[Alsa-user] Questions about /proc/asound/pcm

[Gian P. M. <the...@sl...>]

    I know that this question would be better suited for the devel list, 
but I do not have an account for it, so please excuseme for asking this 
in this list...

    I've tried so hard to undestand why nForce2 sound "cards" are so 
problematic when you want more than one source of audio (when they 
supposedly support up to 64 different sources). In my quest to 
specifically get to work TeamSpeak with other applications (not even 
ALSA aware apps produce any sound, like XMMS using the ALSA plugin, 
though aplay works (not alsaplayer)... go figure). At any rate, one of 
the docs I read suggested taking a look at what `cat /proc/asound/pcm` 
returned, and so I did. I currently have a VIA based MoBo and my old 
trusty SoundBlaster Live!, and did this with them three, here are the 
outputs (nForce2 output may be wrong, but since I only wrote down the 
first line, the other I write it off the recesess of my memory):

SB-Live! Value:
00-00: emu10k1 : EMU10K1 : playback 32 : capture 1
00-01: emu10k1 mic : EMU10K1 MIC : capture 1
00-02: emu10k1 efx : EMU10K1 EFX : playback 8 : capture 1

VIA VT8235:
01-00: VIA 8235 : VIA 8235 : playback 4 : capture 1
01-01: VIA 8235 : VIA 8235 : playback 1 : capture 1

nForce2:
00-00 : nforce2 : NFORCE2 : playback : 1 : capture 1
00-01 : nforce2 : NFORCE2 : playback : 1

I do not understand what all these playbaks are in the case of the Live! 
and the VIA, are they sources or "devices"? (since I remember that the 
emu10k1 spec said it supported 32 HW voices back in the day, then 
unlocked to 64 in the Audigy (I think. It'd be interesting to see what 
does an Audigy/Audigy2 reports). As I said before I'm not sure about the 
second line in the case of the nForce card (though I'm pretty sure it 
was only ONE playback *without* a capture). In any case this playback 
numbers in the first line surely mean how "polyphonic" a sound card can 
be, either with HW mixing or SW (AFAIK the VIA does NOT support HW 
mixing, as stated in the project's page, while the Live! does).

I know Creative cards based on the Emu10k1 chip have an edge here 
because Creative was quite open back in the Live! days. However these 
numbers intrigue me, as they seem to determine how many audio sources 
can be played at once... Are these PCM playbacks OSS-emu specific or are 
they for ALSA native/OSS-emu?

Thanks!

PS: I've seen in the list the request for an NFORCE2 donation so AC3 and 
SPDIF would work with ALSA and maybe as a side effect get this "fixed" 
too... Though I don't own an nForce2 board, I support anything that 
broadens Linux support ;)