[pulseaudio-discuss] Question about writable data

[Tanu Kaskinen]

On Thu, 2015-12-31 at 19:39 +0200, Alexandros Chronopoulos wrote:
> Source and sinks that share the same clock source are those found in the
> same sound card, right?

I don't know how sound cards are usually designed, but I would guess
that yes, the audio pipelines on the same sound card probably share the
clock.

> Which are the options if this is not the case, if
> for example I use a USB mic with my system speakers? Is there any way to
> prevent the process from clock driff?

You can't just make the problem go away. Either you accept that there
will be occasional glitches, or you manipulate the audio data so that
it plays back a bit faster or slower than it would normally do.
PulseAudio has module-loopback, which can be used to connect a source
to a sink, and module-loopback adapts to the clock drift by converting
the audio data to slightly different sample rate. I don't know what
your application does, but if it doesn't do anything else than move
audio from a source to a sink, you can replace your application with
module-loopback.

-- 
Tanu