[pulseaudio-discuss] How to control the right and left channel for a specific application using CLI ?

[01ivier at labomedia.org]

Le 2020-11-03 23:49, Arun Raghavan a écrit :
> On Tue, 3 Nov 2020, at 5:28 PM, 01ivier at labomedia.org wrote:
>> Hello again,
>> 
>> I want to know if there is a way, still in command line, to control 
>> the
>> right and left volumes of an application.
>> With Pulseaudio Volume Control, you can click on the lock icon related
>> to a launched application, and two sliders appear to do so.
>> Is it possible in CLI ?
>> 
>> My goal is to run two applications on the same card, but to assign 
>> right
>> channel for one and left for the other.
>> 
>> Possible complication : the output of my application is in mono and 
>> with
>> Pulseaudio Volume Control I don't get the two sliders if I click on 
>> the
>> lock icon.
> 
> You can use pactl to do this:
> 
>   pactl set-sink-input <sink input index> <volume for channel 1>
> <volume for channel 2> ...
> 
> You can look up the sink input index and channel map for channel order 
> with:
> 
>   pactl list sink-inputs
> 
> -- Arun

Hello Arun and thanks for the quick answer.

It's exactly the command I was looking for.
Unfortunately, as I thought, it doesn't work in my case because my 
output is in mono.
Here's what I get:
Failed to set volume: You tried to set volumes for 2 channels, whereas 
channel(s) supported = 1

I can't change the output of the software.
Is there possibly a way to create a virtual stereo output from the mono 
?

Thank you.

°1ivier