random buffering issues
#1
I'm using VNSI Server on several platforms and experiencing the same kind of problem for a while now. Every now and then the playback of live tv channels will stutter for a short time before its stable again. There is no obvious pattern, it can happen once in an hour or even every few minutes on every kind of channel (HD/SD). Most often its less than a second of buffering when theres just no audio. Sometimes it takes a while until everything is sync and stable again though. This is what the log says when the problem occurs:

Code:
04:05:40 T:140677828572928 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
04:07:54 T:140677828572928 WARNING: Previous line repeats 499 times.
04:07:54 T:140677828572928   DEBUG: CSoftAEStream::Flush
04:07:54 T:140677954397952   DEBUG: audio stream stalled. start buffering
04:07:54 T:140677954397952   DEBUG: CDVDPlayer::SetCaching - caching state 2
04:07:54 T:140679704303360   DEBUG: CSoftAE::Run - Sink restart flagged
04:07:54 T:140679704303360    INFO: CSoftAE::InternalOpenSink - keeping old sink with : AE_FMT_FLOAT, FL,FR, 48000hz
04:07:54 T:140679704303360   DEBUG: CSoftAE::InternalOpenSink - Using speaker layout: 2.0
04:07:54 T:140679704303360   DEBUG: CSoftAE::InternalOpenSink - Internal Buffer Size: 4096
04:07:54 T:140677954397952   DEBUG: CDVDPlayer::HandleMessages - player started 1
04:07:54 T:140677954397952   DEBUG: CDVDPlayer::HandleMessages - player started 2
04:07:54 T:140677954397952   DEBUG: set caching from pvr to done. audio (1) = 11. video (1) = 25
04:07:54 T:140677954397952   DEBUG: CDVDPlayer::SetCaching - caching state 0
04:07:54 T:140679704303360   DEBUG: CSoftAE::Run - Sink restart flagged
04:07:54 T:140679704303360    INFO: CSoftAE::InternalOpenSink - keeping old sink with : AE_FMT_FLOAT, FL,FR, 48000hz
04:07:54 T:140679704303360   DEBUG: CSoftAE::InternalOpenSink - Using speaker layout: 2.0
04:07:54 T:140679704303360   DEBUG: CSoftAE::InternalOpenSink - Internal Buffer Size: 4096
04:07:54 T:140677828572928   DEBUG: CDVDPlayerAudio:: Discontinuity1 - was:17932174316.187668, should be:17932646935.753334, error:472619.565666
04:07:55 T:140677828572928 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available
04:08:00 T:140677934884608 WARNING: Previous line repeats 12 times.
04:08:00 T:140677934884608   DEBUG: CPullupCorrection: detected pattern of length 1: 40000.00, frameduration: 40000.000000
04:08:00 T:140677828572928 WARNING: CDVDMessageQueue(audio)::Get - asked for new data packet, with nothing available

The server runs Ubuntu 12.04 with VDR 1.7.22 and latest vdr-plugin-vnsiserver. The clients are an ION based device running OpenElec RC 2, an Intel HD4000 based device with OpenElec RC 2 and the server itself running XBMC Frodo stable release. I noticed that the buffering/stuttering will only appear during livetv mode while recordings of exactly the same content will play fine through pvr recording mode.
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#2
Can you make sure you have set "sync playback to display" with video clock as master and audio drop/dupe. Please post a full debug log with those settings.
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#3
Thanks for the respond! Yes I have set the sync playback to display using the suggested settings.
Heres my debug log:

http://xbmclogs.com/show.php?id=32787
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#4
This issue is not caused by vnsi but audio. Audio sucks out the queue, finally it stalls, and tries to re-fill the buffers. The point with real-time streams is that the buffers can't be filled during normal playback. There's exactly the same number of packets coming in as going out. Can you try to increase cache level for audio in advanced settings:

You need to create a pvr section it not aleary available. Then add minaudiocachelevel, which defaults to 10

<pvr>
<minaudiocachelevel>20</minaudiocachelevel>
</pvr>
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#5
I added minaudiocachelevel to my advancedsettings.xml and so far it feels like an improvement at least. The issues still appear but not as often as it used to. Maybe increasing the value will make it work perfectly so I'll try some higher values. I'm just wondering if everyone using livetv has to change this setting or if it depends on the (audio) hardware.
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#6
I don't see those issues on my systems but I am aware those and I am almost sure that it's an issue of the audio engine. On commercial breaks audio config changes from e.g. from 5.1 to stereo. This requires audio engine to reconfigure. If the buffers are not drained properly, you'll lose packets which sucks out the queue.
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#7
btw: I have purged pulse audio from all of my systems.
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