[mythtv-commits] Ticket #7784: WriteAudio: buffer underrun during playback of CD audio

[MythTV]

#7784: WriteAudio: buffer underrun during  playback of CD audio
--------------------------------------------+-------------------------------
 Reporter:  Paul <paul@…>                   |        Owner:  jyavenard 
     Type:  defect                          |       Status:  new       
 Priority:  minor                           |    Milestone:  unknown   
Component:  MythTV - Audio Output           |      Version:  0.22-fixes
 Severity:  medium                          |   Resolution:            
  Mlocked:  0                               |  
--------------------------------------------+-------------------------------

Comment(by psylencer <d.herlihy@…>):

 Stuart,

 Thanks for having a look at this, although I think you've closed the
 ticket prematurly.

 I have fully read and understood and impliemnted changes above.

 I've done some more testing of this problem and reverted back to version
 .22.

 To clarify, (refer to bug #8181) and for the benefit of everyone here, the
 reason I was not receiving buffer underrun messages in mythfrontend log
 was because I was not using ALSA as my audio device, I was using dev/dsp
 (which does not return buffer errors to mythfrontend log).  Changing to
 ALSA revealed the dreaded buffer underrun messages.  While running .22,
 both the LG drive and the Pioneer drive displayed exactly the same 15
 second buffer issues.

 I upgraded to .23 using Mythbuntu Auto Daily Builds and when i did, the
 pioneer drive played back fine and the LG drive continued to display the
 buffer messages.

 Thinking this was something to do with the LG drive, I installed a brand
 new Asus drive which displayed exactly the same problem and error messages
 as did the LG.

 Basically, the 2 year old Pioneer Drive woks fine with the .23 and the
 brand new LG and Asus drives exibit buffer underrun messages.  :

 Here is the log from mythfrontend for the Asus drive (not working) and
 then the Pioneer Drive (Working).

 ASUS BRW-24B1LT-16


 {{{
 2010-03-16 16:20:03.949 CD status has changed.
 2010-03-16 16:20:22.823 AO: Using resampler. From: 44100 to 48000
 2010-03-16 16:20:22.824 Opening audio device 'default'. ch 2(2) sr 48000
 (reenc 0)
 2010-03-16 16:20:22.824 Opening ALSA audio device 'default'.
 2010-03-16 16:20:23.967 AO: Using resampler. From: 44100 to 48000
 2010-03-16 16:20:23.968 Opening audio device 'default'. ch 2(2) sr 48000
 (reenc 0)
 2010-03-16 16:20:23.968 Opening ALSA audio device 'default'.
 2010-03-16 16:20:24.035 MythCDROMLinux::setSpeed() - Limiting CD/DVD Speed
 to 354KB/s
 2010-03-16 16:20:24.044 MythCDROMLinux::setSpeed() - CD/DVD Speed Set
 Successful
 2010-03-16 16:20:24.044 MediaMonitor::setSpeed(%1) - Cannot find/create
 CDROM?/dev/sr0
 2010-03-16 16:20:52.431 WriteAudio: buffer underrun
 2010-03-16 16:20:52.655 WriteAudio: buffer underrun
 2010-03-16 16:21:11.821 WriteAudio: buffer underrun
 2010-03-16 16:21:31.161 WriteAudio: buffer underrun
 }}}

 And this from the Pioneer DVR-215BK(Working).

 {{{
 2010-03-16 16:43:37.237 CD status has changed.
 2010-03-16 16:43:47.539 AO: Using resampler. From: 44100 to 48000
 2010-03-16 16:43:47.540 Opening audio device 'default'. ch 2(2) sr 48000
 (reenc 0)
 2010-03-16 16:43:47.541 Opening ALSA audio device 'default'.
 2010-03-16 16:43:47.598 MythCDROMLinux::setSpeed() - Limiting CD/DVD Speed
 to 354KB/s
 2010-03-16 16:43:47.601 MythCDROMLinux::setSpeed() - CD/DVD Speed Set
 Successful
 2010-03-16 16:43:47.601 MediaMonitor::setSpeed(%1) - Cannot find/create
 CDROM?/dev/sr0
 }}}

 All I did was unplug one and plug in the other.

 Hope this helps

-- 
Ticket URL: <http://svn.mythtv.org/trac/ticket/7784#comment:16>
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