[alsa-devel] Only one element for multichannel mixer controls please!

Lennart Poettering mznyfn at 0pointer.de
Sat Oct 25 01:49:33 CEST 2008


It seems that quite a few ALSA drivers for multichannel sound cards
export three seperate stereo mixer controls to control front, rear and
center/lfe independantly. That sucks because a client (such as
PulseAudio) cannot make use of this. Instead they should export a
single 6ch mixer control!

The "amixer scontents" output looks very strange for these drivers
since it lists a "Rear" control that as a "Front Left" and a "Front
Right" channel. So, what is it now: front or rear?

Is there any reason for this current driver behaviour? I mean, the
mixer knows channel ids like SND_MIXER_SCHN_REAR_LEFT perfectly
well. Or is it that those devices have some devices joined and this
cannot be expressd with a single boolean "joined" for each

Please enlighten me!


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

More information about the Alsa-devel mailing list