[pulseaudio-discuss] No readable data when connecting stream to input or monitor sources

[Lennart Poettering]

On Tue, 21.04.09 08:16, Erik Botö (erik.boto at gmail.com) wrote:

> Hi,
> 
> I have an ARM-based embedded platform I have developed a pulseaudio
> client for. The client needs to play and record (from line in/mic)
> audio simultaneously in 8 kHz. When I run the application on my
> x86-based dev-system the application works nicely, but when I run on
> target I get no data from the line-in interface. The stream read
> callback is never called and if I try polling to see the amount of
> readable data it says 0 bytes. Unfortunately I can only get pulseaudio
> 0.9.11 and earlier to build in Open Embedded which I use to build my
> target environment (libtool version problem) and on my devsystem I use
> 0.9.14, but I have been careful not to use any API-function that is
> new.

It strongly recommend not to use 0.9.11. Use 0.9.10 (last
pre-glitch-free version) or 0.9.15.

The releases 0.9.11 to 0.9.13 were quite buggy. 

It should be possible to make PA build with a private version of lt
2.2 with minimal configure.ac hackery.

> If I run pulseaudio in an interactive shell and run list-sources I can
> see that module-alsa-source is autoloaded and that my client is
> connected to the source, but the current latency keeps increasing with
> time. After trying to record approx. 10 s the latency will be 10 s.
> The line-in interface works nicely with alsa so alsa supports the chip
> (ak4647) nicely. I have also tried to connect to the monitor stream of
> the sink, but I do not get any data from that source either.

That smells a lot like a driver problem. And it doesn't have to say
much if 'aplay' or a similar application works with that chip, because
PA use a lot more functionality from the audio drivers than 'aplay'
uses and hence will trip over bugs much more likely than 'aplay' does.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
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