[pulseaudio-discuss] module-device-restore: Volume save and restore for all ports?

[Tanu Kaskinen]

Hi Colin,

I got a bit confused about the term "port" in your mail. Apparently you
used it to mean something else than pulseaudio's own "device port"
concept. In this message I will use the word "port" only for the
pulseaudio concept.

ke, 2009-12-30 kello 13:26 +0000, Colin Guthrie kirjoitti:
> As jack sensing will eventually be with us, it would make sense to save
> and restore the volume of all ports separately. Only saving the current
> port's volume would be a pain.

I agree, although I don't really see how jack sensing is important here.
AFAIK ports are currently only implemented by the alsa modules, and in
that case separate ports are created for two different purposes:
selecting the physical output or input, and selecting any options that
the alsa mixer offers (for example, extra amplification switch).
Regardless of jack sensing, volume should be saved and restored
independently for each output/input.

Now the second purpose of ports causes problems: the volume shouldn't be
saved independently for the two cases of whether the extra amplification
is on or off.

I may have not thought this completely through, but nevertheless I
propose the following:

- Track port volume and mute individually. That is, whenever the active
port is switched, the previous port's volume and mute state should be
saved to a database and the new port's volume and mute state should be
loaded from the database.
- Don't treat the options as separate ports, but create a new concept
for them: port options.
- Thereby a port equals a physical route ("port" might be renamed to
"route", although I think "port" is a good enough name for the concept).
- Port options are things that you can switch on and off, or choose from
an enumeration.
- Obviously "port options" are specific to ports. module-device-restore
tracks the option states along with port volume and mute.

Lennart, any comments? Would you accept a patch that made these changes?
I'm not saying that I would definitely write the patch, but it's not
impossible either.

-- 
Tanu Kaskinen