[alsa-devel] wrong decibel data?

Raymond Yau superquad.vortex2 at gmail.com
Fri Apr 9 02:49:40 CEST 2010


2010/4/8 Nicolo' Chieffo <nicolo.chieffo at gmail.com>

> I'm sorry but I found out that I gave you wrong values of "amixer -D
> pulse": I just discovered that when I lower the alsa master volume, in
> some occasions the PCM volume goes to 99%, so now I will put it to
> 100% and check the pulse volume again.
>
> 0 dB    =  65536 [100%]
> -3 dB   =  57520 [88%]
> -6 dB   =  52057 [79%]
> -12 dB =  41034 [63%]
> -24 dB =  26090 [40%]
> -48 dB = 10151 [15%]


You have to ask PA developer since  "PCM" is a softvol control with access
'user' and dbmin -51dB

    control.24 {
        comment.access 'read write user'
        comment.type INTEGER
        comment.count 2
        comment.range '0 - 255'
        comment.tlv '0000000100000008ffffec1400000014'
        comment.dbmin -5100
        comment.dbmax 0
        iface MIXER
        name 'PCM Playback Volume'
        value.0 255
        value.1 255
    }


HDA-Intel.pcm.front.0 {
	@args [ CARD ]
	@args.CARD {
		type string
	}
	type softvol
	slave.pcm {
		type hw
		card $CARD
	}
	control {
		name "PCM Playback Volume"
		card $CARD
	}
}


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