[gst-devel] Pipeline with live and non-live sources and sinks

[Wim Taymans]

On Tue, 2010-09-14 at 16:41 +0300, Henrik Hedberg wrote:
> On 14.09.2010 13:02, Henrik Hedberg wrote:
> 
> > We have a problem constructing a pipeline with live and non-live sources
> > and sinks. The following pipeline results audible scratches or "jumps"
> > during playback:
> >
> > gst-launch-0.10 filesrc location=/tmp/test.mp3 ! decodebin !
> > audioconvert ! autoaudiosink autoaudiosrc ! audioconvert ! wavenc !
> > filesink location=/tmp/recording.wav
> >
> > It may be buffer under-run or latency issue. It does not happen every
> > time but usually and it occurs especially at the beginning of the
> > stream. The recorded wav is perfect.
> 
>     I have tested the same pipeline with different versions of 
> GStreamer. It seems that 0.10.21 and 0.10.23 were working as expected, 
> but this problem (bug?) appears in 0.10.25 and 0.0.28. Does anybody have 
> an idea, what has been changed between 0.10.23 and 0.10.25 related to 
> this issue?

It's because the sink has to slave its clock to the pipeline clock,
which is the one provided by the source. Usually you get little glitches
when the clocks try to match rates and or when resync happens because
the clocks drift too much.

If you don't need synchronization between the playback and the capture,
you can set slave-method=none on the sink or the source.

Wim

> 
>     BR,
> 
>     Henrik
>