How to adjust sound volume from a script?

[holck]

I am a quite happy user, running LXDE on my small eee 901 notebook.

I would like to be able to control the sound volume and to mute/un-mute sound from a small program or script, but it is a little more complicated and strange than I thought.

When I first enter the LXDE session, the volume control applet in the panel shows sound as muted, and volume = 0. I would guess that the commands below would change this:

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$ amixer cset iface=MIXER,name='Speaker Playback Switch' on
$ amixer cset iface=MIXER,name='Speaker Playback Volume' 50

But apparently nothing happens. If I now un-mute sound, using the applet, and issue this command

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$ amixer cset iface=MIXER,name='Speaker Playback Switch' off

the applet shows the sound as muted. Now I can turn on sound again with

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$ amixer cset iface=MIXER,name='Speaker Playback Switch' on

Volume is still 0, and the following command doesn't change this:

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$ amixer cset iface=MIXER,name='Speaker Playback Volume' 50

But I can turn up volume on the applet (to e.g. 100) and now control volume via the command line

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$ amixer cset iface=MIXER,name='Speaker Playback Volume' 50

sets volume = 58

Strange, isn't it? Any help appreciated
Jesper, Denmark

[maces]

Hi,

here is my script, works quite well for me:

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#!/bin/sh

usage="usage: $0 -c {up|down|mute} [-i increment] [-m mixer]"
command=
increment=1%
mixer=Master
mic=Mic

while getopts i:m:h o
do case "$o" in
    i) increment=$OPTARG;;
    m) mixer=$OPTARG;;
    h) echo "$usage"; exit 0;;
    ?) echo "$usage"; exit 0;;
esac
done

shift $(($OPTIND - 1))
command=$1

if [ "$command" = "" ]; then
    echo "usage: $0 {up|down|mute} [increment]"
    exit 0;
fi

display_volume=0

if [ "$command" = "up" ]; then
    display_volume=$(amixer set $mixer $increment+ unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
fi

if [ "$command" = "down" ]; then
    display_volume=$(amixer set $mixer $increment- unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
fi

if [ "$command" = "micup" ]; then
    display_volume=$(amixer set $mic $increment+ unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
    display_volume=$(amixer set "Front $mic" $increment+ unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
fi

if [ "$command" = "micdown" ]; then
    display_volume=$(amixer set $mic $increment- unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
    display_volume=$(amixer set "Front $mic" $increment- unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
fi

icon_name=""

if [ "$command" = "mute" ]; then
    if amixer get Master | grep "\[on\]"; then
        display_volume=0
        icon_name="notification-audio-volume-muted"
        amixer set $mixer mute
    else
        display_volume=$(amixer set $mixer unmute | grep -m 1 "%]" | cut -d "[" -f2|cut -d "%" -f1)
    fi
fi

if [ "$icon_name" = "" ]; then
    if [ "$display_volume" = "0" ]; then
        icon_name="notification-audio-volume-off"
    else
        if [ "$display_volume" -lt "33" ]; then
            icon_name="notification-audio-volume-low"
        else
            if [ "$display_volume" -lt "67" ]; then
                icon_name="notification-audio-volume-medium"
            else
                icon_name="notification-audio-volume-high"
            fi
        fi
    fi
fi
notify-send " " -i $icon_name -h int:value:$display_volume -h string:synchronous:volume

call it like that:

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vol.sh up -i 1% -m Master
vol.sh down -i 1% -m Master
vol.sh micdown -i 1% -m 
vol.sh micup -i 1% -m 

And for muting use this:

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amixer set Master toggle

Don't know if it works with eeepc901 immediately. Hope it helps.

maces

[Marty Jack]

An interesting fact to know is that the mixer that is controlled by the Volume applet is in the device "default", the first of "Master", "Front", "PCM", and "LineOut" that is found. I do not believe this is the one the original poster is setting with their script.

We expect to make this configurable in a future release. It is not going to be easy because of the great variety of ways that the sound system can be set up, particularly if you factor in PulseAudio, and because of the abstraction level of the ALSA API.

[holck]

Thanks for the help and the script - but unfortunately, the script did not solve my problem.

I have done some experimentation, and the small script below seems to work for me, i.e. it unmutes sound:

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amixer sset 'Master' 50 unmute
amixer sset 'Speaker' 50 unmute
amixer sset 'Headphone' 50 unmute

One thing I found out is that isn't enough to unmute just one control, you have to unmute several, including "Headphone".

Jesper,
Denmark

[rockdoctor]

Don't know if it's relevant, but on my Acer Aspire One, I find I need to up the setting on the 'Beep" device too