Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Chris Cannam
Paul Davis: > frank (v.d.p) had the right idea back when he > started this Huh? Started what? Chris

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 18:40:20 -0500 Lee Revell <[EMAIL PROTECTED]> wrote: > The relative priorities of the JACK and soundcard IRQs really don't > matter because they never contend - one is woken up by the other. This is true for the audio only case. Imagine for now, that MIDI activity i shandled b

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Lee Revell
On Sat, 2005-12-31 at 00:31 +0100, Florian Schmidt wrote: > On Fri, 30 Dec 2005 20:54:53 +0100 > "Ralf Beck" <[EMAIL PROTECTED]> wrote: > > > Suppose a jack thread is running and your midiin device irq comes in but not > > through, > > because the device's irq thread has lower priority and does no

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 20:54:53 +0100 "Ralf Beck" <[EMAIL PROTECTED]> wrote: > Suppose a jack thread is running and your midiin device irq comes in but not > through, > because the device's irq thread has lower priority and does not get > scheduled! This is an interesting question: How is midi activ

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread fons adriaensen
On Fri, Dec 30, 2005 at 05:10:44PM -0500, Paul Davis wrote: > On Fri, 2005-12-30 at 22:27 +0100, Pedro Lopez-Cabanillas wrote: > > On Friday 30 December 2005 17:37, Werner Schweer wrote: > > > > > The ALSA seq api is from ancient time were no realtime threads were > > > available in linux. Only a

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Paul Davis
On Fri, 2005-12-30 at 22:27 +0100, Pedro Lopez-Cabanillas wrote: > On Friday 30 December 2005 17:37, Werner Schweer wrote: > > > The ALSA seq api is from ancient time were no realtime threads were > > available in linux. Only a kernel driver could provide usable > > midi timing. But with the intro

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Pedro Lopez-Cabanillas
On Friday 30 December 2005 17:37, Werner Schweer wrote: > The ALSA seq api is from ancient time were no realtime threads were > available in linux. Only a kernel driver could provide usable > midi timing. But with the introduction of RT threads the > ALSA seq api is obsolete IMHO. I don't agree w

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Ralf Beck
> higher priority thread can interrupt lower priority threads. What do > you gain if the soundcard can interrupt the jack thread? I believe > it does not matter. For proper midi handling, all threads, irq and user, related to midi should have a higher priority than that of the jack thread(s). Su

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Chris Cannam
Me: > I'll have to review the sequencer API and look at > adding a separate RT MIDI thread as an alternative Actually no, hang on a minute. First I want to know more about why the ALSA sequencer queue doesn't work better here. It's all very well saying it's irrelevant now that it's so easy

[linux-audio-dev] Olypus voice recorder - codec?

2005-12-30 Thread Dan Stromberg
Hi folks. This message does get into driver specifics to an extent, but I'm mostly coming to list for advice on how to find what "mystery codec" is being used. I've been putting some of the tiny bit of actual freetime I get during this winter holiday :), into trying to get a libusb-based driver

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Lee Revell
On Fri, 2005-12-30 at 15:17 +, Chris Cannam wrote: > - ALSA sequencer uses kernel timers by default and > of course they only run at 100 or 250Hz in many > kernels. > Not anymore, since 2.6.14 when the kernel developers decided to roll back HZ to 250 it uses the RTC by default. > - ALSA

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Lee Revell
On Fri, 2005-12-30 at 19:01 +0100, Werner Schweer wrote: > higher priority thread can interrupt lower priority threads. What do > you gain if the soundcard can interrupt the jack thread? I believe > it does not matter. > Interrupt routines on a well behaved system are using only some > microsecond

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Lee Revell
On Fri, 2005-12-30 at 18:25 +0100, Florian Schmidt wrote: > On Fri, 30 Dec 2005 15:17:04 + GMT > "Chris Cannam" <[EMAIL PROTECTED]> wrote: > > > - ALSA sequencer can sync to RTC, but the > > associated module (snd-rtctimer) appears to hang > > some kernels solid when loaded or used. I don'

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Werner Schweer
On Friday 30 December 2005 18:06, Florian Schmidt wrote: > On Fri, 30 Dec 2005 17:37:13 +0100 > > Werner Schweer <[EMAIL PROTECTED]> wrote: ... > > > Last note about RT-linux kernels: its not _that_ important. Its > > only a micro optimization. A normal recent kernel works pretty well. > > If your

