Re: ALSA / DMIX

["B. Douglas Hilton" <bdhilton@atlanticbb.net>]

First, why use xmms when Alsaplayer is so cool? Its really good IMHO. 
Alsa is great, especially if you are a musician or work with midi or 
such. Nothing beats it.

For mplayer, hmm... mine works and is self compiled, make sure you have 
your kernel source compiled and supposedly it will detect alsa headers 
and such. Even if if has to use oss fallback that should still work ok.

It took me some tinkering around to get alsa working on my system but it 
is definately superior to anything else around. If it even works at all 
then thats a real good sign.

Tip: try killing esd if its running, there's some bug with it that it 
grabs /dev/dsp and locks it so it really screws up alsa apps.

Tip2: compile your kernel with static sound, (no modules), debian alsa 
will grumble a bit about no modules found but it all should work. A 
static kernel sometimes isn't a bad idea for a laptop since your 
hardware is known and immutable. I usually build all static support for 
laptop internal devices and modules for pluggable things like USB, 
serial, parallel, etc.

- Doug



Nicolás Velásquez O. wrote:

> Hello there,
>
> My system:
> - Dell, Inspiron 5100
> - Debian sarge
> - snd_intel8x0
> - Self compiled kernel 2.6.7
>
> I've had not so nice experiences (neither dmix nor asym) with it:
> - Using xmms, if there is a lot of disk usage, audio will stop playing.
> - Using (self compiled) mplayer, the audio won't play well.
>
> Solutions: (better solutions are welcome!!!!!!)
> - xmms, use xmms through arts (and arts through alsa)
> - MPlayer, give cache to the default alsa device.
>
> Solutions drawbacks:
> - xmms, arts ain't that good, some audio files will play lossy.
> - MPlayer, none.
>
> Links:
> http://alsa.opensrc.org/index.php?page=DmixPlugin
> http://alsa.opensrc.org/index.php?page=asym
>
>
>
> My /etc/asound.conf:
> #asym fun start here. we define one pcm device called "dmixed"
> pcm.dmixed {
>       type dmix
>       ipc_key 1025
>       slave {
>                pcm "hw:0,0"      # you cannot use a "plug" device
> 						#here,darn.
>                period_time 0
>                period_size 1024  # must be power of 2
>                buffer_size 8192  # dito. It
>                #format "S32_LE"
>                #periods 128      # dito.
>                #rate 8000        # with rate 8000 you *will* hear,
>                                  # if ossmix is used :)
>       }
>       bindings {
>               0 0
>               1 1
>       }
> }
>
> #one called "dsnooped" for capturing
> pcm.dsnooped {
>        ipc_key 1027
>        type dsnoop
>        slave.pcm "hw:0,0"
> }
>
> #and this is the real magic
> pcm.asymed {
>        type asym
>        playback.pcm "dmixed"
>        capture.pcm "dsnooped"
> }
>
> #a quick plug plugin for above device to do the converting magic
> pcm.pasymed {
>        type plug
>        slave.pcm "asymed"
> }
>
> #a ctl device to keep xmms happy
> ctl.pasymed {
>        type hw
>        card 0
> }
>
> #for aoss:
> pcm.dsp0 {
>        type plug
>        slave.pcm "asymed"
> }
>
> ctl.mixer0 {
>        type hw
>        card 0
> }
>
> # alsa default card
> pcm.!default {
>       type plug
>       slave.pcm "asymed"
> }
> #done
>
>
> El Vie 09 Jul 2004 18:37, Chris Metcalf escribió:
>  
>
> > Has anybody had a good experience getting the Dmix plugin working
> > well with ALSA?
> >
> > I'm trying to get my laptop (Thinkpad X31 using the snd_intel8x0 ALSA
> > module) to be able to play more than one wave channel at once, but
> > I'm not having much success.
> >
> > Any helpful direction (howtos, good/bad experiences, alternate
> > methods) would be appreciated.
> >
> > Thanks,
> > --
> > Chris Metcalf
> > chris@chrismetcalf.net
> > http://chrismetcalf.net
> >    
>
>