[pulseaudio-discuss] PulseAudio Painfully Slow

[Alexander E. Patrakov]

14.07.2014 21:59, Laurențiu Nicola wrote:
> While I agree, I think it's only fair to say that both Windows and
> PulseAudio avoid the resampling if the source sample rate is the same as
> the configured one. In my distribution (Arch), /etc/pulse/daemon.conf
> has
>
> ; default-sample-rate = 44100
>
> which means it's the default. Many audio sources are 44.1 kHz, so they
> don't need resampling. It might be interesting to see what sample rate
> your the slow apps use and whether Pulse isn't configured to use 48000
> or something else.

PulseAudio has a per-sound-card notion of default and alternate sample 
rates, with the defaults settable from daemon.conf and in turn 
defaulting to 44.1 and 48 kHz. If the only sound being played has one of 
these rates, it is not resampled. Otherwise, PulseAudio tries to avoid 
resampling with scary rations. See the details in src/pulsecore/sink.c, 
function pa_sink_update_rate().

-- 
Alexander E. Patrakov