[PlanetCCRMA] jack - howto?

Kevin Bowen kevin@ucsd.edu
Sun Apr 6 18:16:00 2003


Hello,
I'm new to audio on linux, just started installing bits and pieces of 
planetCCRMA... first thing I'm trying to get working is jack-rack, but I 
can't get it to actually output any sound. Alsa is set up and working (I can 
play and record with aplay and arecord) but I'm not sure what I need to have 
in my .asoundrc... I have a soundblaster live. Following the directions on 
the alsa site, I put the following in my asoundrc:
        pcm.emu10k1 {
	type hw
	card 0
	}

	ctl.emu10k1 {
	type hw           
	card 0
        }
Now I can start up jackd with 'jackd -d alsa -d emu10k1' and jack-rack will 
launch and load a bunch of effects, but no sound ever comes out. 

Following the alsa docs further, I see the part about the alsa 'jack 
plugin'... it doesn't really explain what this is or if its necessary, but 
says to get it working, you need to build alsa with configure --with-jack... 
well I didn't build my own alsa, I used the Planet RPMS... I would assume 
that they would have been built with the jack plugin if it was necessary, 
right? Or am I being overly optimisitc? Assuming so, I went ahead and added 
the following lines to my .asoundrc as instructed:
	pcm.jackplug {
	        type plug
	        slave { pcm "jack" }
	}

	pcm.jack {
	        type jack
	        playback_ports {
 	               0 alsa_pcm:playback_1
 	               1 alsa_pcm:playback_2
 	       }
 	       	capture_ports {
 	               0 alsa_pcm:capture_1
                	1 alsa_pcm:capture_2
        	}
	}

But this doesn't change anything. If I try to start up jackd with device 
'jack' or 'jackplug' it fails with:

ALSA lib dlmisc.c:107:(snd_dlsym_verify) unable to verify version for symbol 
_snd_pcm_jack_open
ALSA lib pcm.c:1783:(snd_pcm_open_conf) symbol _snd_pcm_jack_open is not 
defined inside (null)
ALSA: Cannot open PCM device alsa_pcm/jack
cannot load driver module alsa
jack main caught signal 15

What am I missing?

Kevin Bowen
kevin@ucsd.edu