christopher@45: # -*- coding: utf-8 -*-
christopher@45: """
christopher@45: Created on Sat Mar 21 22:19:52 2015
christopher@45: 
christopher@45: @author: christopherh
christopher@45: """
christopher@45: 
christopher@45: from midiparser import MidiFile, MidiTrack, DeltaTime, MidiEvent
christopher@45: #from RhythmParser import Bar
christopher@45: 
christopher@45: from music_objects import *
christopher@45: from basic_functions import *
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: def read_midi_file(filename):
christopher@45: 	""" open and read a MIDI file, return a MidiFile object """
christopher@45: 
christopher@45: 	#create a midifile object, open and read a midi file
christopher@45: 	midiFile = MidiFile()
christopher@45: 	midiFile.open(filename, 'rb')
christopher@45: 	midiFile.read()
christopher@45: 	midiFile.close()
christopher@45: 
christopher@45: 	return midiFile
christopher@45: 
christopher@45: # def get_bars(midiFile, trackindex=1):
christopher@45: # 	""" returns a list of bar objects from a MidiFile object """
christopher@45: 
christopher@45: # 	# select a track to extract (default = 1, ignoring dummy track 0)
christopher@45: # 	track = midiFile.tracks[trackindex] 
christopher@45: # 	eventIndex = 0
christopher@45: # 	numNotes = 0
christopher@45: 
christopher@45: # 	noteonlist = []
christopher@45: # 	noteOnFound==True
christopher@45: 
christopher@45: # 	while noteOnFound==True:
christopher@45: # 		(noteOnIndex, noteOnDelta, noteOnFound) = self.find_event(track, eventIndex, lambda e: e.type == 'NOTE_ON')
christopher@45: # 		noteEvent = track.events[noteOnIndex]
christopher@45: # 		eventIndex = noteOnIndex + 1
christopher@45:             	
christopher@45: 
christopher@45: #find_event(x.tracks[0], 0, lambda e: (e.type == 'NOTE_ON') | (e.type == 'KEY_SIGNATURE') | (e.type == "TIME_SIGNATURE"))
christopher@45: 
christopher@45: '''
christopher@45: 	#read midiFile
christopher@45: 	
christopher@45: 	
christopher@45: 
christopher@45: 	run through selected track getting notes out to build bars
christopher@45: 
christopher@45: '''
christopher@45: 	
christopher@45: 
christopher@45: 
christopher@45: def get_bars_from_midi(midiFile):
christopher@45: 
christopher@45: 	# couple of inner functions to tidy up getting the initial values of
christopher@45: 	# tempo and time signature
christopher@45: 	def get_initial_tempo(timeList):
christopher@45: 
christopher@45: 		tempo = None
christopher@45: 		i=0
christopher@45: 		# Find the initial time and tempo:
christopher@45: 		while(tempo == None and i<len(timeList)):
christopher@45: 			event = timeList[i]
christopher@45: 			i = i + 1
christopher@45: 			if event.type=="SET_TEMPO":
christopher@45: 		 		if tempo==None:
christopher@45: 					tempo = midi_event_to_qpm_tempo(event)
christopher@45: 
christopher@45: 		if tempo==None:
christopher@45: 			tempo = 120
christopher@45: 
christopher@45: 		return tempo
christopher@45: 
christopher@45: 	def get_initial_time_signature(timeList):
christopher@45: 
christopher@45: 		timesig = None
christopher@45: 		i=0
christopher@45: 		# Find the initial time and tempo:
christopher@45: 		while(timesig == None and i<len(timeList)):
christopher@45: 			event = timeList[i]
christopher@45: 			i = i + 1
christopher@45: 			if event.type=="TIME_SIGNATURE":
christopher@45: 				if timesig==None:
christopher@45: 					timesig = midi_event_to_time_signature(event)
christopher@45: 
christopher@45: 		if timesig==None:
christopher@45: 			timesig = TimeSignature("4/4")
christopher@45: 			
christopher@45: 		return timesig
christopher@45: 
christopher@45: 
christopher@45: 	def get_time_signature(timeList,barStartTime, barEndTime, currentTimeSignature = None):
christopher@45: 		
christopher@45: 		timesig = None
christopher@45: 		i=0
christopher@45: 		
christopher@45: 		while(i<len(timeList)):
christopher@45: 			# run through list until we find the most recent time signature
christopher@45: 			# before the end of the current bar
