External control through MPRIS doesn't work in Firefox

[maxigaz]

Web browsers like Firefox and Chromium and several media players support MPRIS under Linux. This allows one to do any of the following:

• Create notifications or panel widgets that display the author and/or title of the currently played music or video.
• Control the player with global keyboard shortcuts assigned to commands such as stop, pause, play, previous/next song, increase/decrease volume etc.
• Control the player remotely with the Android application KDEConnect.

With Firefox, all of the above works when I open a video (e.g. on YouTube) or play an audio file, like this one on Wikipedia. This can also be confirmed by having playerctl installed (the program I use most of the time for control and custom notifications and widgets) and running playerctl -l in the terminal while the video or sound file is being played or paused; Firefox shows up in the output.

As I've been testing on Manjaro and Arch Linux, it seems like playerctl cannot detect Generative.fm at all while it's playing in Firefox (v94.0), but only in Chromium (v95.0.4638.69). I'm not sure if this is caused by a bug in Firefox or something needs to be changed on the side of Generative.fm for this to work.

As a sidenote, I'd like to thank you for making this amazing tool.

[alexbainter]

Hi @maxigaz! I'm not familiar with MPRIS but I would guess it uses the Media Session API to detect and control web media. Generative.fm does use the Media Session API but maybe I'm missing something to make it work properly in Firefox; I just checked and it's not working for me either on Elementary OS (Ubuntu).

I'll take a look into this and see what I can do. Thanks!