I was wondering how the 2.0 Proxy is envisioned to work. Aside from basic device pseudo handshakes, I wonder how values are scaled. Example, fader values, clock values, velocity, etc.
I understand that the receiving midi 1.0 device will only accept 7bit values but I wonder how the math will approach the conversion. Meaning is it truly just a matter of factoring / pairing down values from 14bit to 7bit.
I know from a previous post on scaling 7bit messsages. to 14 bit that :
If you log in to MIDI.org you should be able to find this document which defines the MIDI 2.0 range specification. You may need to create an account.
Note: In MIDI specifications we use hex representations because it can be easier to understand for development. For 32 bit values we use 0x00000000 to represent the smallest value, and 0xFFFFFFFF represents the largest value.
Steve Caldwell
Bome Customer Care
Also available for paid consulting services: bome@sniz.biz
Additionally , I understand the values are not one to one. For continuous controllers, I wonder if the there is a smoothing feature via proxy to closely emulate scaled values.
Hi Steve! I am not trying anything at the moment. I am curious about the protocol and a proxy. At some point I will want to test out building a Midi 2.0 proxy translation project out. For now there is now real need.
One of the challenges in the past using an Allen and Heath K2 controller was that the fader resolution is limited to 7bit. So volume, pitch adjustments were never good enough to be useful on these faders.
While I was reading up on the Midi 2.0 protocol, I was excited to see if there will be a smoothing feature which will more closely emulate a 14bit midi message via proxy using a 7bit controller.
I suspect there will be noticeable “stepping” for control messages like filter sweeps, ADSR envelop stage changes, or any controller value which is adjusted by 7bit messages. For example, it is not possible to precisely adjust pitch on a DJ deck (DJ software) with a k2 controller fader to beat match because of the resolution of the 7bit faders. A scaled or smoothing translation function doesn’t help in this scenario. However, I suspect it would be possible to use a “shift” function to go from granular to fine pitch adjustments. I’d have to do the math but for the purposes of the pitch example above, the 7bit fader could be used for a pitch adjustment of 8%, then once the bpm is roughly aligned, press a shift buttom to make finer adjustments within 1%. It is a silly and impractical example but it illustrates the point.
Anyway, by the time I dig into this, I am sure there will be a plethora of Midi 2.0 controllers. Besides, the DJ pitch example is not something I care for these days. It was just a thought which came to my mind when reading up on Midi 2.0.
My sights are more so set at the handshake features and how it may benefit my rig or if it really matters for what I do.
I am not clear yet on the additional features which I will employ via proxy… but I am excited to learn more.
Thanks for entertaining this thought! I am not looking for comments or feedback. I am sure you are busy but will of course welcome anything you have to share on the topic.
Hi, thanks for the clarification. There are still many details being worked out in the MIDI 2.0 spec. I’m sure there is some development going on by manufactures as well. I anticipate this will all come together at some point in time. I’m just not sure if it will be within the next year or longer. Being in the MIDI association may be a way to get an accelerated view of what is to come and also may help you influence some of the design detail.
As for now I believe there are some K2 controls that are relative and you can give them whatever resolution you want using a relative to absolute conversion translator within Bome MIDI Translator Pro . The question is really more whether the receiving MIDI equipment can handle either relative movement or higher resolution input. I think some of the newere Allen&Heath mixers already use 14 bit NRPN for various input parameters and not yet you convince that you would need more than that for a 100mm fader.
Steve Caldwell
Bome Customer Care
Also available for paid consulting services: bome@sniz.biz