[mythtv-users] HD-PVR audio sync issues

Jim Morton Jim at Morton.hrcoxmail.com
Mon Jan 17 21:55:46 UTC 2011

On 1/17/2011 4:20 PM, mythtv at blandford.net wrote:
> Hello,
> I recently made the transition from cable to dish network.
> I am running Fedora 14 with mythtv from rpmfusion 0.24-2.fc14.x86_64 
> packages.
> My backend has two HD-PVRs connecting to dishnetwork vip 211k 
> receivers using SPDIF.
> I am having bad audio sync issues.  I see it in two cases.
> 1) When changing channels the audio is off by about 2 seconds.  This 
> can some times be fixed by changing to a different channel and back, 
> but not always.
> 2) Watching a show for 30 minutes will result in 2-3 second audio lag 
> by the end of the show.  Exiting and coming back into the channel 
> fixes the issue.
> I see lots of posts from people who are using the HD-PVR, so I am 
> guessing I am missing some simple setup peice.
> Any suggestions on how to eliminate the audio lag issues?
I have a similar setup since August 2010 except audio is over the 
composite cables. My BE was set to run 2 jobs and begin commercial 
detection when it began recording. I was have progressive audio drift 
throughout some shows and by the end of the show it was off by as much 
as 5 seconds. Often the recording would just quit about 46 minutes into 
an hour show.
Setting the BE to 1 job at a time and to wait until the recording is 
complete before beginning commercial detection is what fixed it. At the 
time I did not believe that was going to make a difference but after a 
couple of months of no recurrence I am a believer.
Your description of the problem is slightly different so I'm not sure 
you have the same issue I did but just to test I suggest you try 
reducing the job load and see if that makes a difference.


  Jim Morton

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