# ----------------------------------------------------------------------------- # Name: MidiFile.py # Purpose: MIDI file manipulation utilities # # Author: Mark Conway Wirt # # Created: 2008/04/17 # Copyright: (c) 2009-2016 Mark Conway Wirt # License: Please see License.txt for the terms under which this # software is distributed. # ----------------------------------------------------------------------------- from __future__ import division, print_function import math import struct import warnings __version__ = 'HEAD' # TICKSPERQUARTERNOTE is the number of "ticks" (time measurement in the MIDI file) that # corresponds to one quarter note. This number is somewhat arbitrary, but should # be chosen to provide adequate temporal resolution. TICKSPERQUARTERNOTE = 960 controllerEventTypes = {'pan': 0x0a} # Define some constants MAJOR = 0 MINOR = 1 SHARPS = 1 FLATS = -1 __all__ = ['MIDIFile', 'MAJOR', 'MINOR', 'SHARPS', 'FLATS'] class GenericEvent(object): ''' The event class from which specific events are derived ''' evtname = None sec_sort_order = 0 def __init__(self, tick, insertion_order): self.tick = tick self.insertion_order = insertion_order def __eq__(self, other): ''' Equality operator. In the processing of the event list, we have need to remove duplicates. To do this we rely on the fact that the classes are hashable, and must therefore have an equality operator (__hash__() and __eq__() must both be defined). Some derived classes will need to override and consider their specific attributes in the comparison. ''' return (self.evtname == other.evtname and self.tick == other.tick) def __hash__(self): ''' Return a hash code for the object. This is needed in order to allow GenericObject classes to be used as the key in a dict or set. duplicate objects are removed from the event list by storing all the objects in a set, and then reconstructing the list from the set. The only real requirement for the algorithm is that the hash of equal objects must be equal. There is probably great opportunity for improvements in the hashing function. ''' # Robert Jenkin's 32 bit hash. a = int(self.tick) a = (a + 0x7ed55d16) + (a << 12) a = (a ^ 0xc761c23c) ^ (a >> 19) a = (a + 0x165667b1) + (a << 5) a = (a + 0xd3a2646c) ^ (a << 9) a = (a + 0xfd7046c5) + (a << 3) a = (a ^ 0xb55a4f09) ^ (a >> 16) return a class NoteOn(GenericEvent): ''' A class that encapsulates a note ''' evtname = 'NoteOn' midi_status = 0x90 # 0x9x is Note On sec_sort_order = 3 def __init__(self, channel, pitch, tick, duration, volume, annotation=None, insertion_order=0): self.pitch = pitch self.duration = duration self.volume = volume self.channel = channel self.annotation = annotation super(NoteOn, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.evtname == other.evtname and self.tick == other.tick and self.pitch == other.pitch and self.channel == other.channel) # In Python 3, a class which overrides __eq__ also needs to provide __hash__, # because in Python 3 parent __hash__ is not inherited. __hash__ = GenericEvent.__hash__ def __str__(self): return 'NoteOn %d at tick %d duration %d ch %d vel %d' % ( self.pitch, self.tick, self.duration, self.channel, self.volume) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', self.pitch) midibytes += struct.pack('>B', self.volume) return midibytes class NoteOff (GenericEvent): ''' A class that encapsulates a Note Off event ''' evtname = 'NoteOff' midi_status = 0x80 # 0x8x is Note Off sec_sort_order = 2 # must be less than that of NoteOn # If two events happen at the same time, the secondary sort key is # ``sec_sort_order``. Thus a class of events can be processed earlier than # another. One place this is used in the code is to make sure that note # off events are processed before note on events. def __init__(self, channel, pitch, tick, volume, annotation=None, insertion_order=0): self.pitch = pitch self.volume = volume self.channel = channel self.annotation = annotation super(NoteOff, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.evtname == other.evtname and self.tick == other.tick and self.pitch == other.pitch and self.channel == other.channel) __hash__ = GenericEvent.