Heya!
So, as some of you might know in PA we extend the abilities of the hardware volume control in software. Meaning that if a hw mixer control only allows a limited range or granularity of a volume scale or does not distuingish between channels then PA will configure the hardware to the next higher available setting of the real volume it wants to achieve, and then attenuates the PCM stream to compensate for the rest.
This actually works quite well but there is a certain probelm with latency: i.e. the mixer setting will be applied at a slightly different time than the PCM attenuation.
Now the question I have is, how should I best deal with this? I currently assume that mixer volume changes are basically instantaneous when I call the respective function of ALSA. But are they really? How big is the latency at max? Do we need an API to query it?
Lennart