I can set the devicepriority in phonons KCM also in general: http://funkyimg.com/view/24gyZ This wont take effect sometimes and is also a bit unclear explained in its function, imho As an example: I set my USB speakers on #1 in the general "Audio Playback" output section and the "Build in Audio" for my analog headphones on #1 in the "Games" section. The output goes, when i run dolphin-emu to the headphones and once i change the "Games" option to USB, effect that. On the other hand: When i set the USB speakers to #1 in the general "Audio Playback" section and "Build in Audio" in all the subcategorys (just to be sure) play youtube the music still on the speakers. I already expirience that both in kf5 and KDE SC 4 and different cases. Reproducible: Always
The problem here is that applications are not forced to define their content and even when they do they aren't always right. For example VLC always claims it is playing video even when it isn't. This is rather unfortunate and indeed not clear to the user. The KCM in general is way too complicated, so I think the design choice last this came up was to eventually hide the categories entirely and blanket manage all application categories with one single list. While the list-per-category feature looked nice on paper it is way too complicated and buggy to be useful in practise unfortunately.
I agree with you and was just to shy, to propose such a "radical" step. It might be another method, to open issue reports at the specific app projects, while i think, this wont work in real world. It might be a nice alternative, to create a quick switch between the different sound chips, like in plasma-pa or a notification pop up, as recommended by you in this report: https://bugs.kde.org/show_bug.cgi?id=355168
Created attachment 100903 [details] Are Phonon audio categories for real? Neither Chromium nor SMPlayer cared about the setting for any of the categories under Audio Playback. Is this a gimmick?
It works sometimes. :)