[alsa-devel] Audio codec volume control

[Peter Ujfalusi]

On 09/20/2012 01:08 PM, Rajeev kumar wrote:
>> case 3:
>> 1. Provide master volume control
>> 2. stereo volume control for the left/right channel
>>
> 
> You mean to say
> Left and Right should be a single stereo control which can be provided with
> SOC_DOUBLE. Actually case 2 corresponds to the same setting which you are
> suggesting.
> 
> But why this is better option?

You have less controls for the codec -> easier for users.
Users still can adjust the left/right differently if they want.

> In case user wants a separate left/right volume control then how this setting
> is going to help.

In most cases you change both left/right channel:
amixer sset 'PCM' 8 # left/right volume is 8

but users can set different volume per channel:
amixer sset 'PCM' 8,1 # left volume is 8, right is 1

it is better than:
amixer sset 'PCM Left' 8 # left volume is 8
amixer sset 'PCM Right' 8 # left volume is 8

or
amixer sset 'PCM Left' 8 # left volume is 8
amixer sset 'PCM Right' 1 # left volume is 1

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