[pulseaudio-discuss] audio video out of sync

[Laurențiu Nicola]

I can confirm that; with module-rtp-recv, I've seen latencies of tens of
seconds.

Laurentiu Nicola

On Tue, Feb 18, 2014, at 13:08, Thomas Martitz wrote:
> Am 18.02.2014 10:06, schrieb Tanu Kaskinen:
> > On Tue, 2014-02-18 at 11:04 +0200, Tanu Kaskinen wrote:
> >> On Tue, 2014-02-18 at 04:51 +0100, Malte Gell wrote:
> >>> Am 16.02.2014 12:24, schrieb Tanu Kaskinen:
> >>>
> >>>> On the topic of audio/video sync, synchronization requires accurate
> >>>> latency information. PulseAudio doesn't have that information. If the
> >>>> audio lags by a constant amount all the time, then you can work around
> >>>> the problem by configuring the latency offset with e.g. pavucontrol.
> >>> Thanks for the explanation.
> >>>
> >>> The audio lags do not occur all the time, they occur after some time,
> >>> often audio totally quits, when waiting a while audio comes back again.
> >>>
> >>> /var/log/messages gets flooded with these errors:
> >>>
> >>> [bluetooth] module-bluetooth-device.c: Skipping 412706 us (= 72800
> >>> bytes) in audio stream
> >>> [bluetooth] module-bluetooth-device.c: Skipping 465700 us (= 82148
> >>> bytes) in audio stream
> >>> [bluetooth] module-bluetooth-device.c: Skipping 154683 us (= 27284
> >>> bytes) in audio stream
> >>> [bluetooth] module-bluetooth-device.c: Skipping 126688 us (= 22344
> >>> bytes) in audio stream
> >>> [bluetooth] module-bluetooth-device.c: Skipping 70714 us (= 12472 bytes)
> >>> in audio stream
> >>>
> >>> Do these message give a hint where the problems come from?
> >> The messages indicate that the kernel is accepting audio from PulseAudio
> >> slower than what is required for smooth playback. I would guess that the
> >> problem is interference in the radio signal that prevents reliable
> >> communication.
> > I forgot to mention - these messages do not give any hints about why the
> > latency is increasing, that is, which buffer is getting bigger.
> >
> 
> 
> Doesn't this also appear for network streams, where each network-induced 
> skip adds to the stream latency without any kind of recovery. I.e. PA 
> never decreases the buffers again so that it can easily reach a couple 
> of seconds?
> 
> Best regards
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