pulseaudio and adder stream latency

[lsmithso at hare.demon.co.uk]

Can you give me some idea how I might debug this? What should I look
for in the debug output?


Stefan Sauer writes:
 > On 02/02/2014 05:42 PM, lsmithso at hare.demon.co.uk wrote:
 > > Hi: I'm using gstreamer 0.10.  liveadder made no difference at all. I
 > >  tried all kinds of combinations of the clock-source, do-timestamp and
 > >  latency properties , but it made no difference.  I don't really
 > >  understand the clocking stuff, so this wasn't very scientific.
 > The interesting properties are "provide-clock" and "slave-method". To
 > debug this one would need to figure which elements (sink, src1, src2)
 > provides the clock and why the others don't sync to that properly.
 > 
 > >
 > >
 > > I also tried mixing both streams on to themselves. It wasn't perfectly
 > > in sync, butt it wasn't bad, and it certainly didn't drift by
 > > seconds.
 > >
 > > I tried swapping devices around, but I got the following error.
 > >
 > > ERROR: from element /GstPipeline:pipeline0/GstAudioConvert:audioconvert0: not negotiated
 > > Additional debug info:
 > > gstbasetransform.c(2525): gst_base_transform_handle_buffer (): /GstPipeline:pipeline0/GstAudioConvert:audioconvert0:
 > > not negotiated
 > Ideally you use a "audioconvert ! audio/x-raw, ..." after both sources
 > to ensure you have the same format. adder does not convert.
 > 
 > Stefan
 > >
 > > Is there a clue there. Recording works if the  1st element device is
 > > the output monitor, and the second is the mic. The above error happens
 > > when the 1st element is the mic and the 2nd the  output monitor.
 > >
 > > Stefan Sauer 
 > >  > On 01/31/2014 09:49 AM, lsmithso at hare.demon.co.uk wrote:
 > >  > >
 > >  > > Hi:
 > >  > >
 > >  > > I'm trying to record headphone output and mic input  simultaneously to
 > >  > > a single file, using pulseaudio streams and the adder plugin.
 > >  > >
 > >  > > The problem is that the recording of the sink rapidly lags behind the
 > >  > > source, eventually by several seconds. The result is that the
 > >  > > headphone and mic recording are completely out of sync.
 > >  > >
 > >  > > Any idea of what causes this and how to fix it? Here's the pipeline:
 > >  > >  
 > >  > >
 > >  > >
 > >  > > gst-launch -q -e pulsesrc device=2 ! adder name=mix ! audioconvert ! vorbisenc ! oggmux  ! filesink location=r.ogg pulsesrc device=3 ! mix.
 > >  > >
 > >  > >
 > >  > Hi,
 > >  > is this with gst-0.10 or 1.X? Btw. it is not latency that your are
 > >  > seeing, sounds more like clock drift perhaps. I wonder which of both
 > >  > sources is providing the clock. Can you swap device=2/3 and retry?
 > >  > 
 > >  > Stefan
 > >  > _______________________________________________
 > >  > gstreamer-devel mailing list
 > >  > gstreamer-devel at lists.freedesktop.org
 > >  > http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
 > >
 > 
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-- 
Les Smithson