Csound Python Score Real-time Performance Prototype

rtpysco.py

#!/usr/bin/python

import csnd6
import mido
import sys
from csd.pysco import PythonScore
from random import random


def note_to_freq(n):
    '''Convert MIDI note to frequency'''

    return 440.0 * 2 ** ((n - 69) / 12.0)
   
    
def flush_score():
    '''Send PySco data to Csound, and reset data'''

    output = '\n'.join(score._score_data)
    cs.ReadScore(output)
    print(output)
    score._score_data = []


def play_arp(amp, note):
    '''Arpeggiate note'''

    arp_notes = (0, 4, 7, 12)
    t = 0
    for a in arp_notes:
        score.i(1, t, 0.25, amp, note_to_freq(note + a))
        t += 0.25


# Setup PySco
score = PythonScore()
cue = score.cue

# Setup Csound API
cs = csnd6.Csound()
csPerf = csnd6.CsoundPerformanceThread(cs)
cs.SetOption('-odac')
cs.CompileOrc('''
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1
0dbfs = 1.0
''')
cs.Start()
csPerf.Play()
cs.CompileOrc('''
instr 1
    idur = p3
    iamp = p4
    ifreq = p5

    k1 line 1, idur, 0
    a1 oscils iamp, ifreq, 1
    out a1 * k1
endin
''')

# Play something in the beginning for maintain sanity
score.i('1 0 0.125 0.25 440');
flush_score()

# The rest is modified from mido receive.py example
if len(sys.argv) > 1:
    portname = sys.argv[1]
else:
    portname = None  # Use default port

try:
    with mido.open_input(portname) as port:
        print('Using {}'.format(port))
        print('Waiting for messages...')
        for m in port:
            print('Received {}'.format(m))
            if m.type is 'note_on' and m.velocity and m.note:
                play_arp(m.velocity / 127.0 * 0.5, m.note)
            flush_score()

except KeyboardInterrupt:
    pass