Re: [Alsa-user] One process per audio channel

[John S. <lin...@fr...>]

Hello Jaroslav,

Jaroslav Kysela wrote:

> John Sigler wrote:
> 
>> I have an RME AES-32 PCI board which provides 4 stereo input channels 
>> and 4 stereo output channels.
>> 
>> (I'm using the hsdpm driver at this time.)
>> 
>> I want to use one process per channel, i.e. process A handles stereo 
>> input #1 (on the XLR connector #1), process B handles stereo input #2, 
>> etc.
>> 
>> The processes are independent, in that process A might be started, and 
>> only several hours later, process B is started, then a few hours later 
>> process A is killed and restarted.
>> 
>> Is it possible to do that with the ALSA library?
> 
> Yes, look for the dsnoop plugin configuration in alsa-lib.

Thanks for the tip. I will investigate. I must say that the ALSA 
configuration files look like pure voodoo magic to me.

I found the following documentation:

doc/asoundrc.txt
http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html
http://alsa.opensrc.org/.asoundrc
http://alsa.opensrc.org/Dsnoop
http://alsa.opensrc.org/AlsaTips

Is there any other good documentation?

How can alsa-lib open a device node several times when the driver
only allows one process to open it?

I see references to "ipc" in alsa.conf.

My embedded kernel is compiled with
# CONFIG_SYSVIPC is not set

Does the dsnoop plugin require kernel support?

-- 
Regards.