using asoundrc to join volume controls?

[DooBeDooBeDo]

I currently use a script to set surround levels on my mythbox as the 'Master' only affects stereo. I was wondering if it's possible to join the volume controls using asound.conf.

Lircd executes the script when the volume is changed, the applications (mythtv/xine) affect Master.

my script is: cat /usr/local/bin/surround_vol

Code: Select all

#!/bin/bash

vol=$(/usr/bin/amixer get Master|/bin/grep Left|/usr/bin/tail -1|/usr/bin/gawk -F ' ' '{ print $4 }')

/usr/bin/amixer set Surround $vol >/dev/null
/usr/bin/amixer set Center $vol >/dev/null
/usr/bin/amixer set LFE $vol >/dev/null

Ideally I'd like to tie the volumes of Surround, Center and LFE to that of Master using asound.conf

my asound.conf currently looks like:

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pcm.ch51dup {
    type route
    slave.pcm surround51
    slave.channels 6
    ttable.0.0 1
    ttable.1.1 1
    ttable.0.2 1
    ttable.1.3 1
    ttable.0.4 0.5
    ttable.1.4 0.5
}

This duplicates stereo to the surround speakers (My speakers automatically mix to the sub if it's not specifically driven).

Does anyone know if this is possible?

[toralf]

emerging media-libs/alsa-lib-1.0.19 gives:

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WARN: postinst
Starting from alsa 1.0.11_rc3 the configuration for dmix is changed.
Leaving around old asound.conf or ~/.asoundrc might make all apps
using ALSA output crash.
Note that dmix output is enabled by default on the 'default' device
since ALSA 1.0.9.

LOG: postinst

Please try in-kernel ALSA drivers instead of the alsa-drivers ebuild.
If alsa-drivers works for you where a *recent* kernel does not, we want 
to know about this. Our e-mail address is alsa-bugs@gentoo.org
However, if you notice no sound output or instability, please try to 
upgrade your kernel to a newer version first.

[DooBeDooBeDo]

toralf: I'm a little confused about what you are implying by your post.

If it helps I'm on alsa-lib-1.0.14a-r1 and kernel 2.6.23-gentoo-r3.

I'm not going to upgrade anything or even emerge --sync (last time it was synced was when it was built) it's a very low powered VIA mini-ITX system running as a front/backend mythtv box which works completely to my satisfaction with the exception of the volume control, which causes xine to stutter if I adjust the volume. I thought it was about time I came up with a better fix than my script.

[toralf]

I mean this :

Leaving around old asound.conf

therefore it is a bad idea to create such a file, isn't it ?

[DooBeDooBeDo]

OK I understand now I think. It's just a warning that the syntax/options changed. Not a notice to stop using the file(s) for configuration.

Please correct me if I'm wrong, or point to somewhere where it's stated other than that message.

[toralf]

Please correct me if I'm wrong, or point to somewhere where it's stated other than that message.

Oh no, you're right.