Alsa-Devel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Clemens Ladisch <clemens@ladisch.de>
To: Pavel Fedin <sonic.amiga@gmail.com>
Cc: alsa-devel@alsa-project.org
Subject: Re: Independent usage of two channels
Date: Thu, 22 Jan 2009 12:42:38 +0100	[thread overview]
Message-ID: <49785BAE.6090402@ladisch.de> (raw)
In-Reply-To: <187c6cc60901220316i65a1558bm4b7c503db062a01e@mail.gmail.com>

Pavel Fedin wrote:
> Is it possible to use two channels of a sound card as two independent
> devices for PCM playback?

The sound card is probably not able to handle two independent mono
streams, but it is possible to use alsa-lib's software plugins to
emulate two devices on top of the real one.

Put this into your ~/.asoundrc or into /etc/asound.conf:

pcm_slave.stereo_slave {
	pcm "hw:0"          # or "hw:1" for the second card ...
	channels 2
}

pcm.left {
	type plug
	slave.pcm {
		type dshare
		slave stereo_slave
	}
	bindings [ 0 ]
}

pcm.right {
	type plug
	slave.pcm { type dshare slave stereo_slave }
	bindings [ 1 ]
}

Then use device names "left" and "right" instead of "default".


HTH
Clemens

      reply	other threads:[~2009-01-22 11:42 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-22 11:16 Independent usage of two channels Pavel Fedin
2009-01-22 11:42 ` Clemens Ladisch [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=49785BAE.6090402@ladisch.de \
    --to=clemens@ladisch.de \
    --cc=alsa-devel@alsa-project.org \
    --cc=sonic.amiga@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox