Hector Martin

It’s 2018 and you can run Crysis on integrated graphics, but Linux still can’t play two sounds at the same time on anything.

(Problems with mixing simultaneous audio streams was a real issue with ALSA years ago)

Apparently it's still an issue https://twitter.com/zeefreak/status/964162903392817156 …

I've never had an issue with this when running pulse over alsa, but I haven't looked into the internals of the interface, maybe pulse mixes the audio before sending to alsa? That's kinda neat though, curious why this has persisted as long as it has.

Pulse mixes everything. ALSA has dmix which can do the same but isn't enabled by default these days (because PA takes care of it). And PA usually has an ALSA plugin so *everything* should go to PA and get mixed by default.

If you have a really boneheaded legacy app that hardcodes the audio output device on ALSA or insists on direct hardware access then yeah, that will not work properly and will block other audio if there was nothing playing before.

Linux audio is such a mess. This is why I like FreeBSD. /dev/dsp is a virtual device that many processes can open, and a kernel thread mixes it. Simple as pie and it just F'ing works.

Can it switch dynamically between sound cards? Will plugging in external speakers re-route audio through the separate DAC channel? What about up/downmixing? Hotplugging HDMI to send audio to a TV? Network audio? Bluetooth? Ducking audio while on calls? PA does all of those.