[mythtv-users] Video is behind audio, dropping frames to catch up (VDPAU, HD content)

[Paul Gardiner]

On 28/02/2013 12:01, Mike Perkins wrote:
> On 28/02/13 08:23, Paul Gardiner wrote:
>> On 27/02/2013 22:04, Thomas Börkel wrote:
>>> HI!
>>>
>>> I have now tried many things, but I am running out of ideas.
>>>
>>> * it happens usually every 2-10 minutes
>>> * it happens for HD h264 and SD MPEG2, just for HD a little more often
>>> * it happens with and without VDPAU
>>> * it happened on old and upgraded hardware (only sound card identical)
>>> * it happens on 0.26 and earlier versions
>>> * I have tried all VDPAU profiles
>>> * I have disabled logging over NFS (> /dev/null)
>>> * I have enabled realtime prio (but it is not mentioned in the log)
>>> * I have reniced mythfrontend to -2 and X to -12
>>> * I have set the GPU to max. frequency all the time, so no switching
>>> * I have disabled the often crashing mythlcdserver
>>> * I have tried different kernel and NVidia driver versions
>>>
>>> What else can I try? What more info should I provide?
>>>
>>> Probably, something needs a little CPU time every now and then and this
>>> probably causes that little "jump" in playback and the log entry from
>>> the subject, but I don't know what it is and why MythTV is so sensitive
>>> on such hardware specs (Core i3, 3.1 GHz)?
>>>
>>> Or does it probably have something to do with the fact that this is a
>>> diskless PXE frontend?
>>>
>>> Any hints would be greatly appreciated.
>>
>> None of the myth systems I've built have ever synchronized AV correctly.
>> I've always had to pause and unpause every now and then to regain sync
>> and even then it's to get it to a consitentish 100ms which I then
>> correct within my AV receiver. It's odd, because every other player I've
>> tried with my recordings or downloads show them correctly in sync.
>>
> My diskless PXE frontend has never had problems with AV sync. I use NFS
> to mount the root but not for media directories. On the other hand, my
> sound comes out the TV. Perhaps it is the "AV receiver" which is the
> common variable?

I have wondered that. I will test, although several of the myth systems
I was referring to were connected direct to speakers, and the sync was
always variable and depended on the last user command. I think my
current frontend may be pretty much ok when I'm not using different
screen modes for different video resolutions, but I'm not sure of that.
Need to do more testing.

What CPU are you running?

P.