Thanks very much to everyone at the alsa project. With your help our live act setup finally works, and last week i was on stage with alsa. No need to carry around atari screens, no need to buy macintosh laptops, no need to use microsoft operating systems, no need to rely on buggy hardware midi sequencers. I only had to create a few lines of c code, and now i have two or more midi sequencers with a nice VGA UI running on a single laptop computer. The sequencers are controlled by midi keyboards, and they are fully beatsynced, even when using the skip/loop/tempo controls. That's nothing you can buy. Cubase/Logic wouldn't do this job. alsa does.
Stef(an). Hi Takashi! stef wrote: > > > > > > And if i add some more midi traffic, the sequencer queue slows down. I > > > > > > [...] Takashi Iwai wrote: > Ok, it looks like not directly related to scheduling of sequencer > but port access of MTPAV. > [...] > If it's mtpav hardware, especially midi output problem.. hmm.. > so far there is no check that the write buffer of mtpav (hardware) is > full or not. Possibly this may block the function somehow. So you think that it's possible that slow/buggy hardware/driver can slow down the queue tempo? It seems that the mtpav midi out driver is so slow that timer interrupts are getting lost, and the queue sometimes fails to advance the tick time. Possible? > > ...eight mtpav hardware ports, but with rtctimer 1024: same as with system > > timer > > ...eight mtpav hardware ports, but with rtctimer 128: nearly no slowdown > > Do you mean 1024Hz and 128Hz? > If so, it's interesting that slower interrupts prevent slowdown.. I meant the rtctimer_freq module parameter. And, yes, slower interrupts prevent queue slowdown. And it is also interesting that interrupt handling with the rtctimer is far more effective than with the system timer at the same frequency. > > When i come back next week, i definiteley start to reverse-engineer MOTU's > > parallel port protocol to fix the port routing problems of mtpav. > > Does Michael T. Mayers (who wrote card-mtpav) still exist? I was trying > > to contact him about a year ago, but no response. Do you maintain the code > > now? > > Well, i rewrote and cleaned up the code but i myself don't own the > hardware, so it's fairly difficult to maintain it correctly :-< Anyway, you managed to rewrite the code and it still works like the previous version. Congratulations! If i manage to fix the mtpav driver for proper port switching and performance, i'll submit a patch. If i fail at this task, you are the new owner of my MOTU Midi Express XT. Write a proper driver or sell it and remove mtpav from alsa. Maybe i do some VHDL coding and build my own alsa-only multiport midi interface hardware. Stef(an). _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