__hash__ def __str__(self): return 'NoteOff %d at tick %d ch %d vel %d' % ( self.pitch, self.tick, self.channel, self.volume) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', self.pitch) midibytes += struct.pack('>B', self.volume) return midibytes class Tempo(GenericEvent): ''' A class that encapsulates a tempo meta-event ''' evtname = 'Tempo' sec_sort_order = 3 def __init__(self, tick, tempo, insertion_order=0): self.tempo = int(60000000 / tempo) super(Tempo, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.evtname == other.evtname and self.tick == other.tick and self.tempo == other.tempo) __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ # Standard MIDI File Format says: # # FF 51 03 tttttt Set Tempo (in microseconds per MIDI quarter-note) # This event indicates a tempo change. Another way of putting # "microseconds per quarter-note" is "24ths of a microsecond per MIDI # clock". Representing tempos as time per beat instead of beat per time # allows absolutely exact long-term synchronisation with a time-based # sync protocol such as SMPTE time code or MIDI time code. The amount # of accuracy provided by this tempo resolution allows a four-minute # piece at 120 beats per minute to be accurate within 500 usec at the # end of the piece. Ideally, these events should only occur where MIDI # clocks would be located -- this convention is intended to guarantee, # or at least increase the likelihood, of compatibility with other # synchronisation devices so that a time signature/tempo map stored in # this format may easily be transferred to another device. # # Six identical lower-case letters such as tttttt refer to a 24-bit value, stored # most-significant-byte first. The notation len refers to the midibytes = b"" code = 0xFF subcode = 0x51 fourbite = struct.pack('>L', self.tempo) # big-endian uint32 threebite = fourbite[1:4] # Just discard the MSB varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', subcode) midibytes += struct.pack('>B', 0x03) # length in bytes of 24-bit tempo midibytes += threebite return midibytes class Copyright(GenericEvent): ''' A class that encapsulates a copyright event ''' evtname = 'Copyright' sec_sort_order = 1 def __init__(self, tick, notice, insertion_order=0): self.notice = notice.encode("ISO-8859-1") super(Copyright, self).__init__(tick, insertion_order) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ # Standard MIDI File Format says: # # FF 02 len text Copyright Notice # Contains a copyright notice as printable ASCII text. The notice should # contain the characters (C), the year of the copyright, and the owner # of the copyright. If several pieces of music are in the same MIDI # File, all of the copyright notices should be placed together in this # event so that it will be at the beginning of the file. This event # should be the first event in the track chunk, at tick 0. midibytes = b"" code = 0xFF subcode = 0x02 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', subcode) payloadLength = len(self.notice) payloadLengthVar = writeVarLength(payloadLength) for i in payloadLengthVar: midibytes += struct.pack("b", i) midibytes += self.notice return midibytes class Text(GenericEvent): ''' A class that encapsulates a text event ''' evtname = 'Text' sec_sort_order = 1 def __init__(self, tick, text, insertion_order=0): self.text = text.encode("ISO-8859-1") super(Text, self).__init__(tick, insertion_order) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = 0xFF subcode = 0x01 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', subcode) payloadLength = len(self.text) payloadLengthVar = writeVarLength(payloadLength) for i in payloadLengthVar: midibytes += struct.pack("B", i) midibytes += self.text return midibytes class KeySignature(GenericEvent): ''' A class that encapsulates a text event ''' evtname = 'KeySignature' sec_sort_order = 1 def __init__(self, tick, accidentals, accidental_type, mode, insertion_order=0): self.accidentals = accidentals self.accidental_type = accidental_type self.mode = mode super(KeySignature, self).__init__(tick, insertion_order) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = 0xFF subcode = 0x59 event_subtype = 0x02 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', subcode) midibytes += struct.pack('>B', event_subtype) midibytes += struct.pack('>b', self.accidentals * self.accidental_type) midibytes += struct.pack('>B', self.mode) return midibytes class ProgramChange(GenericEvent): ''' A class that encapsulates a program change event. ''' evtname = 'ProgramChange' midi_status = 0xc0 # 0xcx is Program Change sec_sort_order = 1 def __init__(self, channel, tick, programNumber, insertion_order=0): self.programNumber = programNumber self.channel = channel super(ProgramChange, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.evtname == other.evtname and self.tick == other.tick and self.programNumber == other.programNumber and self.channel == other.channel) __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel varTime = writeVarLength(self.tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', self.programNumber) return midibytes class SysExEvent(GenericEvent): ''' A class that encapsulates a System Exclusive event. ''' evtname = 'SysEx' # doesn't match class name like most others sec_sort_order = 1 def __init__(self, tick, manID, payload, insertion_order=0): self.manID = manID self.payload = payload super(SysExEvent, self).