christopher@45: 			event = timeList[i]
christopher@45: 			i = i + 1
christopher@45: 			if event.time>=barEndTime:
christopher@45: 				break
christopher@45: 
christopher@45: 			if event.type=="TIME_SIGNATURE" and event.time>=barStartTime:
christopher@45: 				timesig = midi_event_to_time_signature(event)
christopher@45: 				event.type = "USED_TIME_SIGNATURE"
christopher@45: 	
christopher@45: 		if timesig==None:
christopher@45: 			if currentTimeSignature==None:
christopher@45: 				timesig = TimeSignature("4/4")
christopher@45: 			else:
christopher@45: 				timesig = currentTimeSignature
christopher@45: 
christopher@45: 		return timesig	
christopher@45: 
christopher@45: 	def get_tempo(timeList,barStartTime, barEndTime, currentTempo = None):
christopher@45: 		
christopher@45: 		tempo = None
christopher@45: 		i=0
christopher@45: 		# get first event:
christopher@45: 		while(i<len(timeList)):
christopher@45: 			# run through list until we find the most recent time signature
christopher@45: 			# before the end of the current bar
christopher@45: 			event = timeList[i]
christopher@45: 			i = i + 1
christopher@45: 			if event.time>=barEndTime:
christopher@45: 				break
christopher@45: 
christopher@45: 			# run through list until we find the most recent tempo
christopher@45: 			# before the end of the current bar
christopher@45: 			if event.type=="SET_TEMPO" and event.time>=barStartTime:
christopher@45: 				tempo = midi_event_to_qpm_tempo(event)
christopher@45: 				event.type = "USED_TEMPO"
christopher@45: 
christopher@45: 		if tempo==None:
christopher@45: 			if currentTempo==None:
christopher@45: 				tempo = 120
christopher@45: 			else:
christopher@45: 				tempo = currentTempo
christopher@45: 
christopher@45: 		return tempo
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 	# get initial time sig and tempo or use defaults
christopher@45: 	timeList = get_time_events(midiFile)
christopher@45: 
christopher@45: 	# get notes from the midi file (absolute start times from start of file)
christopher@45: 	notesList = get_notes_from_event_list(get_note_events(midiFile))
christopher@45: 	
christopher@45: 
christopher@45: 	# get initial tempo and time signature from time list
christopher@45: 	timesig = get_initial_time_signature(timeList)
christopher@45: 	tempo = get_initial_tempo(timeList)
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 	# ticks per quarter note:
christopher@45: 	ticksPerQuarter = midiFile.ticksPerQuarterNote
christopher@45: 	#calculate the initial length of a bar in ticks
christopher@45: 	barlength = calculate_bar_ticks(timesig.get_numerator(), timesig.get_denominator(), ticksPerQuarter)
christopher@45: 	# initialise time for start and end of current bar
christopher@45: 	barStartTime = 0
christopher@45: 	barEndTime = barlength
christopher@45: 	
christopher@45: 
christopher@45: 	# initialise bars list
christopher@45: 	bars = BarList()
christopher@45: 	noteIndex = 0
christopher@45: 
christopher@45: 	note = notesList[0]
christopher@45: 	# run through the notes list, chopping it into bars
christopher@45: 	while noteIndex<len(notesList):
christopher@45: 		#create a local note sequence to build a bar
christopher@45: 		currentNotes = NoteSequence()
christopher@45: 
christopher@45: 		timesig = get_time_signature(timeList,barStartTime, barEndTime, timesig)
christopher@45: 		tempo = get_tempo(timeList,barStartTime, barEndTime, tempo)
christopher@45: 		
christopher@45: 
christopher@45: 		#find all the notes in the current bar
christopher@45: 		while(note.startTime<barEndTime):
christopher@45: 			#make note start time relative to current bar
christopher@45: 			note.startTime = note.startTime - barStartTime
christopher@45: 			#add note to current bar note sequence
christopher@45: 			currentNotes.append(note)
christopher@45: 			noteIndex = noteIndex + 1
christopher@45: 			if noteIndex<len(notesList):
christopher@45: 				note = notesList[noteIndex]
christopher@45: 			else:
christopher@45: 				break
christopher@45: 
christopher@45: 		# create a new bar from the current notes and add it to the list of bars
christopher@45: 		bars.append(Bar(currentNotes, timesig, ticksPerQuarter, tempo))
christopher@45: 
christopher@45: 		barStartTime = barEndTime
christopher@45: 
christopher@45: 		barEndTime = barEndTime + barlength
christopher@45: 
christopher@45: 	return bars
christopher@45: 
christopher@45: 		
christopher@45: #get note objects from a list of note midi events
christopher@45: def get_notes_from_event_list(noteEventList):
christopher@45: 	noteslist = NoteSequence()
christopher@45: 
christopher@45: 	index = 0
christopher@45: 	
christopher@45: 	#while not at the end of the list of note events
christopher@45: 	while index<len(noteEventList):
christopher@45: 		#get next event from list
christopher@45: 		event = noteEventList[index]
christopher@45: 		index = index + 1
christopher@45: 		#if we've found the start of a note, search for the corresponding end event
christopher@45: 		if event.type=="NOTE_ON" and event.velocity!=0:
christopher@45: 			localindex = index
christopher@45: 			
christopher@45: 			#find corresponding end event
christopher@45: 			while localindex<len(noteEventList):
christopher@45: 				endEvent = noteEventList[localindex]
christopher@45: 				#if its the same note and it's an end event
christopher@45: 				if endEvent.pitch==event.pitch and (endEvent.type=="NOTE_OFF" or (endEvent.type=="NOTE_ON" and endEvent.velocity==0)):
christopher@45: 					#make a note
christopher@45: 					note = Note(event.time,endEvent.time-event.time,event.velocity)
christopher@45: 					#alter the type of this end event so it can't be linked to another note on
christopher@45: 					endEvent.type = "DUMMY"
christopher@45: 					#add the note to the list
christopher@45: 					noteslist.append(note)
christopher@45: 					#found the end of the note so break out of the local loop
christopher@45: 					break
christopher@45: 
christopher@45: 	return noteslist
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: 
christopher@45: def get_note_events(midiFile, trackNumber = None):
christopher@45: 	"""
christopher@45: 	Gets all note on and note off events from a midifile.
christopher@45: 
christopher@45: 	If trackNumber is not specified, the function will check the file format
christopher@45: 	and pick either track 0 for a type 0 (single track format) or track 1 
christopher@45: 	for a type 1 or 2 (multi-track) midi file.
christopher@45: 
christopher@45: 	"""
christopher@45: 
christopher@45: 	if trackNumber==None:
christopher@45: 		if midiFile.format==0:
christopher@45: 			trackNumber=0
christopher@45: 		else:
christopher@45: 			trackNumber=1
christopher@45: 
christopher@45: 	return get_events_of_type(midiFile, trackNumber, lambda e: (e.type == 'NOTE_ON') | (e.type == "NOTE_OFF") )
christopher@45: 	
christopher@45: 
christopher@45: 
christopher@45: def get_time_events(midiFile):
christopher@45: 	"""
christopher@45: 	Gets time signature and tempo events from a MIDI file (MIDI format 0 
christopher@45: 	or format 1) and returns a list of those events and their associated 
christopher@45: 	absolute start times.  If no time signature or tempo are specified then
christopher@45: 	defaults of 4/4 and 120QPM are assumed.
christopher@45: 
christopher@45: 	From the MIDI file specification:
christopher@45: 
christopher@45: 	"All MIDI Files should specify tempo and time signature. If they don't, 
christopher@45: 	the time signature is assumed to be 4/4, and the tempo 120 beats per 
christopher@45: 	minute. In format 0, these meta-events should occur at least at the 
christopher@45: 	beginning of the single multi-channel track. In format 1, these meta-events
christopher@45: 	should be contained in the first track. In format 2, each of the temporally
christopher@45: 	independent patterns should contain at least initial time signature and 
christopher@45: 	tempo information."
