[mythtv-users] Audio starts before video on some recordings

[Jesse Hughes]

On 07/24/2014 10:28 PM, Jean-Yves Avenard wrote:
> On 25 July 2014 14:16, Jesse Hughes <jesse at phiwumbda.org> wrote:
>> Hello.
>>
>> I have two HD-PVRs and I'm having an odd effect with recordings from one of
>> the two.
>>
>> On some, but not all, recordings, I hear the audio begin about half a second
>> or more before the video.  The video often starts in a kind of slow motion
>> when this happens.  As a result, the audio is far ahead of the video during
>> playback.
>>
>> This occurs in both HD and SD recordings.  However, and this is the kicker,
>> the problem is not in the recording itself!  If I play back the recording
>> using mplayer, the audio and video are synced.
> What video profile are you using?

Pardon my ignorance, but how do I determine that?  Is that the same as 
"Recording profile"?  Or "Video Playback Profile"?

If the latter, then I've tried High Quality, Normal and OpenGL High 
Quality, with no differences.
>
> if software decoding, this is likely related to how FFmpeg h264
> decoder works when multi-threaded decoding is enabled.
>
> It will only start to output frames once all threads have decoded a
> frame, and with the HD-PVR having rather large spaced reference frame,
> this can take a short while...
>
> Shouldn't lead to bad A/V sync however.
> Which version of mythtv are you using?
>
> if 0.27, try the devel/027candidates as it contains some changes on
> the matter (A/V Sync
> or Master which has much better handling of HD-PVR files, including
> much faster seeking
> _______________________________________________
>
I'm using the stock mythtv from Ubuntu, which appears to be 0.27 
"+fixes".  I'd prefer to stick with versions available through the 
package manager, if I can, since that makes upgrading rather easier.  
Are these development alternatives available as .deb or .apt packages?  
Where would I find them?

Thanks for your help.  It's been a while since I've messed with 
development candidates for any of the software I use.