[LAU] Testing JACK and PA latency

[Fons Adriaensen]

On Sat, Sep 21, 2013 at 04:07:32AM +1000, Patrick Shirkey wrote:
 
> I can hear the signal fine but I cannot hear or see the result of the
> signal after it comes back in the mic input. I could attempt to capture
> that part of the signal too for reference sake.
> 
> If there are significant dropouts will that be the likely cause of the "??"

Depends on what you mean by 'dropouts' :-)
 
> I'm running jack with realtime capabilities but not a realtime kernel.

That should be fine. I haven't used a RT-patched kernel for years.

The loop via system:playback -> cable -> system:capture is only
there to give you the real round-trip latency, it doesn't have
any importance for examining this problem. You could just send
the signal from PA-sink directly to jack_delay.

Try to record the signal coming back from the PA-sink, e.g. using
timemachine. I'm pretty sure there will be discontinuities in the
recorded waveform.

Ciao,

-- 
FA

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