[LAD] LV2 note2midi plugin

Cedric Roux sed at free.fr
Mon May 12 17:33:18 UTC 2014

On 05/10/2014 06:39 PM, Florian Paul Schmidt wrote:
> Hash: SHA1
> On 10.05.2014 00:18, Lucas Takejame wrote:
>> Hello guys, recently I assembled note2midi LV2 plugin based on the
>> ‘aubionotes’ from lib aubio's example folder. You can find it at
>> this link
>> https://github.com/portalmod/mod-utilities/tree/master/Note2Midi
>> and I'm hopping you guys could help me to improve this plugin so it
>> can be more reliable for using with guitar and bass. The majority
>> of the tests were made using pure sine waves. I barely know how the
>> algorithms ‘onset’ and ‘pitch’ detection works, that’s because I
>> don't know much more how the note2midi can be improved. I
>> appreciate if someone could give me some tips =)!
>> Att,
>> Lucas
> I would be interested in trying a different approach to this problem.
> Namely using machine learning. Would the guitar players on this list
> be willing to provide training data? I.e. audio files of you playing
> single notes with an additional text file describing the played
> pitches. A format like
> frame-number start 440
> frame-number end
> e.g. you have an audio clip at 1000hz sampling rate where an 440hz A
> starts on frame 500 (at 0.5 secs) that lasts to frame 2500 (so, 2 secs
> duration):
> 500 start 440
> 2500 end
> And so on.. Also for a usable guitar synthesizer one would maybe have
> to go a step further. The closer one is to the onset of the note the
> more uncertain the pitch is (loosely and much simplified speaking: for
> a low note it takes quite a while until even half a cycle has passed -
> during that time the pitch is very uncertain), so one approach would
> be to use a percussive sound for the start of the note (onset
> detection is easier than pitch detection I would figure) and then once
> the pitch is established fade to a second synthesis model that
> produces a clearly defined pitch.
> Mapping this to a midi stream introduces some loss of information, but
> could also be possible (e.g. two midi outs, one for the percussive
> onset detection and one for the (slower) pitch detection).
> I wanted to try this for a long time.. Maybe using decent machine
> learning and lots of training data one could even identify the pitch
> based on the characteristics of the very early signal from a note, but
> I'm not really certain about that.
> Sorry for hijacking your post and talking about several separate
> things at once, but maybe someone is interested in a project like this..
> Flo

quick recording, old guitar, old strings, cheap "studio", blabla.
It's standard tuning (eadgbe), more or less tuned (according to
The 6 strings are played from fret 0 to 12.
I let you find the freqs and the note start/end, it should not be
too hard with simple analysis algorithms (the ones you want to avoid).
I can record more, but as you can hear, it's not good quality...
(the URL will be valid until let's say 2014-06-30)

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