[SOLVED] amixer and alsamixer differences

oarmstrong · 2013-12-30 14:47:59

Hi. When I started this install I installed cinnamon DE to test it out. As expected it conveniently set up all the audio stuff for me (using what appeared to be pulseaudio with ALSA). With this I was able to use `amixer set Master 10%` (for example) and it would correctly set the audio volume to 10%, reflected by stdout of that command and `alsamixer`.

However, now I've switched back to dwm and after having issues with pulseaudio I switched back to the standard ALSA set up. The problem now is that if I execute the command `amixer set Master 10%`, stdout returns that it has set it to 12% and alsamixer shows 3/100 on the bar.

Is there anything I can do to get amixer and alsamixer to play nice together again? If not, is there a better way of setting the volume through a command which is reliable? Also I would need a way of reading the current volume as I have that displayed in my dwm status bar (with xsetroot -name).

Also, when I run `amixer set Master 5%+` (which is bound to my media volume increase key) it will increase by somewhere in the region of 6-8% depending on what is is before running.

Any pointers would be appreciated. I don't necessarily need to fix this inconsistency, only need a way of setting and getting the current ALSA volume through a command which is consistent with the actual audio volume as reported by alsamixer.

Last edited by oarmstrong (2013-12-30 15:03:50)

karol · 2013-12-30 14:59:21

https://bbs.archlinux.org/viewtopic.php?pid=1054701
'amixer set Master 10%' returns 13% in stdout and 5/100 in alsamixer here.

Last edited by karol (2013-12-30 14:59:57)

oarmstrong · 2013-12-30 15:03:37

karol wrote:

https://bbs.archlinux.org/viewtopic.php?pid=1054701
'amixer set Master 10%' returns 13% in stdout and 5/100 in alsamixer here.

Thanks, this post explained exactly how to get amixer to user alsamixer units.

Trilby · 2013-12-30 15:07:32

I suspect it is just a matter of how alsamixer does it's rounding. If you dig into /proc/asound/ you'll see that volume levels are not stored in percents, but rather a hex value which in my case ranges from 0 to 0x4a (or 74) and has a step size of 0x03. 74/3 is 24.6666 actual steps possible. 24.6666 * 10% = 2.46666 which could be rounded down to 2, or up to 3. 2 / 24.6666 = 12.16 % which in turn might get rounded for display.

Arch Linux

#1 2013-12-30 14:47:59

[SOLVED] amixer and alsamixer differences

#2 2013-12-30 14:59:21

Re: [SOLVED] amixer and alsamixer differences

#3 2013-12-30 15:03:37

Re: [SOLVED] amixer and alsamixer differences

#4 2013-12-30 15:07:32

Re: [SOLVED] amixer and alsamixer differences

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