23
invalid mb type in P Frame at 23 24
ac-tex damaged at 39 25
invalid cbp at 38 27
ac-tex damaged at 21 27
ac-tex damaged at 16 28
ac-tex damaged at 0 31
mb incr damaged
ac-tex damaged at 12 31
invalid cbp at 38 32
ac-tex damaged at 4 33
ac-tex damaged at 10 35
mb incr damaged
concealing errors
Warning MVs not available
slice missmatch
ac-tex damaged at 1 16
invalid mb type in B Frame at 4 17
slice missmatch
slice missmatch
slice missmatch
invalid mb type in B Frame at 1 21
ac-tex damaged at 12 22
mb incr damaged
invalid cbp at 5 24

Any help would be great!
 
Thanks,
 
Ian


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