__init__(tick, insertion_order) def __eq__(self, other): return False __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = 0xF0 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) payloadLength = writeVarLength(len(self.payload) + 2) for lenByte in payloadLength: midibytes += struct.pack('>B', lenByte) midibytes += struct.pack('>B', self.manID) midibytes += self.payload midibytes += struct.pack('>B', 0xF7) return midibytes class UniversalSysExEvent(GenericEvent): ''' A class that encapsulates a Universal System Exclusive event. ''' evtname = 'UniversalSysEx' # doesn't match class name like most others sec_sort_order = 1 def __init__(self, tick, realTime, sysExChannel, code, subcode, payload, insertion_order=0): self.realTime = realTime self.sysExChannel = sysExChannel self.code = code self.subcode = subcode self.payload = payload super(UniversalSysExEvent, self).__init__(tick, insertion_order) def __eq__(self, other): return False __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = 0xF0 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) # Do we need to add a length? payloadLength = writeVarLength(len(self.payload) + 5) for lenByte in payloadLength: midibytes += struct.pack('>B', lenByte) if self.realTime: midibytes += struct.pack('>B', 0x7F) else: midibytes += struct.pack('>B', 0x7E) midibytes += struct.pack('>B', self.sysExChannel) midibytes += struct.pack('>B', self.code) midibytes += struct.pack('>B', self.subcode) midibytes += self.payload midibytes += struct.pack('>B', 0xF7) return midibytes class ControllerEvent(GenericEvent): ''' A class that encapsulates a program change event. ''' evtname = 'ControllerEvent' midi_status = 0xB0 # 0xBx is Control Change sec_sort_order = 1 def __init__(self, channel, tick, controller_number, parameter, insertion_order=0): self.parameter = parameter self.channel = channel self.controller_number = controller_number super(ControllerEvent, self).__init__(tick, insertion_order) def __eq__(self, other): return False __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', self.controller_number) midibytes += struct.pack('>B', self.parameter) return midibytes class ChannelPressureEvent(GenericEvent): ''' A class that encapsulates a Channel Pressure (Aftertouch) event. ''' evtname = 'ChannelPressure' midi_status = 0xD0 # 0xDx is Channel Pressure (Aftertouch) sec_sort_order = 1 def __init__(self, channel, tick, pressure_value, insertion_order=0): self.channel = channel self.pressure_value = pressure_value super(ChannelPressureEvent, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.__class__.__name__ == other.__class__.__name__ and self.tick == other.tick and self.pressure_value == other.pressure_value and self.channel == other.channel) __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel vartick = writeVarLength(self.tick - previous_event_tick) for x in vartick: midibytes += struct.pack('>B', x) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', self.pressure_value) return midibytes class PitchWheelEvent(GenericEvent): ''' A class that encapsulates a pitch wheel change event. ''' evtname = 'PitchWheelEvent' midi_status = 0xE0 # 0xEx is Pitch Wheel Change sec_sort_order = 1 def __init__(self, channel, tick, pitch_wheel_value, insertion_order=0): self.channel = channel self.pitch_wheel_value = pitch_wheel_value super(PitchWheelEvent, self).__init__(tick, insertion_order) def __eq__(self, other): return False __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = self.midi_status | self.channel varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes = midibytes + struct.pack('>B', timeByte) MSB = (self.pitch_wheel_value + 8192) >> 7 LSB = (self.pitch_wheel_value + 8192) & 0x7F midibytes = midibytes + struct.pack('>B', code) midibytes = midibytes + struct.pack('>B', LSB) midibytes = midibytes + struct.pack('>B', MSB) return midibytes class TrackName(GenericEvent): ''' A class that encapsulates a program change event. ''' evtname = 'TrackName' sec_sort_order = 0 def __init__(self, tick, trackName, insertion_order=0): # GenericEvent.__init__(self, tick) self.trackName = trackName.encode("ISO-8859-1") super(TrackName, self).__init__(tick, insertion_order) def __eq__(self, other): return (self.evtname == other.evtname and self.tick == other.tick and self.trackName == other.trackName) __hash__ = GenericEvent.