[mythtv-users] HD-PVR Audio Sync Issues After Channel Change

[Alan Young]

On 04/12/2010 03:13 PM, John P Poet wrote:
> On Mon, Apr 12, 2010 at 3:40 PM, John Boyle<general_veers_01 at yahoo.ca>  wrote:
>> My HD-PVR pretty much works wonderfully until I change the channel, at which point the audio goes way out of sync. I'm running latest svn and have tried various versions of the firmware to no avail.
>>
>> I'm changing channel via firewire on an SA3250 using sa4250_ch - I couldn't get the 3250 to work properly. There's no significant errors on front or backend, so I'm not entirely sure where to look.
>>
>> Could it be an issue with the channel change script (I don't see how) or is there something else that could be the culprit.
>>
>> Thanks!
>
> The HD-PVR doesn't like being told to "record" when the STB (e.g.
> SA3250) has not stabilized on the new channel yet.  The result is
> usually a few seconds of corruption, which could easily cause you A/V
> sync issue.
>
> Easiest fix, is to add a few seconds of sleep to the end of your
> channel change script.  You could also try the patches listed on the
> wiki.

I've seen it happen.  And I have a channel change delay in my script.  I'm 
using a USB changer with a DirecTV box.  I think it's some kind of playback 
sync as pausing the playback and then restarting again after a second seems to 
help fix it.  Sometimes I have to do that twice.  When I do that the video 
"warps" to try to get back into sync.  Backing up and restarting seems to fix 
it too.

Alan