[16:55] <SirSipe> Heyy! Not sure what would be the best place to ask this, but here we go: Does Jack (and/or Pipewire) have separate buffer for input and output? E.g. if I change buffer size from 128 to 256, is the roundtrip latency increase relative to 1x128 or 2x128? Apparently it's 2x in ASIO and Core Audio, but for ALSA/Jack/PipeWire I just can't find the answer.
[18:08] <Eickmeyer> SirSipe: No, it's all one master buffer.
[18:09] <Eickmeyer> Rather, it's a separate in/out buffer, but they must be the same size.
[18:10] <Eickmeyer> A definitive answer would best be found in #pipewire on OFTC.
[18:12] <SirSipe> I just did some roundtrip testing and it seems the roundrip latency actually correlates with 3x buffersize + C.
[18:13] <Eickmeyer> Seems reasonable, but I'd check with the folks in #pipewire on OFTC. The lead of PipeWire is there too.
[18:13] <SirSipe> nice, I will!
[18:14] <Eickmeyer> SirSipe: 3x buffersize makes sense for USB devices as 3x buffersize is required to keep with the 1ms timing of USB as USB clockspeed cannot be a fraction of a millisecond.
[18:15] <Eickmeyer> SirSipe: https://wiki.linuxaudio.org/wiki/list_of_jack_frame_period_settings_ideal_for_usb_interface#:~:text=Specify%20the%20number%20of%20frames%20between%20JACK%20process%28%29,yields%20higher%20latency%2C%20but%20makes%20xruns%20less%20likely.
[18:15] <Eickmeyer> Ignore that.
[18:15] <Eickmeyer> SirSipe: https://wiki.linuxaudio.org/wiki/list_of_jack_frame_period_settings_ideal_for_usb_interface
[18:19] <SirSipe> Oh, thanks! I'll read that
[18:23] <SirSipe> Damn, I didn't even realize there's a "periods" setting. I don't remember seeing that in Studio Controls but QJackCtl probably had that setting
[18:23] <SirSipe> Kind of sounds like my settings is 3
[18:26] <SirSipe> Actually there is and my setting is 2. Well that anyway explains 2/3 of the latency :P
[18:38] <SirSipe> According to http://linux-audio.com/jack/#specops periods only affect the output buffer. So that explains the 3x + C.