__hash__ def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('B', 0xFF) midibytes += struct.pack('B', 0X03) dataLength = len(self.trackName) dataLengthVar = writeVarLength(dataLength) for i in dataLengthVar: midibytes += struct.pack("B", i) midibytes += self.trackName return midibytes class TimeSignature(GenericEvent): ''' A class that encapsulates a time signature. ''' evtname = 'TimeSignature' sec_sort_order = 0 def __init__(self, tick, numerator, denominator, clocks_per_tick, notes_per_quarter, insertion_order=0): self.numerator = numerator self.denominator = denominator self.clocks_per_tick = clocks_per_tick self.notes_per_quarter = notes_per_quarter super(TimeSignature, self).__init__(tick, insertion_order) def serialize(self, previous_event_tick): """Return a bytestring representation of the event, in the format required for writing into a standard midi file. """ midibytes = b"" code = 0xFF subcode = 0x58 varTime = writeVarLength(self.tick - previous_event_tick) for timeByte in varTime: midibytes += struct.pack('>B', timeByte) midibytes += struct.pack('>B', code) midibytes += struct.pack('>B', subcode) midibytes += struct.pack('>B', 0x04) midibytes += struct.pack('>B', self.numerator) midibytes += struct.pack('>B', self.denominator) midibytes += struct.pack('>B', self.clocks_per_tick) # 32nd notes per quarter note midibytes += struct.pack('>B', self.notes_per_quarter) return midibytes class MIDITrack(object): ''' A class that encapsulates a MIDI track ''' def __init__(self, removeDuplicates, deinterleave): '''Initialize the MIDITrack object. ''' self.headerString = struct.pack('cccc', b'M', b'T', b'r', b'k') self.dataLength = 0 # Is calculated after the data is in place self.MIDIdata = b"" self.closed = False self.eventList = [] self.MIDIEventList = [] self.remdep = removeDuplicates self.deinterleave = deinterleave def addNoteByNumber(self, channel, pitch, tick, duration, volume, annotation=None, insertion_order=0): ''' Add a note by chromatic MIDI number ''' self.eventList.append(NoteOn(channel, pitch, tick, duration, volume, annotation=annotation, insertion_order=insertion_order)) # This event is not in chronological order. But before writing all the # events to the file, I sort self.eventlist on (tick, sec_sort_order, insertion_order) # which puts the events in chronological order. self.eventList.append(NoteOff(channel, pitch, tick + duration, volume, annotation=annotation, insertion_order=insertion_order)) def addControllerEvent(self, channel, tick, controller_number, parameter, insertion_order=0): ''' Add a controller event. ''' self.eventList.append(ControllerEvent(channel, tick, controller_number, parameter, insertion_order=insertion_order)) def addPitchWheelEvent(self, channel, tick, pitch_wheel_value, insertion_order=0): ''' Add a pitch wheel event. ''' self.eventList.append(PitchWheelEvent(channel, tick, pitch_wheel_value, insertion_order=insertion_order)) def addTempo(self, tick, tempo, insertion_order=0): ''' Add a tempo change (or set) event. ''' self.eventList.append(Tempo(tick, tempo, insertion_order=insertion_order)) def addSysEx(self, tick, manID, payload, insertion_order=0): ''' Add a SysEx event. ''' self.eventList.append(SysExEvent(tick, manID, payload, insertion_order=insertion_order)) def addUniversalSysEx(self, tick, code, subcode, payload, sysExChannel=0x7F, realTime=False, insertion_order=0): ''' Add a Universal SysEx event. ''' self.eventList.append(UniversalSysExEvent(tick, realTime, sysExChannel, code, subcode, payload, insertion_order=insertion_order)) def addProgramChange(self, channel, tick, program, insertion_order=0): ''' Add a program change event. ''' self.eventList.append(ProgramChange(channel, tick, program, insertion_order=insertion_order)) def addChannelPressure(self, channel, tick, pressure_value, insertion_order=0): ''' Add a channel pressure event. ''' self.eventList.append(ChannelPressureEvent(channel, tick, pressure_value, insertion_order=insertion_order)) def addTrackName(self, tick, trackName, insertion_order=0): ''' Add a track name event. ''' self.eventList.append(TrackName(tick, trackName, insertion_order=insertion_order)) def addTimeSignature(self, tick, numerator, denominator, clocks_per_tick, notes_per_quarter, insertion_order=0): ''' Add a time signature. ''' self.eventList.append(TimeSignature(tick, numerator, denominator, clocks_per_tick, notes_per_quarter, insertion_order=insertion_order)) def addCopyright(self, tick, notice, insertion_order=0): ''' Add a copyright notice ''' self.eventList.append(Copyright(tick, notice, insertion_order=insertion_order)) def addKeySignature(self, tick, accidentals, accidental_type, mode, insertion_order=0): ''' Add a copyright notice ''' self.eventList.append(KeySignature(tick, accidentals, accidental_type, mode, insertion_order=insertion_order)) def addText(self, tick, text, insertion_order=0): ''' Add