[alsa-devel] [Alsa-devel]JACK will block audio application and audio application will also blcok JACK
Hi experts: I installed JACK and the GUI of it looks good. But it seems it will block the "audio application" and "audio application" will also blcok it. That is to say: 1) If I started the JACK by: sudo /usr/bin/jackd -r -m -dalsa -dhw:0 -r44100 -p1024 -n2 -P Then I open my web brower and try to play a streaming song(play by flash), the song can't play!
2) If I stoped the JACK Then I open my web brower and try to play a streaming song, the song played good!
3)if I play a song by mplayer or web brower at first Then I try to start the JACK, there is an error:
Acquire audio card Audio0 creating alsa driver ... hw:0|-|1024|2|44100|0|0|nomon|swmeter|-|32bit Using ALSA driver HDA-Intel running on card 0 - HDA NVidia at 0xfe024000 irq 23 the playback device "hw:0" is already in use. Please stop the application using it and run JACK again Cannot initialize driver JackServer::Open() failed with -1 Failed to start server
My system is Debian Lenny.
So how can I play sound with JACK started?
(i forgot the list)
Hi Cong, that is the expected behaviour of Jack.
On 18/04/2011, cong fu fc4976@gmail.com wrote: [...]
sudo /usr/bin/jackd -r -m -dalsa -dhw:0 -r44100 -p1024 -n2 -P
I'm pretty sure you don't need to run it with root prileges. Add something like this to /etc/security/limits.conf :
@audio - rtprio 99 #@audio - memlock 5000000 @audio - nice -10 @audio - memlock 378909
If your user is not member of the 'audio' group add yourself, logout and login for changes to take effect.
So how can I play sound with JACK started?
Tell your application to use jack for output. With mplayer for example add '-ao jack'. There's also an alsa plugin, see this:
http://alsa-project.org/main/index.php/Asoundrc#JACK_plugin
-- Adrian. http://ovejafm.com http://elesquinazotango.com.ar
2011/4/18 cong fu fc4976@gmail.com
Hi experts: I installed JACK and the GUI of it looks good. But it seems it will block the "audio application" and "audio application" will also blcok it. That is to say:
- If I started the JACK by:
sudo /usr/bin/jackd -r -m -dalsa -dhw:0 -r44100 -p1024 -n2 -P Then I open my web brower and try to play a streaming song(play by flash), the song can't play!
Do you need to run "jackd" using "sudo" ?
This is normal when your sound card does not support hardware mixing
however both alsa-jack and alsa-pulse plugin are I/O plug
if web browser can use alsa "default" device through "alsa-pulse" plugin to pulseaudio server
in theory the web browser can also use alsa "default" device through "alsa-jack" plugin to jack server
assume that you don't use any OSS aplication any more
participants (3)
-
Adrian Pardini -
cong fu -
Raymond Yau