[PD] midi syncro
damien_henry at libertysurf.fr
Sun May 13 22:12:58 CEST 2001
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)
1) 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
Do you think that playing with this king of buffer can solve my problem ?
Thanks for your answer and help.
> Hi dh,
> I've never measured MIDI timing stability in W98, but in general Pd
> time MIDI I/O carefully in either NT or Linux; output gets sent at the
> teh audio is COMPUTED, not when the audio actually appears on the output.
> To reduce MIDI jitter, you can reduce audio latency to the lowest amount
> Pd can stand. I think you should be able to get jitter down to 5-10 msec
> this way in W988 (it will be worse than this, probably, in NT or W2000).
> On Tue, May 08, 2001 at 11:07:04PM +0200, HENRY Damien wrote:
> > Dear list.
> > I'm running PD31 on Win98 (PIII 650 - 128mo Ram). Of course I envoy it
> > I'm creating rythms with PD : I use in the same time midi in to receive
> > parameters and midi out to send note coresponding to the rythme... Many
> > fun...
> > It's only midi processing so i turn audio calculation off.
> > My problem apear when i have an heavy load on midi : the rythme became
> > regular !!!
> > What can help me ?
> > 1) win NT instead of 98 ?
> > 2) linux ?
> > 3) PD32.6 instead of PD31 ?
> > 4) change the soundcard (SB live today)
> > 5) change the block size and overlap (I guess that midi is related to
> > block size)
> > 6) change the PC ?
> > 7) other idea ???
> > thanks.
> > dh.
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