[linux-audio-user] asoundrc magic for multi outs

[linux-audio-user@xxxxxxxxxxxxxxxxxx (Ross Vandegrift)]

Hello all,

	I have a session comeing up this weekend where I'll need three
set of headphones monitoring the mix.  This is a problem, since I have a
Delta44, and am limited to four channels of output.  I also have an
SBLive I use for MIDI, and I'm trying to make a virtual device to take
advantage of that output as well.

	I started with the asoundrc in the wiki for this in the wiki, at
http://alsa.opensrc.org/index.php?page=TwoCardsAsOne but if I try to
aplay to it:

ross@turalyon:~$ aplay -D multi synth.wav
Playing WAVE 'synth.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
aplay: set_params:783: Broken configuration for this PCM: no configurations available

I pretty much snipped the config directly, and added lines for my
additional channels.  I also tried making a copy device, but this plays
for a second (out of the Live) and then quits with an I/O error:

ross@turalyon:~$ aplay -D copy synth.wav
Playing WAVE 'synth.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
aplay: pcm_write:1025: write error: Input/output error

Here's my ~/.asoundrc:

pcm.multi {
        type multi;
        slaves.a.pcm "hw:0,0";
        slaves.a.channels 4;
        slaves.b.pcm "hw:1,0";
        slaves.b.channels 2;
        bindings.0.slave a;
        bindings.0.channel 0;
        bindings.1.slave a;
        bindings.1.channel 1;
        bindings.2.slave a;
        bindings.2.channel 2;
        bindings.3.slave a;
        bindings.3.channel 3;
	bindings.4.slave b;
	bindings.4.channel 0;
	bindings.5.slave b;
	bindings.5.channel 1;
}

ctl.multi {
        type hw;
        card 0;
}

pcm.ttable {
        type route;
        slave.pcm "multi";
        ttable.0.0 1;
        ttable.1.1 1;
        ttable.2.2 1;
        ttable.3.3 1;
	ttable.4.4 1;
	ttable.5.5 1;
}
ctl.ttable {
        type hw;
        card 0;
}

pcm.copy {
	type copy;
	slave.pcm "hw:0,0"
	slave.pcm "hw:1,0"
}

Thanks for any tips!


-- 
Ross Vandegrift
ross@xxxxxxxxxxxxxxxx

A Pope has a Water Cannon.                               It is a Water Cannon.
He fires Holy-Water from it.                        It is a Holy-Water Cannon.
He Blesses it.                                 It is a Holy Holy-Water Cannon.
He Blesses the Hell out of it.          It is a Wholly Holy Holy-Water Cannon.
He has it pierced.                It is a Holey Wholly Holy Holy-Water Cannon.
He makes it official.       It is a Canon Holey Wholly Holy Holy-Water Cannon.
Batman and Robin arrive.                                       He shoots them.