More than one sound steam at a time?

Fenster

Much as I fiddling with anything sound-related under Linux (I find it a pain in the arse), I want to get more than one sound steam at a time running so I can run Skype on my laptop.

I had a rummage around on Google, nothing too get. Where can I start reading about this out there?

nadir

well you will want to use alsa. Some sound cards work well with alsa, the easy solution is to buy a sound card that has hardware mixing supported by alsa. like a Roland MPU-401 or a soundblaster live. And definately NOT Creative EMU10KX or Audigy,
If you are like me and are too broke to buy a new card, and are stuck with an onboard card you could try dmix

you need to set up ~/.asoundrc something like this

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

pcm.dsp {
type plug
slave.pcm "dmixer"
}

pcm.dmixer {
type dmix
ipc_key 1024
slave {
pcm "hw:0"
period_time 0
period_size 512
buffer_size 32768 #modify this to match your card's buffer size
rate 48000
}
bindings {
0 0
1 1
}
}

ctl.mixer {
type hw
card 0
}

this is the card i have
Multimedia audio controller: C-Media Electronics Inc CM8738 (rev 10)


period_time 0
period_size 512
buffer_size 32768

is very important , This basically controlls quality. If you set them wrong for your card, you will get loads of crackleing and sound will stop randomly.
Its been a while since I played with it, but it was something like the buffer size needs to be the 4th root of period_size or something like that,
basically though, make them large, larger than is said on the alsa web page, it doesn't crash until something like period_size="2^30" or so, but Im guessing using large buffer sizes is like inefficient.

rate 48000 is also important, some people are using 41100 and such, thats basically wrong, because 48000 wont work with it, but 41100 works with 48000, so go figure.

Also if you use mplayer you should set in the config
ao=alsa1x:default
and NOT ao=alsa1x:dmixer
as that messes it all up

it takes a little while to configure, but its working pretty ok here, not perfectly though, I can play music and movies all at the same time no problem, but I still cant play quake 3 and music, quake 3 grabs the audio all for itself, as do some other games. you need hardware mixing support for those. But most other games work ok with it.