[pulseaudio-discuss] Audible plop at beginning when using pcat-simple

[Sean Greenslade]

On Fri, Aug 27, 2021 at 04:57:07PM +0200, mindfsck wrote:
> I seem to be to silly for it:
> # sox in.wav -r 22050 out.wav resample
> sox FAIL formats: can't open input file `out.wav': No such file or directory
> 
> Of course there is no out.wav since that's what I want to create!

I would not bother with trying to change sample rates, that's very
unlikely to be the issue. Plus, a lot of sound cards only support 44.1
kHz and 48 kHz, so pulse would just have to resample it again on playback.

One thing you could try is making use of the buffering attributes in
pa_simple_new. Specifically, setting prebuf to a suitable value. There's
some helpful info in the buffer_attr docs page here:

https://www.freedesktop.org/software/pulseaudio/doxygen/structpa__buffer__attr.html

Another thing to check is if there are a couple of silent samples at the
beginning of the problematic wav files. If the first sample is non-zero,
that could potentially cause pops on playback.

--Sean