Hi Clemens,

Am 10.09.2010 09:18, schrieb Clemens Ladisch:

I'm using the mixer_vol_tlv TLV

...

callback right now but I'm not sure it produces correct data.

Try alsamixer. Or just post the output of "amixer contents" here.

Well, according to alsamixer the mixer values are mapped to a range from 0 to -128 dB.

'amixer contents' show entries of the form

numid=112,iface=MIXER,name='DIn8 - Out7 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=-32768 | unk-4-0xffffce00,0x00000000,

(numid and name changing of xourse for each control ).

Here are some examples of setting values with amixer:

:~$ amixer -c 2 cset numid=1 50% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=16384 | unk-4-0xffffce00,0x00000000,

:~$ amixer -c 2 cset numid=1 80% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=26215 | unk-4-0xffffce00,0x00000000,

:~$ amixer -c 2 cset numid=1 100% numid=1,iface=MIXER,name='AIn1 - Out1 Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=0,max=32768,step=0 : values=32768 | unk-4-0xffffce00,0x00000000,

cat /proc/asound/F8R/usbmixer gives lines like this:

Unit: 5 Control: name="DIn8 - Out7 Playback Volume", index=0 Info: id=5, control=7, cmask=0x8000, channels=1, type="S16" Volume: min=-32768, max=0, dBmin=-12800, dBmax=0

How do I tell the controls value range is correctly mapped to the dB values?

Kind regards,

Felix