Re: [LAD] audio/midi app development

Excerpts from Gene Heskett's message of 2010-06-17 00:45:14 +0200:
> On Wednesday 16 June 2010, Patrick Shirkey wrote:
> >On 06/17/2010 04:52 AM, Ralf Mardorf wrote:
> >> Paul Davis wrote:
> >>> On Wed, Jun 16, 2010 at 2:30 PM, Ralf Mardorf
> >>>
> >>> <ralf.mardorf@alice-dsl.net> wrote:
> >>>> PS: Why not programming for savant syndrome musical gifted and 'fast'
> >>>> watching people too?
> >>>
> >>> the limits under discussion relate to monitor technology, not human
> >>> capabilities.
> >>
> >> I'm not a 'fast watching savant' ;) and even if the GUI is too slow, I
> >> won't care. I'm listening to music with my very good ears, but my bad
> >> eyes. No doubt, Linux is a good choice, but MIDI real-time could be
> >> better. For me the GUI is unimportant. BUT I prefer to do audio
> >> recordings using Linux, but MIDI recordings. It's a real pity, because
> >> MIDI would add some very cool features.
> >
> >This is only on your system right? I know a lot of people are working
> >with midi recording using linux tools.
> >
> >You see jitter at low latency but have you tried changing your hardware
> >or working with the driver developers to isolate and fix the bugs you
> >are seeing?
>
> One of the test tools that might be enlightening for the MIDI folks here, is
> the machine control program called emc. Because jitter is very important
> when feeding a stepper motor controller a steady heartbeat at high audio and
> somewhat above frequencies, the coders have developed a 'latency-test'
> script, which you run on one screen, then abuse the heck out of the machine
> doing other things, (browsing the web, moving windows around, compiling a
> kernel, whatever warms up the cpu) then come back half an hour or more later
> and read the average and worst case latencies as displayed in nanoseconds.
>
> Those are generally big figures so do the math and make milliseconds out of
> them.
>
> Emc when running stepper motors is fussier that all get out, and that tool
> just might point the finger at truly bad motherboard, or video hardware.
> FWIW, an nvida video card, can only be used in a machine running emc if the
> vesa driver is selected, all the others including nv, tie up the interrupts,
> sometimes for many milliseconds. For emc, that would equal a stalled motor
> and a wrecked part you were cutting at the time it stalled. Similar things
> can be said about the APCI of some motherboards. If that can't be fixed via
> a bios setting, toss the board. Via chipsets seem to be the most popular in
> this latter category.
>
> If its a complex part that you've already got several hours worth of carving
> & cutting tool wear into, that will only happen once, because whatever the
> culprit is, gets both found and a free airmail trip into the bin.
>
> What? Oh, I'll go back to lurking now. ;-)
>
> --
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> The policy is not to have policy. It works as well in kernel design as
> politics.
>
> - Alan Cox on linux-kernel

I fear something named simply 'emc' isn't easy to find around the net.

-- 
Regards,
Philipp
--
"Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan
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