AlsaScenarios

Introduction

This article assume that the porter is familiar with fso config files. We will take the gta04 hardware as an example. We will make the stereoout scenario.

Howto

• let's go at the gta04 documentation page

we see some amixer commands:

#Basic
amixer set 'DAC1 Analog' off
amixer set 'DAC2 Analog' on
amixer set 'Codec Operation Mode' 'Option 1 (audio)'

And:

#Handsfree
amixer set HandsfreeL on
amixer set HandsfreeR on
amixer set 'HandsfreeL Mux' AudioL2
amixer set 'HandsfreeR Mux' AudioR2
aplay /usr/share/sounds/alsa/Front_Center.wav 
amixer set HandsfreeL off
amixer set HandsfreeR off

• let's make some dump:

alsactl -f dump.state store

• looking into Basic we see:

amixer set 'Codec Operation Mode' 'Option 1 (audio)'

• we then look into our dump of the alsa states and find that:

        control.1 {                        
                iface MIXER         
                name 'Codec Operation Mode'
                value 'Option 2 (voice/audio)'
                comment {             
                        access 'read write'
                        type ENUMERATED
                        count 1
                        item.0 'Option 2 (voice/audio)'
                        item.1 'Option 1 (audio)'
                }
        }

• the rest is the understanding of the fsodeviced states format:

1:'Codec Operation Mode':1:1
|              \          \ \
 \              \          \ \->that correspond to the control value(here 'Option 1 (audio)' )
  \              \          \->that correspond to the numbers of controls, if there were 2 controls it would look like that: :2:1,1"
   \              \->that corresponds to the name of the control
    \->that correspond to the control number (control.1)