[proaudio] JACK and ALSA

[Dominique Michel <dominique.michel@xxxxxxxxx>]

As the archive is member only, I reproduce here the message of Kjetil
Matheussen on the jack-devel list:

I used this setup a while too, but it didn't work
very well. There was a latency on around a second,
and I also got some scratching noises now and then.

So a while ago (still), I changed my .asoundrc file like this:

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

pcm.jack {
    type plug
    slave { pcm "rawjack" }
    hint {
  description "JACK Audio Connection Kit"
    }
}

pcm.!default {
    type plug
    slave { pcm "rawjack" }
}


And suddenly I got no noticable delay, no scratching
sounds now and then, and almost no trouble [1].

What am I missing? Why run through the trouble
of setting up alsa_in, do the loop-thing, scripting,
and so forth?

[1] Only trouble: I have to restart the chrome
browser after stopping and starting jack.

#############

That's all. With a simple .asoundrc, we can interface jack and alsa
with almost no latency, and the alsa applications appear into the jack
graph.

To test it, some good music to begin this new year, Pio Leiva and The
Hijos of Cuba in concert in Tokyo:
https://www.youtube.com/watch?v=qmZESHiAqdg

Dominique