________________________________ From: katja katjavetter@gmail.com To: Jonathan Wilkes jancsika@yahoo.com Cc: "pd-dev@iem.at" pd-dev@iem.at Sent: Wednesday, May 29, 2013 1:12 PM Subject: Re: [PD-dev] jack dbus?
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I know only one way at the moment: routing Pulseaudio through JACK, equivalent to how Pd is routed through JACK. If this is called 'Pulseaudio on top of JACK', then 'yes'. The extra latency is because I need to set 2 periods of 512 samples (23 ms) for JACK's buffering to get audio without dropouts in this setup. In Pd I have it fixed at 15 ms. In practice there are more causes for latency, so I measure roundtrip latency in Pd with a sample-precise routine (see attached patch 'latency-tester2.pd'). Pd's 15 nominal ms is in practice 18 ms when routed directly via ALSA. Via the JACK + Pulseaudio setup it is a total of 50 ms in practice.
There's no other combination of frames/period and period/buffer you can use to get ca. 17-20ms latency without dropouts?
By the way this does of course not say anything about latency in Pulseaudio. Maybe there is a way to test that with a 'pulsified' application, for example Audacity.
That would be interesting to see.
-Jonathan