christopher@45: 
christopher@45: 	"""
christopher@45: 	return get_events_of_type(midiFile, 0, lambda e: (e.type == 'SET_TEMPO') | (e.type == "TIME_SIGNATURE") )
christopher@45: 	
christopher@45: 
christopher@45: def get_events_of_type(midiFile, trackIndex, lambdaEventType):
christopher@45: 	"""
christopher@45: 	Filters the events in a midi track that are selected by the 
christopher@45: 	function object lambdaEventType e.g. lambda e: (e.type == 'NOTE_ON')
christopher@45: 	Return a list containing the relevant events with appropriate 
christopher@45: 	delta times between them 
christopher@45: 	"""
christopher@45: 	
christopher@45: 	track = midiFile.tracks[trackIndex] 
christopher@45: 	eventIndex = 0
christopher@45: 	#	numTimeEvents = 0
christopher@45: 
christopher@45: 	localEventList  = []
christopher@45: 	localEventFound = True
christopher@45: 	#accumulatedTime = 0
christopher@45: 
christopher@45: 	while localEventFound==True:
christopher@45: 		#find the next time event from the track:
christopher@45: 		(localEventIndex, localEventDelta, localEventFound) = find_event(track, eventIndex, lambdaEventType)
christopher@45: 
christopher@45: 		if localEventFound==True:
christopher@45: 			#get the time event object out of the track
christopher@45: 			localEvent = track.events[localEventIndex]
christopher@45: 
christopher@45: 			#update the start event to search from
christopher@45: 			eventIndex = localEventIndex + 1
christopher@45: 
christopher@45: 			#calculate the absolute start time of the time event
christopher@45: 			#accumulatedTime = accumulatedTime + localEventDelta
christopher@45: 
christopher@45: 			localEventList.append(localEvent)
christopher@45: 
christopher@45: 	return localEventList
christopher@45: 
christopher@45: 
christopher@45: def midi_event_to_time_signature(midiTimeSignatureEvent):
christopher@45: 	"""
christopher@45: 	Extract the numerator and denominator from a midi time signature
christopher@45: 	event and return a TimeSignature music object.  Ignore clocks per
christopher@45: 	quarternote and  32nds per quarternote elements since these are
christopher@45: 	only for sequencer metronome settings which we won't use here.
christopher@45: 	"""
christopher@45: 	if midiTimeSignatureEvent.type!="TIME_SIGNATURE":
christopher@45: 		print "Error in midi_event_to_time_signature(),  event must be a midi time signature type"
christopher@45: 		return None
christopher@45: 	else:
christopher@45: 		num = ord(midiTimeSignatureEvent.data[0])
christopher@45: 		denom = 2**ord(midiTimeSignatureEvent.data[1])
christopher@45: 		return TimeSignature("%d/%d" % (num, denom))
christopher@45: 	
christopher@45: 
christopher@45: def midi_event_to_qpm_tempo(midiTempoEvent):
christopher@45: 	"""
christopher@45: 	Extract the tempo in QPM from a midi SET_TEMPO event
christopher@45: 	"""
christopher@45: 	if midiTempoEvent.type!="SET_TEMPO":
christopher@45: 		print "Error in midi_event_to_qpm_tempo(),  event must be a midi tempo event"
christopher@45: 		return None
christopher@45: 	else:
christopher@45: 		# tempo is stored as microseconds per quarter note
christopher@45: 		# in three bytes which we can extract as three ints:
christopher@45: 		values = map(ord, midiTempoEvent.data)
christopher@45: 		# first byte multiplied by 2^16, second 2^8 and third is normal units
christopher@45: 		# giving microseconds per quarter
christopher@45: 		microsecondsPerQuarter = values[0]*2**16 + values[1]*2**8 + values[2]
christopher@45: 
christopher@45: 		# to calculate QPM, 1 minute = 60million microseconds
christopher@45: 		# so divide 60million by micros per quarter:
christopher@45: 		return 60000000/microsecondsPerQuarter
christopher@45: 
christopher@45: def find_event(track, eventStartIndex, lambdaExpr):
christopher@45: 	'''
christopher@45: 	From code by Csaba Sulyok:
christopher@45: 	Finds MIDI event based on lambda expression, starting from a given index.
christopher@45: 	Returns a tuple of the following 3 elements:
christopher@45: 	1. event index where the lambda expression is true
christopher@45: 	2. aggregate delta time from event start index until the found event
christopher@45: 	3. flag whether or not any value was found, or we've reached the end of the event queue
christopher@45: 	'''
christopher@45: 
christopher@45: 	eventIndex = eventStartIndex
christopher@45: 	deltaTime = 0
christopher@45: 	while eventIndex < len(track.events) and not lambdaExpr(track.events[eventIndex]):
christopher@45: 	    if track.events[eventIndex].type == 'DeltaTime':
christopher@45: 	        deltaTime += track.events[eventIndex].time
christopher@45: 	    eventIndex += 1
christopher@45: 
christopher@45: 	success = eventIndex < len(track.events)
christopher@45: 	return (eventIndex, deltaTime, success)
christopher@45: 
christopher@45: