After changing my desktop from Arch Linux to NixOS, playing HTML5 videos in Firefox has become buggy. They will fast forward when you play them, but only when using the USB audio adapter. Pulseaudio is used and ALSA is configured to use pulseaudio as well. A few solutions I found stated that I had to install pavucontrol and disable all other audio adapters and try to change the output from digital to analog, none of which made a difference. When I connect my speakers to the built-in adapter, the problem is resolved, the HTML5 videos in Firefox will play as they should. The only error message I got was that an assertion failed about it not being a GVC mixer. Which I could source back to the following code:g_return_val_if_fail (GVC_IS_MIXER_CARD (card), 0);However I do not know whether this is the real cause, or how to resolve it, but since it worked fine on Arch Linux, it should be fixable.
USB audio adapter causes HTML5 videos in Firefox to fast forward
audio;nixos;usb audio