[linux-audio-user] Quattro: part two of mail :-/

[Patrick Shirkey]

Denis de Leeuw Duarte wrote:
>

 >The .asoundrc comments say that quattro1 is pcm0, but what exactly is 
 >pcm0? Is that outputs 1 and 2 viewed as a stereo card?

Yes.

 >I also don't really understand what all the other things are for, like 
 >quattro, q4, and q4b or how I could do practical things like record or 
 >play on one specific in/ouptut.

You need to learn how to use arecord or another app for that.

 >Would you consider rewriting your comments in the file so they are 
more >understandable to those not familiar with the intricacies of 
asoundrc >and low level alsa stuff?

I could do this but the details are all covered in the docs for the 
asoundrc file.  To write more comments seems like a double up to me.

If you want to submit something that makes more sense to you then please 
do so. I may have come to far to be able to understand what it's like to 
be a n00b with ALSA anymore.

> ..and something similar to explain the differences between the q4, q4b 
> and quattro entries. It would be great if you would want to do this, 
> because it would save people the time of having to grok the whole 
> .asoundrc syntax themselves.
> 

pcm0 is the first physical i/o on the device. pcm1 is the second etc...

For the quattro: pcm0 is input1,2 and pcm1 is input 3,4.

- You cannot use the quattro entry by itself.
- The q4 entry means that alsa will do software resampling at the cost 
of some (as yet unmeasured) latency.
- The q4b means alsa wont do software resampling so your audio may sound 
slow or fast if you use the wrong sample rate for playback but you can 
get better latency performance.





-- 
Patrick Shirkey - Boost Hardware Ltd.
Http://www.boosthardware.com
Http://www.djcj.org - The Linux Audio Users guide
========================================

Being on stage with the band in front of crowds shouting, "Get off! No! 
We want normal music!", I think that was more like acting than anything 
I've ever done.

Goldie, 8 Nov, 2002
The Scotsman