02-notein-object.py - How to use the Notein object.¶
This example shows how to use the Notein object to control audio processes with events received from a MIDI keyboard (virtual or not).
from pyo import * s = Server() s.setMidiInputDevice(99) # Open all input devices. s.boot() # Default arguments of the Notein object. # - 10 voices of polyphony, which means that this object will manage # 10 pitch/velocity streams simultaneously. # - scale=0 means that the pitch information will be MIDI numbers. # Use 1 for Hertz and 2 for transposition factors. # - first and last arguments are the lowest and highest MIDI notes # that this object will handle. This is useful to split the complete # range over multiple processes. # - channel is the MIDI channel this object will listen to. 0 means all # channels. # - The mul argument affects velocities, which are already normalized # between 0 and 1. notes = Notein(poly=10, scale=0, first=0, last=127, channel=0, mul=1) # User can show a keyboard widget to supply MIDI events. notes.keyboard() # Notein["pitch"] retrieves pitch streams. # Converts MIDI pitch to frequency in Hertz. freqs = MToF(notes["pitch"]) # Notein["velocity"] retrieves normalized velocity streams. # Applies a portamento on the velocity changes. amps = Port(notes["velocity"], risetime=0.005, falltime=0.5, mul=0.1) # Creates two groups of oscillators (10 per channel), slightly detuned. sigL = RCOsc(freq=freqs, sharp=0.5, mul=amps) sigR = RCOsc(freq=freqs * 1.003, sharp=0.5, mul=amps) # Mixes the 10 voices per channel to a single stream and send the # signals to the audio output. outL = sigL.mix(1).out() outR = sigR.mix(1).out(1) # Notein["trigon"] sends a trigger when a voice receive a noteon. # Notein["trigoff"] sends a trigger when a voice receive a noteoff. # These functions are called when Notein receives a MIDI note event. def noteon(voice): "Print pitch and velocity for noteon event." pit = int(notes["pitch"].get(all=True)[voice]) vel = int(notes["velocity"].get(all=True)[voice] * 127) print("Noteon: voice = %d, pitch = %d, velocity = %d" % (voice, pit, vel)) def noteoff(voice): "Print pitch and velocity for noteoff event." pit = int(notes["pitch"].get(all=True)[voice]) vel = int(notes["velocity"].get(all=True)[voice] * 127) print("Noteoff: voice = %d, pitch = %d, velocity = %d" % (voice, pit, vel)) # TrigFunc calls a function when it receives a trigger. Because notes["trigon"] # contains 10 streams, there will be 10 caller, each one with its own argument, # taken from the list of integers given at `arg` argument. tfon = TrigFunc(notes["trigon"], noteon, arg=list(range(10))) tfoff = TrigFunc(notes["trigoff"], noteoff, arg=list(range(10))) s.gui(locals())