[pulseaudio-discuss] My opinion on Tanu's "second volume control" proposal

[Alexander E. Patrakov]

Tanu proposed:

> 3) Add a second volume control to streams, one which represents the
> stream's own volume only, i.e. never flat volume. Applications that want
> to avoid flat volume can use that volume control instead of the primary
> volume control.
>
> Even if proposals 1 and 2 are implemented, I'd still like to implement
> proposal 3 too, because it's simple (I need the second volume control at
> server side anyway, and adding it to the client API is just a matter of
> adding one field to pa_sink_input_info and pa_source_output_info) and
> because it provides some new possibilities for applications: for
> example, pavucontrol could have an option to not show flat volumes even
> when flat volumes are enabled.

The idea is well supplanted with a use case, but I think that this could 
use some more discussion.

The potential problem with "just exporting" the field is that the 
proposal specifies only one additional volume factor with no clear 
ownership policy, and I am afraid that various agents (the server and 
the client) will fight over it. OTOH, especially if we design the API to 
avoid "set this extra volume to this value" operation and only allow 
relative changes, this may as well be a non-problem.

Maybe, instead of having one extra volume control, we need to be able to 
create and destroy additional possibly-invisible volume controls on 
as-needed basis, with the final extra gain determined by the product of 
their volumes? E.g., one volume can be used for volume groups, one can 
be used for ducking when it is in effect, and one for client-specific needs.

-- 
Alexander E. Patrakov