Hi Miller.
You where right : using the -nosound flag increase the stability of MIDI timing : it run perfectly now even with a *very* high load of the midi output. I understand only now that the calculate audio checkbox is diferent than the -nosound flag.
For info : I've use the same patch on Win98 and Linux and the MIDI timming is better with Linux when the -nosound flag is *not* activated. when it is activated they are both good.
I will use 2 PD in the same time one with -nosound and one other with -nomidi. It will solve my problem.
many thanks.
dh.
De : Miller Puckette mpuckett@man104-1.ucsd.edu Envoyé : lundi 14 mai 2001 00:17 Objet : Re: [PD] midi syncro
Hmm,
I don't know the answers to any of this, except that, for the second question, notein just asks the OS to get the MIDI out as fast as possible. I'm surprised setting a small audiobuffer doesn't help. Another
possibility
is turning audio input or output (or both) off. MIDI is timed off audio transfers, so if teh OS is using a large block size for audio, MITI timing should suffer.
I'm going to work on this and see if I can improve it at all; I can
probably
get the timing jitter down to 5msec or so but it'll never be real pro quality until someone figures out how to use kernel-level time tagging on MIDI output...
cheers Miller
On Sun, May 13, 2001 at 10:12:58PM +0200, HENRY Damien wrote:
Hi Miller, Hi list.
When I send many midi event with noteon spaced like this :
! ! ! ! ! ! ! !
!
!
I get something like this :
! ! ! ! ! ! ! !
!
!
it's not a ramdom jiter, it's like an interference phenomena. Like if the regular rythme was modulated by an other. I've tried to generate an audio sound based on the same rythme, and this
one
is very regular : the jiter apear only on the midi output. I've play with -audiobuf without any good results... With 5ms, the midi rythme is 2 time slower than with 500ms or without using the -audiobuf
flag.
(I don't understand why)
- If too many event arrive in the same time to a noteon object, does PD
"decide" to schedule some for later ?
2 )Are MAXBUFFER and DEFBUFFER in the s_nt.c code file linked to midi timming ? Do you think that playing with this king of buffer can solve my problem
?
Thanks for your answer and help.
dh.