3 Feb
2022
3 Feb
'22
12:07 a.m.
Le 02/02/2022 à 23:04, David Kastrup a écrit :
Ok, thanks a lot for this explanation :)
Yann Collette <ycollette.nospam(a)free.fr>
writes:
Just tried 128. I will try these 2 this
week-end.
Le 28/01/2022 à 16:40, ycollette.nospam(a)free.fr a
écrit :
192? 96? Nice, thanks for the hint. I will do some tests
next week.
----- Mail original -----
De: "David Kastrup" <dak(a)gnu.org>
À: "ycollette nospam" <ycollette.nospam(a)free.fr>
Cc: "Tim" <termtech(a)rogers.com>om>, linux-audio-user(a)lists.linuxaudio.org
Envoyé: Vendredi 28 Janvier 2022 16:37:52
Objet: Re: [LAU] Connect pipewire to running JACK server
ycollette.nospam(a)free.fr writes:
I just tested the "multiple of 3" rule and effectively, it worked.
With a buffer size of 256, I've got garbage and with the buffer of
size 128 it's fine. Can somebody share pipewire configuration files
for low latency audio with pw-jack ?
I am still struggling but maybe this is due to the audio USB interface
I've got: FocusRite 18i8.
It's maybe not overly relevant for your case but
I've had significantly
different experiences with, say, the Mackie Onyx Satellite and the ALSA
drivers by picking period sizes of 128 (which does not work without
periodic dropouts not marked as Xruns) and even something as low as 24
samples: apparently at least at 48kHz or 96kHz it is crucial to have the
period size divisable by 3. And if it is, very low latencies are
possible while if it isn't, you get garbage.
How did you find this rule ? Trial and errors ?
Yes and no. Some Windows ASIO drivers refused to do anything but that
for some Behringer USB card and worked with stuff as ridiculously low as
24. And if you try converting period sizes to millisecs, you need that
factor of 3.
The Opus Codec has as smallest standard size 120 samples @48kHz
(2.5msec) . Stuff like that. 48kHz needs that factor of 3 to map
nicely to millisecs.
It doesn't make a superb amount of sense to me I'll readily admit.
Maybe the actual rule is "avoid powers of 2" for some drivers and/or
hardware, and 3x2^n is about as far from a power of 2 as you can get.