[alsa-devel] Capture and playabck together
emmanuel.milou at savoirfairelinux.com
Wed Feb 20 17:09:25 CET 2008
I am developping an open-source C++ softphone based on Alsa. We used to
use Portaudio but we recently decided to switch to Alsa. I am quite
unexperimented in Alsa dev and I got some difficulties to make it work fine.
My capture and playback devices are plughw:0,0. I am using read/write
transfers. When I disable the capture, playback works fine; when I
disable the playback, capture works fine. The problems occurs when I
used them together. If I set hardware parameters for both, the playback
sound is awful and there is no capture, and finally core dumped. If I
set hardware parameters for the playback stream only, the playback works
fine, but no capture, I just get an echo with an input/ouput error.
Where do you think the problem comes from? Isn't it possible to set
hardware configuration for playback and capture? Is there a hardware
ring buffer for each stream ?
Thanks for your help
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