[pulseaudio-discuss] Virtual source (microphone)

[Lennart Poettering]

On Mon, 18.01.10 16:36, Grzegorz Kryza (gkryza at gmail.com) wrote:

> > > This can be done using 'module-pipe-source' but it was recently removed
> > > from Fedora packages so I'm looking for alternative.
> > 
> > This won't work, since that device does not really provide any kind of
> > timing control, and also also depends on apps on the other side
> > read/write data in the right speed. It's mostly a toy.
> 
> Yes, but if a timing is done by a process on other side of a pipe?
> We have already implemented a solution based on pipe sink/source which
> takes care about providing a data in correct sample rate, format, etc.
> It works well on all Linux distros with PA we tested except Fedora
> 12.

If you do that you need to make sure you provide an interface for the
PA server to query the latency synchronously with the data
transferred. Note that most video players schedule frames based on the
audio clock, so if the latency estimation is not smooth and dependable
video playback will be jumpy.

module-pipe-sink/-source do not provide that.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
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