Subject: Re: [linux-audio-dev] midi events in jack callback (was: Reborn)
From: Martijn Sipkema (msipkema_AT_sipkema-digital.com)
Date: Fri Aug 16 2002 - 18:49:31 EEST
> I find that for sending MIDI to an external device, "resolution = RTC
> Hz" works very well. It is a problem that a realtime audio thread
> 'suffocates' a RTC thread if low-latency is required, and only one
> processor available. It's very hard to find a clean solution in this
> case, but firm timers obviously do not address this particular
> problem.
User space MIDI scheduling should run at high rt priority. If scheduling
MIDI events is not done at a higher priority than the audio processing
then it will in general suffer jitter at the size of the audio interrupt
period.
Using the RTC is not necessary when using firm-timers.
Also, when doing hard real-time audio/MIDI, it is not possible to use
more than about 70% of the available CPU time and still get reliable
results.
Would a library for requesting the preferred scheduling policy and priority
for a certain task be a good idea to improve cooperation between
applications?
--martijn
This archive was generated by hypermail 2b28 : Fri Aug 16 2002 - 17:52:45 EEST