[fso based] Simplified mixer app

Al Johnson openmoko at mazikeen.demon.co.uk
Thu Oct 1 23:24:19 CEST 2009

I've made mixer app that maps a single slider to multiple alsa channels, so 
you can have one slider for 'Mic' and another for 'earpiece'. It's based on 
Angus Ainslie's fso-mixer, but using lookup tables for which channels to show 
in which scenario, and for mapping the single slider to multiple channels.

It's at proof of concept stage now, but should be as functional as fso-mixer. 
I hope. If you aren't using stock ones it would be a good idea to back them up 
before using it just in case! Feedback would be welcome.


Known bugs and missing features:
* I haven't done mapping tables for all the mixer scenarios yet. Where they 
aren't done you will see the individual sliders as you would in fso-mixer.
* Sometimes when the state changes a setting will be shown as 0 when it is in 
fact non-zero. If anyone spots why this happens I would love to know!
* The volume sliders cover the whole possible range, while most people 
probably only ever need the top half or third.
* pyalsaaudio only accepts integer percentages when setting volumes, not the 
actual mixer hardware values used in the lookup tables. This may give some 
uneven steps in volume.
* When individual alsa channels are shown they use the alsa names. This is 
fine if you know that the 'headphone' mixer controls the speaker, and the 
'speaker' control is for the earpiece, let alone some of the more obscure 

More information about the community mailing list