Altering Midi Events in Ruby.

[aefa]

Hello Everyone,
I'll try to say this as clear as possible. I'm splitting a midi event and catching it in ruby. What I need to do is change the midi note into a random note from a given note pool. So far I manage to pick the random note and place it into the output midi event but it doesn't respond to note off. Is there a fairly simple way to do this? I think my problem is that I can't hold the current note so to be able to stop it later...

Thank for any reply!

[Tronic]

FS - USER - GUIDE
pag. - 219 -

[aefa]

Thanks for the response Tronic, but I got all my variables in place. I split the midi event and work with the status, data1 and data2 values.
This is my logic:

prvNote = @oldNote # Here I try to catch the note that went out last.
if @status == 144
rndNote = @data1[rand(@data1.lenght)] # Here I pick a random note from the note pool to replace the incoming note
output 0, Midi.new 144,1,rndNote,@data2
prvNote = rndNote
output 1, prvNote # To catch it with oldNote
elsif @status == 128
output 0, Midi.new 128,1,prvNote,@data2 # Here I try to stop that last note
end

The problem is that it doesn't stop. it keeps playing.

[Tronic]

You have to schedule the output event with some relative duration time, to generate the NOTE off event.
see pag. -221- example

[aefa]

I forgot to mention that I'm quite the noob at this. I can see how the processing is being made but fail to see how it would help me send note off event. Can you give me an example related to a midi event? please...

[Tronic]

shedule events?
trig -> ruby process -> output trig happen only when the process is finisched
so in the event method you have some methods variables

Code: Select all

def event( input_index, value_at_index, time_at_trig)

   # so to schedule an event time that happen an bit later you have to use the method:
   # output [index of output], [value to send], [current_time + waiting_delay_time]
   #  [current_time + waiting_delay_time]
   #  -> schedule this event only when current_time is > of current_time+waiting_delay_time

   @note_length = 1 # in seconds
   output 0, @yourNoteoff_midi_object, time_at_trig + @note_length
end

[aefa]

Thank you very much Tronic. I'll try that and let you know!

[aefa]

Hi Trinic, I did try the way you suggested (though not exactly) I wanted to get the input note from a keyboard or piano roll and change it to a random one and it had to last as long as the key/p-r note was on. How did I fix it? I split the output midi event, got the data 1, fed it through a loop back and that took care of the problem. The random note generator event was generating a different note on the note-off that's why I couldn't catch it before.

Thank you very much for the insights!

[Tronic]

if I understand correctly, you want to simply replace the current note with a random note, right?

then the only thing to do is replace the data1 coming with that random, leaving intact the rest of the data.

Code: Select all

### assign to this var the first input connector
@midi_in = @ins[0]

### midi note pool container
### note the "||" operator that mean:
### initialize it only if is nil, after that it is not modified anymore
@midi_Pool ||= []  

### replace and add note random to the pool only if note_on
@random_note_range = (32..64)
@midi_Pool << @midi_in.data1 = rand(@random_note_range) if @midi_in.status == 144

### set to note_off the last played note in the pool
@midi_in.data1 = @midi_Pool.last if @midi_in.status == 128

### remove the released note from the pool
@midi_Pool.pop if @midi_in.status == 128

### output the current modified midi object to the output
output 0, @midi_in

EDIT: this work only with sequencially midi mote played and released

[Tronic]

This work with an correct midi pool order.
The code is for learning purpose, conditional used anyware...

Code: Select all

def init
@midi_pool = {};
@note_on = 144
@note_off = 128
end

def event i
@midi = @ins[0]
@rnd_note = rand(32..64)

@midi_pool[@midi.data1] = @rnd_note if @midi.status == @note_on && @midi_pool[@midi.data1].nil?
@note_released = @midi_pool.delete(@midi.data1) if @midi.status == @note_off

@midi.data1 = @midi_pool[@midi.data1] if @midi.status == @note_on && @note_released
@midi.data1 = @note_released if @midi.status == @note_off && @note_released
output 0, @midi if @note_released

watch [@midi_pool,@note_released]
end