On 01/14/2011 03:47 AM, Leigh Dyer wrote: > On 14/01/11 13:15, Jörn Nettingsmeier wrote: >> On 01/14/2011 12:59 AM, Leigh Dyer wrote: >> >>> Perhaps this is a question for Fons, but do you know if this plugin has >>> the same issue that stand-alone jconvolver has with JACK's freewheeling >>> mode? It'd be great to have Ardour exports continue to work as expected >>> while using this plugin. >> >> what is this issue, btw? i've seen the warning message countless times, >> but never found a problem with the audio after exporting from ardour in >> freewheeling mode... > > Fons has discussed it in the past on the list -- here's a link: > > http://lists.linuxaudio.org/pipermail/linux-audio-user/2009-December/065259.html cheers leigh. here's the relevant section of fons' explanation: > What is happening is this: zita convolver uses some > processing threads that effectively run with a period > that is a power-of-2 multiple of Jack's basic period. > They run on RT priorities just below the one of Jack's > process thread (-1 for for each doubling of the period). > The output of these threads must be ready when their > next period starts. > Zita-convolver checks this condition and will report > errors if these threads are too slow, but it will not > wait for them - you're not supposed to wait in Jack's > callback, and if your system does support the CPU load > for the given configuration they will be ready, even > with some safety margin. and that explains why it seems to work for me, even though i have moved to a quadcore system a while ago: my sessions tend to be biggish, and i usually bounce to the same partition that ardour reads the tracks from. hence, my export is i/o bound (not because of the raw bandwith i use, but because of excessive disk head movements). so it seems i've been lucky: since there is plenty of cpu left even when freewheeling "as fast as possible", zita's helper threads always finish on time. best, jörn _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
