[LAU] PS: [OT] Kernel 2.6.39.1

[Ralf Mardorf]

To avoid any discussion about what people are able to hear and what not,
here an example what people are able to draw from memory:

http://www.google.de/search?q=savant
+drawing&hl=en&biw=1152&bih=674&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ei=Kp_uTci0NISChQfh0-GYCQ&sqi=2&ved=0CDMQsAQ

Humans differ ;).

Some people might be unable to hear 1ms jitter, but it's a PITA for me
and my freakiness isn't limited to MIDI jitter or music. But I'm unable
to draw from memory :D, although gifted for drawing and other things.

I'm not audiophile or something similar :D.

On Tue, 2011-06-07 at 23:25 +0200, Ralf Mardorf wrote:
> On Tue, 2011-06-07 at 22:50 +0200, Robin Gareus wrote:
> > BTW. IIRC you should not use the -X... options for JACK-midi but rather
> > use a2j instead. AFAIK there were/are [timing?] issues with the built-in
> > JACK midi backends. (see Jeremy's workshop slides on how to launch a2j
> > using qjackctl's "Execute Script" option.)
> > 
> > HTH,
> > robin
> 
> Yesno! Perhaps it's better to avoid -Xseq, but I'm using JACK2 from svn
> with -Xalsarawmidi + a2jmidi_bridge to get a jitter free hw MIDI output
> of Qtractor's ALSA MIDI. I don't believe latency tests, but I believe
> what I hear and what I see for the waveforms. No jitter! Before Jack2
> from svn I experienced 1 - 3 ms jitter for hw MIDI (ALSA), depending to
> the used MIDI interface, I can't make music even with 1ms jitter, I'm
> able to hear this, see the following from jack devel list:
> 
> On Sat, 2011-06-04 at 03:54 +0200, Ralf Mardorf wrote:
> Similar good results as before :)
> > 
> > Cheers!
> > 
> > Ralf
> > 
> > Current Debian testing 64-bit
> > Two TerraTec EWX24/96 PCI
> > One RME HDSPe AIO     PCI express
> > 
> > # svn up /usr/src/jackmp
> > At revision 4447.
> > # chgrp audio /dev/hpet
> > # chmod g+rw /dev/hpet
> > # modprobe snd-hrtimer
> > 
> > $ uname -a
> > Linux debian 2.6.33.9-rt31 #1 SMP PREEMPT RT Thu Jun 2 12:42:46 CEST
> > 2011 x86_64 GNU/Linux
> > 
> > $ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
> > 'system:midi_capture_1', alias='system:1-1 HDSPM MIDI 1 1 in'
> > 'system:midi_capture_2', alias='system:1-2 HDSPM MIDI 2 1 in'
> > 'system:midi_capture_3', alias='system:2-1 TerraTec EWX24/96 MIDI 1
> in'
> > 'system:midi_capture_4', alias='system:3-1 TerraTec EWX24/96 MIDI 1
> in'
> > system:midi_playback_1', alias='system:1-1 HDSPM MIDI 1 1 out'
> > system:midi_playback_2', alias='system:1-2 HDSPM MIDI 2 1 out'
> > system:midi_playback_3', alias='system:2-1 TerraTec EWX24/96 MIDI 1
> out'
> > system:midi_playback_4', alias='system:3-1 TerraTec EWX24/96 MIDI 1
> out'
> > 
> > CPU frequency scaling performance
> > 
> > $ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:1-1 HDSPM MIDI 1 1
> > out" "system:1-1 HDSPM MIDI 1 1 in"
> > Waiting for connections ...
> > Waiting for test completion ...
> > 
> > Reported out-port latency: 5.33-5.33 ms (256-256 frames)
> > Reported in-port latency: 5.33-5.33 ms (256-256 frames)
> > Average latency: 12.23 ms (559.04 frames)
> > Lowest latency: 12.21 ms (558 frames)
> > Highest latency: 12.30 ms (562 frames)
> > Peak MIDI jitter: 0.09 ms (4 frames)
> > Average MIDI jitter: 0.01 ms (0.18 frames)
> > 
> > Jitter Plot:
> > 0.0 - 0.1 ms: 8192
> > 
> > Latency Plot:
> > 12.2 - 12.3 ms: 8192
> > 
> > Messages sent: 8192
> > Messages received: 8192
> > $ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:2-1 TerraTec
> EWX24/96
> > MIDI 1 out" "system:2-1 TerraTec EWX24/96 MIDI 1 in"
> > Waiting for connections ...
> > Waiting for test completion ...
> > 
> > Reported out-port latency: 5.33-5.33 ms (256-256 frames)
> > Reported in-port latency: 5.33-5.33 ms (256-256 frames)
> > Average latency: 12.23 ms (558.97 frames)
> > Lowest latency: 12.21 ms (558 frames)
> > Highest latency: 12.29 ms (562 frames)
> > Peak MIDI jitter: 0.09 ms (4 frames)
> > Average MIDI jitter: 0.00 ms (0.05 frames)
> > 
> > Jitter Plot:
> > 0.0 - 0.1 ms: 8192
> > 
> > Latency Plot:
> > 12.2 - 12.3 ms: 8192
> > 
> > Messages sent: 8192
> > Messages received: 8192
> > 
> > Old install, Edubuntu Maverick 32-bit on the same machine, just two
> > TerraTec EWX24/96 PCI, no PCI express
> > Test output copied from
> >
> http://lists.jackaudio.org/private.cgi/jack-devel-jackaudio.org/2011-April/007423.html
> > 
> > revision 4290
> > Linux edubuntu 2.6.33.7.2-rt30 #1 SMP PREEMPT RT Sun Jan 30 21:00:46
> CET
> > 2011 i686 GNU/Linux
> > 
> > $ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
> > 
> > $ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:TerraTec EWX24/96
> > MIDI out" "system:TerraTec EWX24/96 MIDI in"
> > Reported out-port latency: 5.33-5.33 ms (256-256 frames)
> > Reported in-port latency: 5.33-5.33 ms (256-256 frames)
> > Average latency: 11.06 ms (530.95 frames)
> > Lowest latency: 11.04 ms (530 frames)
> > Highest latency: 11.10 ms (533 frames)
> > Peak MIDI jitter: 0.06 ms (3 frames)
> > Average MIDI jitter: 0.00 ms (0.02 frames)
> > 
> > Jitter Plot:
> > 0.0 - 0.1 ms: 8192
> > 
> > Latency Plot:
> > 11.0 - 11.1 ms: 8189
> > 11.1 - 11.2 ms: 3
> > 
> > Messages sent: 8192
> > Messages received: 8192