[mythtvnz] Audio sync issued with DVBS, mythbunut 12.04 and mythtv 0.25

[Stephen Worthington]

On Mon, 18 Jun 2012 20:53:44 +1200 (NZST), you wrote:

>
>On Sun, June 17, 2012 7:15 pm, Steven Ellis wrote:
>> Hi Guys
>>
>> Ran an upgrade over the weekend and I noticed that David had the same
>> issue over on the MythTV Users list.
>>
>> Basically if I ffwd or jump within a DVB-S recording, in particular a TVNZ
>> stream, audio sync is lost unless I exit playback and re-open the file.
>>
>> He's already raised a ticket for the issue
>> http://code.mythtv.org/trac/ticket/10797
>>
>> Anyone else here seeing wit with DVB-S material
>>
>> I'm currently running 2:0.25.0+fixes.20120614
>>
>> Tried the usual obvious stuff. Any other ideas?
>
>Looks like I've got a fix and updated the ticket with the details. Argh
>Alsa buffers.

I thought I remembered something about ALSA buffer problems with 0.24.
A search of my /etc files turned up this in my rc.local:

# Fix for getting these errors in mythfrontend.log:
#   ALSA, Error: Setting hardware audio buffer size to 6016
#   ALSA, Error: Error opening /proc/asound/card0/pcm0p/sub0/prealloc:
Permission denied.
#   ALSA, Error: Try to manually increase audio buffer with: echo 6016
| sudo tee /proc/asound/card0/pcm0p/sub0/prealloc
#   ALSA, Error: Unable to sufficiently increase ALSA hardware buffer
size - underruns are likely
#   ALSA, Error: WriteAudio: buffer underrun
chmod a+rwx /proc/asound/card0/pcm0p/sub0/prealloc
chgrp audio /proc/asound/card0/pcm0p/sub0/prealloc

With that fix in place, I did a 

  cat /proc/asound/card0/pcm0p/sub0/prealloc

and got a value of 4096.

What sort of default value does Mythbuntu 12.04 have for this?  Would
the same fix help?