a text event ''' self.eventList.append(Text(tick, text, insertion_order=insertion_order)) def changeNoteTuning(self, tunings, sysExChannel=0x7F, realTime=True, tuningProgam=0, insertion_order=0): ''' Change the tuning of MIDI notes ''' payload = struct.pack('>B', tuningProgam) payload = payload + struct.pack('>B', len(tunings)) for (noteNumber, frequency) in tunings: payload = payload + struct.pack('>B', noteNumber) MIDIFreqency = frequencyTransform(frequency) for byte in MIDIFreqency: payload = payload + struct.pack('>B', byte) self.eventList.append(UniversalSysExEvent(0, realTime, sysExChannel, 8, 2, payload, insertion_order=insertion_order)) def processEventList(self): ''' Process the event list, creating a MIDIEventList, which is then sorted to be in chronological order by start tick. ''' self.MIDIEventList = [evt for evt in self.eventList] # Assumptions in the code expect the list to be time-sorted. self.MIDIEventList.sort(key=sort_events) if self.deinterleave: self.deInterleaveNotes() def removeDuplicates(self): ''' Remove duplicates from the eventList. This function will remove duplicates from the eventList. This is necessary because we the MIDI event stream can become confused otherwise. ''' # For this algorithm to work, the events in the eventList must be # hashable (that is, they must have a __hash__() and __eq__() function # defined). s = set(self.eventList) self.eventList = list(s) self.eventList.sort(key=sort_events) def closeTrack(self): ''' Called to close a track before writing This function should be called to "close a track," that is to prepare the actual data stream for writing. Duplicate events are removed from the eventList, and the MIDIEventList is created. Called by the parent MIDIFile object. ''' if self.closed: return self.closed = True if self.remdep: self.removeDuplicates() self.processEventList() def writeMIDIStream(self): ''' Write the meta data and note data to the packed MIDI stream. ''' # Process the events in the eventList self.writeEventsToStream() # Write MIDI close event. self.MIDIdata += struct.pack('BBBB', 0x00, 0xFF, 0x2F, 0x00) # Calculate the entire length of the data and write to the header self.dataLength = struct.pack('>L', len(self.MIDIdata)) def writeEventsToStream(self): ''' Write the events in MIDIEvents to the MIDI stream. MIDIEventList is presumed to be already sorted in chronological order. ''' previous_event_tick = 0 for event in self.MIDIEventList: self.MIDIdata += event.serialize(previous_event_tick) # previous_event_tick = event.tick # I do not like that adjustTimeAndOrigin() changes GenericEvent.tick # from absolute to relative. I intend to change that, and just # calculate the relative tick here, without changing GenericEvent.tick def deInterleaveNotes(self): ''' Correct Interleaved notes. Because we are writing multiple notes in no particular order, we can have notes which are interleaved with respect to their start and stop times. This method will correct that. It expects that the MIDIEventList has been time-ordered. ''' tempEventList = [] stack = {} for event in self.MIDIEventList: if event.evtname in ['NoteOn', 'NoteOff']: # !!! Pitch 101 channel 5 produces the same key as pitch 10 channel 15. # !!! This is not the only pair of pitch,channel tuples which # !!! collide to the same key, just one example. Should fix by # !!! putting a separator char between pitch and channel. noteeventkey = str(event.pitch) + str(event.channel) if event.evtname == 'NoteOn': if noteeventkey in stack: stack[noteeventkey].append(event.tick) else: stack[noteeventkey] = [event.tick] tempEventList.append(event) elif event.evtname == 'NoteOff': if len(stack[noteeventkey]) > 1: event.tick = stack[noteeventkey].pop() tempEventList.append(event) else: stack[noteeventkey].pop() tempEventList.append(event) else: tempEventList.append(event) self.MIDIEventList = tempEventList # Note NoteOff events have a lower secondary sort key than NoteOn # events, so this sort will make concomitant NoteOff events # processed first. self.MIDIEventList.sort(key=sort_events) def adjustTimeAndOrigin(self, origin, adjust): ''' Adjust Times to be relative, and zero-origined. If adjust is True, the track will be shifted. Regardelss times are converted to relative values here. ''' if len(self.MIDIEventList) == 0: return tempEventList = [] internal_origin = origin if adjust else 0 runningTick = 0 for event in self.MIDIEventList: adjustedTick = event.tick - internal_origin event.tick = adjustedTick - runningTick runningTick = adjustedTick tempEventList.append(event) self.MIDIEventList = tempEventList def writeTrack(self, fileHandle): ''' Write track to