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Chris Cannam
Florian Schmidt: > Yeah, i got a nice and juicy BUG in it (see below). So > this is what kills rosegarden regularly here when > run with RTC timing source. That'll be the chap. Mind you, I never saw the RTC- based timer measure significantly better than the system timer at 1000Hz. Although yo

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 15:17:04 + GMT "Chris Cannam" <[EMAIL PROTECTED]> wrote: > - ALSA sequencer can sync to RTC, but the > associated module (snd-rtctimer) appears to hang > some kernels solid when loaded or used. I don't have > much information about that, but I can probably find > out

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Chris Cannam
Florian Schmidt writes: > Here's example output with rosegarden producing a > supposedly steady stream of 16th notes at 120 bpm: > [...] Those results certainly are pretty poor. We do have a very similar test in the Rosegarden tree (the complainer test) but it doesn't stress the system quite

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread fons adriaensen
On Fri, Dec 30, 2005 at 11:54:56AM -0500, Paul Davis wrote: > you don't know the correct priority to use. i imagine an api along the > lines of: > > jack_create_thread (pthread_t*, void* (thread_function)(void*), > void* arg, int relative_to_jack); > > the last

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 11:54:56 -0500 Paul Davis <[EMAIL PROTECTED]> wrote: > you don't know the correct priority to use. i imagine an api along the > lines of: true. > > jack_create_thread (pthread_t*, void* (thread_function)(void*), > void* arg, int relative_to

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 17:37:13 +0100 Werner Schweer <[EMAIL PROTECTED]> wrote: > its right that MusE uses a RT midi thread to schedule midi > events. ALSA is used only to deliver (route) midi events. > I think this is the easiest possible solution and gives the app > the best control over timing.

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Paul Davis
On Fri, 2005-12-30 at 17:17 +0100, Florian Schmidt wrote: > On Fri, 30 Dec 2005 10:41:46 -0500 > Paul Davis <[EMAIL PROTECTED]> wrote: > > > several people have wanted JACK to export a thread create call that > > would take care of the RT-ness. that way, if you can run JACK with RT > > scheduling,

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Werner Schweer
On Friday 30 December 2005 16:17, Chris Cannam wrote: > Florian Schmidt writes: > > I further assume that the alsa seq event system > > is used > > This is true of Rosegarden, > > > and midi events are not queued > > for future delivery but always delivered immediately. > > but this isn't -- Rosega

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 10:41:46 -0500 Paul Davis <[EMAIL PROTECTED]> wrote: > several people have wanted JACK to export a thread create call that > would take care of the RT-ness. that way, if you can run JACK with RT > scheduling, you can run a MIDI thread too, with no extra steps. it would > also b

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 15:17:04 + GMT "Chris Cannam" <[EMAIL PROTECTED]> wrote: Hi Chris, > > and midi events are not queued > > for future delivery but always delivered immediately. > > but this isn't -- Rosegarden always queues events > from a non-RT thread and lets the ALSA sequencer > kern

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Paul Davis
> The biggest advantage of course is not having to run > an RT MIDI timing thread. My impression is that this > aspect of MusE (which does that, I think) causes > as many configuration problems for its users as using > ALSA sequencer queue timers does for Rosegarden's. > > Any more thoughts

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 16:03:44 +0100 Jens M Andreasen <[EMAIL PROTECTED]> wrote: > Flo! > > Is it important for the midi thread priority to be above the soundcard > IRQ, or is it enough to be above jackd? This is not 100% clear to me. I'd figure it should be above soundcard irq, too, just to be sa

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Chris Cannam
Florian Schmidt writes: > I further assume that the alsa seq event system > is used This is true of Rosegarden, > and midi events are not queued > for future delivery but always delivered immediately. but this isn't -- Rosegarden always queues events from a non-RT thread and lets the ALSA sequ

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Jens M Andreasen
Flo! Is it important for the midi thread priority to be above the soundcard IRQ, or is it enough to be above jackd? How will having several sound/midi cards fit into this scheme? (I have a builtin VIA chipset sound, a better quality Aureal PCI card and, for good measure, a USB control surface.)

Re: [linux-audio-dev] Audio/Midi system - RT prios..

2005-12-30 Thread Florian Schmidt
On Fri, 30 Dec 2005 01:52:10 +0100 Florian Schmidt <[EMAIL PROTECTED]> wrote: > On Fri, 30 Dec 2005 00:47:46 +0100 > Florian Schmidt <[EMAIL PROTECTED]> wrote: > > [snip] > > Hmm, > > forget this post :) I need to do some more testing first.. Ok, my synth was buggy (damn copy and paste). Now