[pulseaudio-discuss] update-card-properties? Possible?

[David Henningsson]

(Sorry if this email reaches you twice, some SMTP problems here)

On 2016-08-17 17:11, Tanu Kaskinen wrote:
> On Wed, 2016-08-17 at 12:55 +1000, Bernd Wechner wrote:
>> But if I've helped spot a pulseaudio bug (failure to copy the HDMI
>> product name to the card description in some way), that's that's nice. I
>> do think it would awesome and seemingly an easy fix to see those HDMI
>> device identifiers in the Sound settings through the card
>> device.description.
>
> Note that the HDMI product name shouldn't be used as the card
> description, at least in most cases, because often a card that provides
> HDMI has multiple devices - there might be analog devices on the same
> card, or multiple HDMI ports. It makes more sense as a port
> description.
>
> The Gnome sound settings output selection list, for example, uses this
> format in the labels:
>
> <port description> - <card description>
>
> If HDMI is provided by the built-in sound card, I guess using the HDMI
> product name as the port description would look like this:
>
> <product name> - Built-in Audio
>
> I'd imagine the "Built-in Audio" part in combination with the monitor
> name would look a bit strange to many users.

Certainly e g "HDMI / DisplayPort - Samsung TV" would look better to me.

> Maybe that's why we
> haven't gone as far as replacing the port description with the product
> name? I'll add David Henningsson to Cc in case he wants to comment.
> He's the one who implemented the monitor name reading.

I would like the monitor name somewhere in the Gnome/Unity UI, and 
perhaps somewhere in pavucontrol as well.

If I try to remember why that never happened, I can think of a few reasons:

  1) Changing UI things (in both Gnome and Unity) require design 
decisions etc which is a heavy-weight process

  2) I was hoping someone else would do it :-)

  3) Somebody warned that the monitor name would be wrong due to 
hardware and/or driver issues

  4) This dynamic HDMI PCM stuff (reprobing etc) that never got 
implemented either - e g, if we want volumes stored per connected 
monitor, then monitor name would become part of the ID somehow, etc, 
maybe then the connected monitor name would actually end up as port (or 
card?) name, and then Gnome/Unity would get it automatically instead...

>
>> As to the simple use case and why someone would like to change the name
>> that is easily answered.
>>
>> 1) USB devices identify themselves with weird or unclear names. HDMI
>> devices similarly. They are techie and device descriptive.
>>
>> 2) These names used as well in the System tray sound apps that allow
>> selection of output device for example.
>>
>> 3) I have family and others using a multimedia machine, as I suspect
>> many do who want to be able to select output device, pump sound into one
>> attached unit or another (I have quite a few).
>>
>> 4) For that reason I'd like freedom to name these devices, in a way that
>> sticks, and ideally survives unplugging and plugging in again, to be
>> meaningful to end users. Names like "Wireless headphones", "Surround
>> sound system", "Bedroom speakers", "FM transmitter" etc, by way of
>> example. As it is essentially with complex sound systems and multiple
>> devices served any user has to try them one by one until they detect
>> sound where they want it. That is neither practical fro all devices nor
>> friendly so most steer clear of it.
>>
>> 5) Further, it'd be nice to name them in the Sound Settings GUI and not
>> have to lay around with config files in /etc if possible.
>
> All these use cases seem like they deal only with the descriptions. You
> made earlier a distinction between card names and card descriptions,
> and it's unclear where you'd need to care about the card name.
>
>> I migrated from Windows a while back and there I could name the sound
>> devices. And I suspect it's managed at a level higher than ALSA, maybe
>> at a level like pulseaudio, and possible even at a higher level still.
>>
>> Getting my head around where this might fit. As I may be in a position
>> to contribute code of course once I know where is most appropriate and
>> how to contribute to the relevant community.
>
> If you decide to start working on the code, feel free to ask any
> questions on this mailing list or in IRC (#pulseaudio at freenode.net).
>
> --
> Tanu
>