On Thu, September 19, 2013 7:42 pm, Fons Adriaensen wrote: > On Thu, Sep 19, 2013 at 06:46:11PM +1000, Patrick Shirkey wrote: > >> jack_system (in) -> pa_source (in) -> audacity (in) -> audacity (out) -> >> pa sink (out) -> jack_system (out) >> >> Audacity is run in pass through mode with internal latency set to 0. >> >> I would like to measure the round trip latency from jack_system (in) to >> jack_system (out) > > Easy using jack_delay. > > 1. Measure the round-trip latency of your sound card (with an > external analog loop). > Can I use jack_delay running on a second computer connected to the external i/o of the first computer to get this value? > 2. Measure > > jack_delay -> pa_source -> audacity -> pa_sink -> jack_delay. > Does this look reasonable? 1023.978 frames 21.333 ms total roundtrip latency extra loopback latency: 1023 frames use 511 for the backend arguments -I and -O 1023.976 frames 21.333 ms total roundtrip latency extra loopback latency: 1023 frames use 511 for the backend arguments -I and -O 1023.977 frames 21.333 ms total roundtrip latency extra loopback latency: 1023 frames use 511 for the backend arguments -I and -O > 3. If pa_source and pa_sink are a single Jack client (probably not), > subtract one period from the result of (2). > Can you explain that with the data above? > 4. Add the two values. > I would like to provide an app for this task. Do you think it would be worthwhile to extend jack_iodelay for this purpose? -- Patrick Shirkey Boost Hardware Ltd _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
