MIDI converter

  • Kash

    Kash - 2012-06-05

    I just discovered this feature today and I was absolutely bowled over by how full of pleasant surprises Rakarrack is. Major kudos to the devs for this amazing, feature-packed program - beats any commercial offering hands down.

    About the MIDI converter - it would be amazing if this feature could be developed further. Picture controlling samples and synths without learning keyboard, without having to invest in a MIDI guitar/guitar synth rig - simply plug in the guitar (now that I think about it, it could give MIDI capabilities to just about any instrument on earth) and one is good to go.

    I read up on the related 'MIDI output extension', and would like to draw the developers' attention to this blog post and video -
    Looks like it is not impossible. However, the plugin link there doesn't seem to work, and the blog appears to be defunct. Perhaps Rakarrack could implement this functionality in its MIDI converter? (Okay, that's a misnomer for the video in question, because it seems to not involve MIDI at all, though I don't understand how.)

    Thank you for your time, and thank you once more for this amazing program.

  • Josep Andreu

    Josep Andreu - 2012-06-05


    Unfortunatelly I dont have to much time to continue developing rakarrack rigth now, and sure other pitch detection algorithms are really better, also sure use more resources,  about the video is really interesting, we have a effect called Ring that you can use pitch detection to generate synth sounds, of course the synth on the ring effect is really simple, just you can mix differet waveforms.

    Maybe in a future I will have more time, I dont know and I can improve all, now is even impossible sorry.


  • Transmogrifox

    Transmogrifox - 2012-06-06

    I used aubio once to play around like that.   Actually you could use aubio's aubionotes jack program to improve Rakarrack's pitch estimation.  The signal chain would look like this:

    Guitar->Noise Gate->aubionotes->Rakarrack->MIDI to synth

    The noise gate is to prevent aubio from dribbling around with noise when the signal gets to a low level.  Aubionotes creates more pure tones, which are easier for Rakarrack's current pitch detection.  The rest explains itself.

    As for development of this feature, well, it is a matter of time.  I have been exploring the topic of efficient and effective pitch and beat detection, reading papers on the theory and such.  I have not yet time to implemented any code, so I don't know what will happen in the future.

    There are two possible ways to go about it:
    1) Pre-condition the signal to use the existing pitch detector (which will always be monophonic).
    2) Start more or less from scratch.

    Either way I have ideas but… well… time is the thing ;).  The down side of FOSS development is one has a hard time to make fast progress with 2 devs…but the beauty is, maybe somebody will help :).

  • Kash

    Kash - 2012-06-13

    Sorry for my late reply. Thank you for your input, holborn and transmogrifox. I shall try out Ring, and using aubionotes and rakarrack in conjunction.

  • Transmogrifox

    Transmogrifox - 2012-06-13

    I actually just reviewed the aubio web page and realized aubionotes outputs jack MIDI directly.  In this case, you input guitar to the noise gate, then the noise gate into aubionotes, then aubionotes into softsynth of choice.  Done.

    Of course, you could output the MIDI to the Ring effect in Rakarrack…which is actually a modulator, so IIRC you need to have another signal going to Rakarrack's input to hear any output.  I don't remember having implemented a synth mode (although this would be really easy).

    I hope that helps for now.  Perhaps aubio's libraries would be a faster track to providing polyphonic pitch detection in Rakarrack.

  • Kash

    Kash - 2012-09-05


    Just wished to update -

    I tried aubionotes. It consistently played everything a major 2nd lower than what I played, and moreover, there was *still* no polyphony. =\

    I have no words to describe how much an accurate polyphonic pitch-to-MIDI software could help my work, and in how many areas. I'm not a programmer, but could I not donate coins to Rakarrack to get this feature implemented? Even if it's too much for one guy alone (probably is), a fundraiser (Kickstarter?) perhaps? I'd rather spend on Rak's development than on a MIDI guitar, the benefits of a software solution notwithstanding.

    Please help.

  • Transmogrifox

    Transmogrifox - 2012-09-07

    This is a thing that interests me, so I would like to do it…but time is something I have not had in excess recently.  That said, it will take a long time before it is finished, if I was the only one to do it.  I think if you were to do a fundraiser type event it would be better to initiate a project to create a good free open source polyphonic pitch-to-MIDI C library…which then could be easily used by projects such as Rakarrack, Guitarix, and others yet to come ;)

    For now all I can say is it will probably happen eventually, but not very soon.  From what I have been reading about pitch and beat detection,  doing accurate polyphonic pitch-to-MIDI conversion will not be trivial. 

    As for aubio playing everything a major 2nd lower, that is easy to transpose with your synthesis engine, but polyphonic…is another thing.

  • ssj71

    ssj71 - 2012-11-09


    I don't know if you sare still interested, but it looks like aubio has a goal to implement polyphony. http://dev.aubio.org/wiki/Goals
    You could send some love their way I'm sure. I wish I had time to work on it. :)


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