[mythtv] AVSync in master, Normal decoding, vga monitor and built-in audio analog stereo

John Pilkington johnpilk222 at gmail.com
Mon Dec 9 22:20:10 UTC 2019

On 09/12/2019 21:20, Gregorio Gervasio Jr. wrote:
>>>>>> John Pilkington writes:
>> Hi Mark, Peter, Tim et al...
>> I'm now running b5edda1b06e, today's master, under el7 with hardware
>> as in the subject.
>> A recording that allows good sensory evaluation of a/v sync shows
>> noticeable drift that is not evident from the -v playback log.
> [...]
>          At least for me, it seems like the sync problems (where audio
> runs ahead of video) are only happening with 1080i (MPEG-2) content and
> only when I use the double-rate software deinterlacers.  If I disable
> double-rate deinterlacing or if I enable "Prefer OpenGL deinterlacers",
> I don't see the problem.  I'll need to dig deeper into it to be sure,
> though ...

Thanks for that suggestion.  I have increased the AVSync2 increment to 4 
ms and selected the low quality deinterlace options, and the drift does 
seem to have gone away.

I had gone to the 1 ms correction setting because the reported timing 
StdDEv seems to track this value.  Perhaps the lower setting prevents 
tracking of the actual sync.  There are still reports of frame dropping, 
and the deinterlacer might not be good enough...


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