[pulseaudio-discuss] ALSA or PulseAudio for low-latency voice?

[Philip Jägenstedt]

Hi PulseAudionauts,

I've been meaning to experiment a bit with low-latency voice codecs
and naturally want to add as little latency as possible to what is
imposed by the codec on both capture and playback. (My guess is that
the latency added would be between min(capture_latency,
playback_latency) and capture_latency+playback_latency, depending on
how well capture end and playback begin are synchronized.)

Q: Does it matters for latency if I program against ALSA or PulseAudio?

This is assuming a setup like on Ubuntu, where the default ALSA device
is using a PulseAudio backend. (Portability and code complexity may
favor one solution or the other, but that's not what I'm asking.)

Yesterday I would have guessed that anything that's possible with the
PulseAudio API should also be possible with the ALSA API, but after
reading http://0pointer.de/blog/projects/pulse-glitch-free.html I'm
not so sure. Unfortunately neither the FAQ or
http://0pointer.de/blog/projects/guide-to-sound-apis.html was enough
to clue me in.

Anything other must-know knowledge for someone curious about
low-latency audio who has previously mostly dabbled with GStreamer and
similar level APIs?

-- 
Philip Jägenstedt