On 05/03/2012 10:43 AM, Joel Roth wrote: > On Thu, May 03, 2012 at 10:21:16AM +0200, Robin Gareus wrote: >> Capture latency in above message is a wrong. It was reported a while >> back: check jack-devel archive Dec 2010: > > Thanks > >> with jack2, there's also the difference of sync (jackd --sync .. -d alsa >> ...) vs. async mode. The latter adds 1 period of output latency. > > I'll need to read about this. --sync is listed in --help, > but not in the man page. http://www.grame.fr/~letz/jackdmp.html > I hope the difference shows up in get_jack_port_latency_range()! It does. The output latency is one period longer in async mode. >> see also: >> http://wiki.linuxaudio.org/wiki/jack_latency_tests > > And again. This is very helpful. > This wiki-page is a bit outdated (it's from before the new latency API was introduced) but item (2) under http://wiki.linuxaudio.org/wiki/jack_latency_tests#interpretation_and_analysis describes the same bug that you stumbled over. (1) was actually solved: The additional latency for USB devices comes from ALSA's USB driver implementation. Clemens explained the details in the same thread on jack-devel "Re: Differences in latency between USB and internal audio interfaces" December 9, 2010. ciao, robin _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
