[mythtv-commits] Ticket #8792: DVD playback issues with 5.1 AC3 sound

MythTV mythtv at cvs.mythtv.org
Wed Aug 18 23:48:44 UTC 2010

#8792: DVD playback issues with 5.1 AC3 sound
 Reporter:  mythtv@…                 |           Owner:  jyavenard 
     Type:  defect                   |          Status:  assigned  
 Priority:  minor                    |       Milestone:  unknown   
Component:  MythTV - Video Playback  |         Version:  Trunk Head
 Severity:  medium                   |      Resolution:            
 Keywords:  dvd 5.1 audio            |   Ticket locked:  0         

Comment (by mythtv@…):

 The logs are slightly confusing as the DVD source runs through a number of
 title changes (which are mostly empty) before hitting the studio intro
 (which is where the problem occurs).

 In both cases the last audio stream selected was English AC3 7ch.
 However, the audio code then opens the non-passthru device and tries to
 output 2ch audio.  This works ok when the frontend is configured for
 stereo, but not when configured for 5.1  Oddly, in both cases - the audio
 is sent as PCM rather than an AC3 stream.

 The problem in the 5.1 playback seems to be here:

 2010-08-18 21:22:07.924 Player(0): Waiting for video buffers...
 2010-08-18 21:22:07.924 AO: Pause 1
 2010-08-18 21:22:07.929 AO: OutputAudioLoop: audio paused

 Where the audio gets paused and never restarted.

 To me it feels like and AV sync issue.  It certainly seems to have been
 made worse by the recent dvdnav resync, but I was having intermittent
 problems with slowed audio playback before this (but only with DVDs).

 I might try pulling out the relevent VOB file from the DVD and try playing
 that back on it's own.

 As the 48k override, I've got a slightly broken Alsa driver which claims
 to support a range of sample rates, but if you actually use anything other
 than 48k, then the driver gets into  a state where no audio output works
 until it is reloaded.

Ticket URL: <http://svn.mythtv.org/trac/ticket/8792#comment:3>
MythTV <http://www.mythtv.org/>

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