Re: [linux-audio-user] Keyboardist jitter detection?

From: Alexandre Ratchov <alex@email-addr-hidden>
Date: Mon Feb 12 2007 - 12:50:02 EET

On Sat, Feb 10, 2007 at 02:52:28PM +0100, Mario Lang wrote:
> Hi.
>
> I recently started to play a little keyboard. After guitar
> and traverse flute, the keyboard seemed the logical next step.
>
> I guess its totally normal to have a little problem with
> exactness. I wonder if there is a MIDI tool that
> could be used to measure my average jitter so that I could
> test myself and see if I improve?
>
> For instance, when playing BWV 846, it should be actually
> fairly easy measurable since that piece consists of mostly
> only 16th notes.
>
> Does such a program exist? I know the concept isn't that
> strange, Stanley Jordan told in a master session he
> was doing something like this with his MIDI-fitted guitar.
>

hi,

recent development snapshots (not releases) of midish display the
average jitter when a track is quantized. This isn't really a
feature, it's here mainly for debugging purposes. Once MIDI devices
are setup, you can use it as follows:

$ rmidish
send EOF character (control-D) to quit
1> nt mytrack # create a new track
2> r # record with metronome
press control-C to finish
^C
--interrupt--

3> sel 100 # select 100 first measures
4> n 16 # set quantization step to 16th note
5> q 100 # quantize the selection
track_quantize: fluct = 109, notes = 155, avg = 70% of a tick
6>

so the average jitter is 70% of a MIDI tick (there are 24 ticks in
a quarter note). Above commands could be embedded in a shell
script. Feel free to contact me if you encounter problems.

cheers,

-- Alexandre
Received on Mon Feb 12 16:15:01 2007

This archive was generated by hypermail 2.1.8 : Mon Feb 12 2007 - 16:15:01 EET