On Sun, 29 Feb 2004, Stuart Pook wrote:
> > > Please give more information. I have a Audiotrak Maya EX7 (USB)
> > > (8 channels) and would love to use it as 2 (or 3 or 4) stereo devices.
>
> Clemens, I followed your advice and wrote the following .asoundrc.
> The device pcm.main works with aplay, alsaplayer and xmms (without
> the mmap option) but it doesn't work with libao2 version 0.8.4-1.1
> (Debian). Attempts to send sound to the device just hang (please see
> below).
Probably wrong usage of ALSA API. Same thing does artsd - it does not
watch the file descriptors in a way which conforms to ALSA API.
> One problem that I have with this setup is that if I connect mplayer
> to pcm.main then plug resamples to 44100Hz even if, for example, I am
> playing a 32000Hz sample that my hardware can play directly. This almost
> doubles the CPU used by mplayer. I guess that there is no way around
> this (which is why I still have pcm.mplayer). (I chose 44100Hz as the
> default because I normally play MP3s.)
It's a bit problem. The current implementation works with fixed
parameters, because I think that it's much better to predict/force
the output stream parameters rather than doing this in a "auto" way.
Imagine that you play 32kHz file and then you'll start to play 44.1kHz
file. In the scheme, when first hit sets parameters, you'll end up with
downmixing of the 44.1kHz source to 32kHz which is much worse than
upsampling 32kHz to 44.1kHz etc.
Yes, the current resampling algorithm is not best. We need to integrate
a better one to alsa-lib. I'm still looking for a volunteer.
Jaroslav
-----
Jaroslav Kysela <[EMAIL PROTECTED]>
Linux Kernel Sound Maintainer
ALSA Project, SuSE Labs
-------------------------------------------------------
SF.Net is sponsored by: Speed Start Your Linux Apps Now.
Build and deploy apps & Web services for Linux with
a free DVD software kit from IBM. Click Now!
http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click
_______________________________________________
Alsa-user mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/alsa-user
