[pulseaudio-discuss] [UCM] usage howto

Soeren Grunewald soeren.grunewald at avionic-design.de
Mon Jan 7 02:46:29 PST 2013

Hi All,

I've been testing pulseaudio-3.0 and now I have some questions. Is there 
any updated documentation available describing the usage of UCM in 
pulsaudio and can the current UCM implementation handle multiple 
soundcards? I plan to use two or three soundcards (all having there own 
UCM configuration) and I'd like to use them with "module-loopback".

During testing I also run into some issues. With my current 
configuration [1], I get a double-free, due missing modifiers. I solved 
this with the attached patch [2]. But then I hit the assertation in file 
src/modules/alsa/alsa-ucm.c function ucm_get_device_property:250

     pa_assert(device->playback_channels || device->capture_channels);

I assume that this is the result of some missing entries in the UCM 
config, but I can't see my issue.


[1] ucm-configs.tar.xz
[2] fix-double-free.patch
Avionic Design GmbH
Soeren Grunewald
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D-22397 Hamburg

Tel.: + 49 40 88187-107
Fax: + 49 40 88187-150
Email: soeren.grunewaldavionic-design.de

Avionic Design GmbH
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