[pulseaudio-discuss] Devices with dynamic capabilities (HDMI) - revisited

David Henningsson david.henningsson at canonical.com
Thu Jan 17 06:14:37 PST 2013


Two months since PulseConf, and 3.0 is out there. So, time to start 
thinking again about what we talked about at PulseConf.

So, on my TODO list were separate cards for HDMI. According to Arun's 
report, the conclusion was to use "dynamic profiles" and have the card 
always present. I don't remember exactly why though.

Anyway, I'm proposing that cards are dynamically added and removed as 
HDMI monitors are plugged in and out, for the following reasons:

  1) An HDMI monitor is a lot like a USB card in that sense that it 
affects the streaming capabilities. Assuming we add some part of the ELD 
info as the card name, it enables us to save information per monitor 
rather than per output, so that, e g, when a user's laptop is connected 
to his TV at home, audio gets rerouted, but not when he's connecting to 
his projector at work, or something like that.

  2) As we then won't have four always-present cards/sinks/ports which 
are unavailable [1], my argument for hiding unavailable ports in the GUI 
is no longer valid; we could potentially make them grey instead.

  3) Last but not least, no GUIs currently support "dynamic profiles" 
and I hate breaking other stuff. But as they already deal with USB 
cards, this new feature will not mean any new logic for them.

David Henningsson, Canonical Ltd.

[1] In case you don't remember, this is a hardware limitation on several 
generations of HDA graphics cards - they have up to four ports which 
show up as "unavailable" even if they are not soldered to anything.

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