[pulseaudio-discuss] Dynamically loading/unloading sinks or sources

Ng Oon-Ee ngoonee at gmail.com
Thu Nov 6 23:36:27 PST 2008

Hi all,

I'm using Pulseaudio with Ubuntu Intrepid Ibex (0.9.10 version). I've 
been going about converting my laptop to a recording machine, starting 
with the installation of JACK, of course. My current setup has JACK 
directly accessing my sound card, with Pulseaudio loading the modules 
'module-jack-sink' and 'module-jack-source'. However, this means that 
when I stop JACK, some programs currently outputting sound to Pulseaudio 
(Rhythmbox, for example) hang and have to be killed manually. This also 
means that, without killing and restarting Pulseaudio, I cannot shut 
JACK down and have Pulseaudio automatically 'grab' the sound card. 
Neither can I, when running Pulseaudio without JACK, inform Pulseaudio 
to release its grab on the sound card so that JACK can grab the sound 
card (except with pasuspender, which isn't useful when what I actually 
want to do is have Pulse play THROUGH JACK).

Sorry about the long background. Here's the questions I have:-

1. Is there a way to instruct 'module-alsa-sink' and 
'module-alsa-source' to release their hold on the sound card? To maybe 
further complicate matters, I'm loading those modules through 
'module-hal-detect'. I'd rather not unload the modules, because I've had 
problems loading them again once they've already been loaded to a 
running server.

2. Currently, upon starting JACK I run a script which loads the two 
modules 'module-jack-sink' and 'module-jack-source'. When I want to quit 
JACK without crashing Pulseaudio, I have to disconnect the connections 
JACK has made to Pulse, then quite JACK. This unloads 'module-jack-sink' 
and 'module-jack-source' automatically, leaving pulse without sinks or 
sources. Is there any way to use pactl to inform Pulse to reacquire the 
ALSA sinks and sources?


Ng Oon-Ee

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