[ubuntu-mythtv] [SOLVED] Upgrade to 0.25 / recorded program sync problem

[Eric Shubert]

On 06/08/2012 08:07 PM, Eric Shubert wrote:
> On 06/08/2012 05:19 PM, Eric Shubert wrote:
>> I have a bit of a problem with 0.25.
>>
>> I have a BE and 2 FEs which were running 0.24. I upgraded the BE
>> (mythbuntu) and one FE (Lucid w/ mythbuntu repos) to 0.25 and they're
>> running fine.
>>
>> The other FE I (re)built from scratch on Precise. That FE works fine for
>> live TV (using BE), but recorded programs have a problem. When playing
>> recorded programs, the audio lags the video by a couple seconds. This
>> happens on all recordings that were made with 0.24. Since upgrading
>> everything to 0.25, I have 3 programs recorded so far. Two play ok on
>> the problem host, but one plays out of sync like the 0.24 recordings.
>> It's the 2nd of the 3 recordings that plays out of sync.
>>
>> All hosts are up to date with the latest packages from the mythbuntu
>> repos.
>>
>> Anyone have any ideas where to look for a resolution? I'll be glad to
>> post any information which may be helpful.
>>
>> TIA.
>
> I've tried changing various settings, largely to no avail. Something has
> changed since yesterday though (updated pulseaudio-client package
> perhaps?) which has improve things slightly.
>
> I notice now that all 1080i recordings are playing normally. I know for
> certain that this was not the case yesterday. I also notice that all
> recordings which play with the audio sync problem (audio lags 1-2
> seconds, and the amount of lag appears to vary between recordings) are
> show 720p for resolution. On recordings that show nothing for
> resolution, some have the lag and some don't.
>
> So the scenario now appears to be unlrelated to which version made the
> recordings. The differentiating factor appears to go along with the
> broadcast resolution. IOW, when a program is broadcast in 1080i, the
> audio is X and it works, while with 720p broadcasts, the audio is Y
> which has the problem playing back.
>
> I'll try to get some more recordings to see if I can narrow things down
> a bit more. I haven't see this with any live TV programs, but that's not
> to say it can't happen.
>
> Any ideas are appreciated.
>

For posterity. I tried a different tact, which was to install mythbuntu 
first, then enable ubuntu desktop from the mythbuntu control center. 
Audio sync is now flawless.

I think the problem was related to pulse audio. With the new setup, I 
configured with the alsa hdmi device instead of pulse. I did try 
changing the former ubunutu/myth installation to the same hdmi device, 
but I got no audio at all with that. I'm guessing that some of the other 
audio adjustments I made trying to fix the problem caused it to not 
work. I didn't see any point in chasing down that path further since I 
have a working system now.

P.S. FWIW, I'm running this frontend from an 8G USB drive. Booting is a 
little slower than the HDD, and updates take a bit longer (not that 
updates on the HDD were very fast). Normal/typical operation is 
otherwise very nice though. $10 for 2 8G drives (one live, one backup) 
vs $60 or more for a 2.5" HDD. I've opted for the former, and am very 
happy with my decision. There are some tweaks I can make to reduce i/o 
to the USB drive, but it's working nicely even w/out doing that yet.

-- 
-Eric 'shubes'