annotate Syncopation models/readmidi.py @ 6:ac882f5e6a11

adding new bits for midi and music objects

# -*- coding: utf-8 -*-
"""
Created on Sat Mar 21 22:19:52 2015

@author: christopherh
"""

from midiparser import MidiFile, MidiTrack, DeltaTime, MidiEvent
#from RhythmParser import Bar

from MusicObjects import *





def readMidiFile(filename):
	""" open and read a MIDI file, return a MidiFile object """

	#create a midifile object, open and read a midi file
	midiFile = MidiFile()
	midiFile.open(filename, 'rb')
	midiFile.read()
	midiFile.close()

	return midiFile

def getBars(midiFile, trackindex=1):

	track = midiFile.tracks[trackindex] # ignore dummy track 0
	eventIdx = 0
	numNotes = 0

	noteonlist = []
	noteOnFound==True

	while noteOnFound==True:
		(noteOnIdx, noteOnDelta, noteOnFound) = self.findEvent(track, eventIdx, lambda e: e.type == 'NOTE_ON')
		noteEvent = track.events[noteOnIdx]
		eventIdx = noteOnIdx + 1
            	





def findEvent(track, eventStartIdx, lambdaExpr):
	'''
	From code by Csaba Sulyok:
	Finds MIDI event based on lambda expression, starting from a given index.
	Returns a tuple of the following 3 elements:
	1. event index where the lambda expression is true
	2. aggregate delta time from event start index until the found event
	3. flag whether or not any value was found, or we've reached the end of the event queue
	'''

	eventIdx = eventStartIdx
	deltaTime = 0
	while eventIdx < len(track.events) and not lambdaExpr(track.events[eventIdx]):
	    if track.events[eventIdx].type == 'DeltaTime':
	        deltaTime += track.events[eventIdx].time
	    eventIdx += 1

	success = eventIdx < len(track.events)
	return (eventIdx, deltaTime, success)