Midi Guitar - 6 Channel omni mode

oddson · 14 Mar 2007

See Dreamkeeper's post in this thread for an example of how to filter MIDI channels.

The MIDI coming out the right-hand-side will be events from the selected channel only.

BobTheDog · 14 Mar 2007

Hi,

Thanks for the info.

So I can split into 6 midi channels.

How would I then add pitchbend and create a poly signal?

Thanks for any help

Andy

oddson · 14 Mar 2007

I'm not sure if/how you can reassemble the data into a single poly-stream.

I'm not at my S|M machine right now, I'll have a look at it tonight.

oddson · 14 Mar 2007

@Bob - does the pitchbend data get sent on CC 1 (coarse) and CC 33 (fine)?

@Devs - can you just add multiple Poly streams (from six different MIDI2Poly components) together and they will become a usable poly stream?

stefan · 14 Mar 2007

Hm, I doubt it. Maybe you could write the six pitch bends into an array and extract the values from there using Float Array To Poly components. If you can work out how to create proper indices for each poly channel that is.

oddson · 14 Mar 2007

Thanks Stefan... I didn't think it would be that easy but I wanted to eliminate it as a solution before I tried anything too complex.

unkargherth · 15 Mar 2007

Mmmmm. Maybe manipulating thing in midi domain....

In short: filter out every midi channel, route it through a module that add de desired pictch bend IN MIDI MESSAGES. Then add up the six midi output into one MIDI to poly module

or i'm saying something stupid ?

BobTheDog · 15 Mar 2007

Hi Guys,

Thanks for your interest on this, it looks like it is not going to be straightforward!

Concerning pitchbend, I am not a midi expert but isn't pitchbend a 14 bit value seperate from CC messages.

I think it is a byte 0xEn where n is the midi channel followed by two bytes. Where the 14 bit value is the second byte shifted left 7 bits and ored with the first byte.

Cheers

Andy

BobTheDog · 15 Mar 2007

unkargherth wrote: Mmmmm. Maybe manipulating thing in midi domain....

In short: filter out every midi channel, route it through a module that add de desired pictch bend IN MIDI MESSAGES. Then add up the six midi output into one MIDI to poly module

or i'm saying something stupid ?

Hi,

This message apeared while I was posting my previous message.

This sounds exactly what I need, I have used this technique in Reaktor. Is it possible in SM?

Cheers

Andy

oddson · 15 Mar 2007

Pitch bend is not note specific, that's why the guitar controller uses 6 midi channels to give the disire result.

The question has definately peaked my interest. I'm still thinking about it.

oddson · 15 Mar 2007

oddson wrote: @Bob - does the pitchbend data get sent on CC 1 (coarse) and CC 33 (fine)?

Opps - i'm thinking of mod wheel... Pitchbend has it's own status byte so it's automatically two bytes* for data.

* well 7 bits for each of two bytes.

oddson · 15 Mar 2007

I've had a go at this but I have no idea if it works because I don't have the MIDI gear to test it out. guitarMidi.osm

Since each midi channel is monophonic (I assume) I figure I can use the pitch value as an ID within a code module and build a poly frequency stream by adding a pitch shift value and then converting to frequency.

stefan · 15 Mar 2007

Yes, each string is monophonic, but they overlap (a lot) in their pitch ranges. BUT.... As long as the guitarist doesn't play the same note on two strings (like an A on both the E string and on the A string), your method should work.

BobTheDog · 15 Mar 2007

Hi,

Thanks alot the patch, it is very good of you to help me out on this.

It works pretty well apart from playing the same note on two strings causes one of the notes to cut out.

I have tried to understand the patch but my abilitys in SM are not quite up to the required level

I think I understand the "MIDI guitar module" this seems to filter out the messages for a particular channel and output the pitch and pitchbend like : Pitch I = Midi note number Ptchbend f = ((pbend/8192) -1) * pitchbend range

So basically outputiing the pitchbend in semitones centered around 0 for no pitchbend.

Now to the code, here it gets a bit hazy in my mind I take it that the code sees if the note vale at p = each individual channels note and if so adds the bend value to shift. The output is then the P input plus the pitch shift, this leads to the problem when two midi notes P have the same value.

Am I anywhere near on this?

Cheers

Andy