[mythtv-users] "Failed to initialise A/V sync" on playback for some MKVs

[Kingsley Turner]

On 15/10/15 06:34, Kingsley Turner wrote:
> Hi-ya,
>
> Just upgraded my FE/BE box, mythtv 0.27, from Mythbuntu installer disk 
> 14.04.02.
>
> There's still a few minor problems to be worked out, but one curious 
> problem arises playing back a particular set of MKVs.
>
> The FE sits there with it's "Please Wait..." screen, and sometimes there's 
> a 1-2 second burst of audio.
> But then it drops back to the menu with a popup error message: "Failed to 
> initialise A/V sync".


I've fixed this somewhat - the video plays now, but sound plays OK for a 
second, then pauses, then the next bit etc.
This corrresponds with the log:

Oct 15 14:49:31 mediabox mythfrontend.real: mythfrontend[1506]: I 
CoreContext mythrender_vdpau.cpp:597 (CheckOutputSurfaces) VDPAU: Added 2 
output surfaces (total 4, max 4)
Oct 15 14:49:32 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
104ms for video buffers Afffffffffffffffffffffffffff
Oct 15 14:49:32 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
208ms for video buffers Afffffffffffffffffffffffffff
Oct 15 14:49:32 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
312ms for video buffers Afffffffffffffffffffffffffff
Oct 15 14:49:32 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
415ms for video buffers Afffffffffffffffffffffffffff
Oct 15 14:49:32 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2145 (PrebufferEnoughFrames) Player(4): Timed out 
waiting for frames, and#012#011#011#011there are not enough free frames. 
Discarding buffered frames.
Oct 15 14:49:34 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
104ms for video buffers fffffffffffffffffffffffffffA
Oct 15 14:49:34 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
208ms for video buffers fffffffffffffffffffffffffffA
Oct 15 14:49:34 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
313ms for video buffers fffffffffffffffffffffffffffA
Oct 15 14:49:34 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
418ms for video buffers fffffffffffffffffffffffffffA
Oct 15 14:49:34 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2145 (PrebufferEnoughFrames) Player(4): Timed out 
waiting for frames, and#012#011#011#011there are not enough free frames. 
Discarding buffered frames.
Oct 15 14:49:35 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
103ms for video buffers ffffffffffffffffffffffffffAf
Oct 15 14:49:35 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
207ms for video buffers ffffffffffffffffffffffffffAf
Oct 15 14:49:35 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
311ms for video buffers ffffffffffffffffffffffffffAf
Oct 15 14:49:36 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
414ms for video buffers ffffffffffffffffffffffffffAf
Oct 15 14:49:36 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2145 (PrebufferEnoughFrames) Player(4): Timed out 
waiting for frames, and#012#011#011#011there are not enough free frames. 
Discarding buffered frames.
Oct 15 14:49:37 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
104ms for video buffers fffffffffffffffffffffffffAff
Oct 15 14:49:37 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
207ms for video buffers fffffffffffffffffffffffffAff
Oct 15 14:49:37 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
311ms for video buffers fffffffffffffffffffffffffAff
Oct 15 14:49:37 mediabox mythfrontend.real: mythfrontend[1506]: N 
CoreContext mythplayer.cpp:2130 (PrebufferEnoughFrames) Player(4): Waited 
415ms for video buffers fffffffffffffffffffffffffAff

etc. etc.

I played around with the VDPAU rules - upped the number of CPUs from 1 -> 4, 
and turned on High Quality 2x deinterlacing.
Set the "> [0] [0]" to ">= [0] [0]" rule for using VDPAU for playback.

I added TripleBuffer=True and Composite=Disable to xorg.conf.

Still, it's only certain videos it having trouble with.

My bluray rips playback flawlessly - so it's not CPU or IO bound or anything.
(I don't get it)

It's driving me a bit mental, because the real reason I upgraded was 
playback with SSA-type subtitles was jerky.


-kt