disk. ''' fileHandle.write(self.headerString) fileHandle.write(self.dataLength) fileHandle.write(self.MIDIdata) class MIDIHeader(object): ''' Class to encapsulate the MIDI header structure. This class encapsulates a MIDI header structure. It isn't used for much, but it will create the appropriately packed identifier string that all MIDI files should contain. It is used by the MIDIFile class to create a complete and well formed MIDI pattern. ''' def __init__(self, numTracks, file_format, ticks_per_quarternote): ''' Initialize the data structures :param numTracks: The number of tracks the file contains. Integer, one or greater :param file_format: The format of the multi-track file. This should either be ``1`` (the default, and the most widely supported format) or ``2``. :param ticks_per_quarternote: The number of ticks per quarter note is what the Standard MIDI File Format Specification calls "division". Ticks are the integer unit of time in the SMF, and in every MIDI sequencer I am aware of. Common values are 120, 240, 384, 480, 960. Note that all these numbers are evenly divisible by 2,3,4,6,8,12,16, and 24, except 120 does not have 16 as a divisor. ''' self.headerString = struct.pack('cccc', b'M', b'T', b'h', b'd') self.headerSize = struct.pack('>L', 6) # Format 1 = multi-track file self.formatnum = struct.pack('>H', file_format) self.numeric_format = file_format self.numTracks = struct.pack('>H', numTracks) self.ticks_per_quarternote = struct.pack('>H', ticks_per_quarternote) def writeFile(self, fileHandle): fileHandle.write(self.headerString) fileHandle.write(self.headerSize) fileHandle.write(self.formatnum) fileHandle.write(self.numTracks) fileHandle.write(self.ticks_per_quarternote) class MIDIFile(object): ''' A class that encapsulates a full, well-formed MIDI file object. This is a container object that contains a header (:class:`MIDIHeader`), one or more tracks (class:`MIDITrack`), and the data associated with a proper and well-formed MIDI file. ''' def __init__(self, numTracks=1, removeDuplicates=True, deinterleave=True, adjust_origin=False, file_format=1, ticks_per_quarternote=TICKSPERQUARTERNOTE, eventtime_is_ticks=False): '''Initialize the MIDIFile class :param numTracks: The number of tracks the file contains. Integer, one or greater :param removeDuplicates: If set to ``True`` remove duplicate events before writing to disk :param deinterleave: If set to ``True`` deinterleave the notes in the stream :param adjust_origin: If set to ``True`` shift all the events in the tracks so that the first event takes place at time t=0. Default is ``False`` :param file_format: The format of the multi-track file. This should either be ``1`` (the default, and the most widely supported format) or ``2``. :param ticks_per_quarternote: The number of ticks per quarter note is what the Standard MIDI File Format Specification calls "division". Ticks are the integer unit of time in the SMF, and in most if not all MIDI sequencers. Common values are 120, 240, 384, 480, 960. Note that all these numbers are evenly divisible by 2,3,4,6,8,12,16, and 24, except 120 does not have 16 as a divisor. :param eventtime_is_ticks: If set True means event time and duration argument values are integer ticks instead of fractional quarter notes. Note that the default for ``adjust_origin`` will change in a future release, so one should probably explicitly set it. In a format 1 file, it would be a rare cirumstance where adjusting the origin of each track to the track's first note makes any sense. Example: .. code:: # Create a two-track MIDIFile from midiutil.MidiFile import MIDIFile midi_file = MIDIFile(1, adjust_origin=False) A Note on File Formats ---------------------- In previous versions of this code the file written was format 2 (which can be thought of as a collection of independent tracks) but was identified as format 1. In this version one can specify either format 1 or 2. In format 1 files there is a separate tempo track which contains tempo and time signature data, but contains no note data. If one creates a single track format 1 file the actual file has two tracks -- one for tempo data and one for note data. In the track indexing the tempo track can be ignored. In other words track 0 is the note track (the second track in the file). However, tempo and time signature data will be written to the first, tempo track. This is done to try and preserve as much interoperability with previous versions as possible. In a format 2 file all tracks are indexed and the track parameter is interpreted literally. ''' self.tracks = list() if file_format == 1: self.numTracks = numTracks + 1 # self.tracks[0] is the baked-in tempo track else: self.numTracks = numTracks self.header = MIDIHeader(self.numTracks, file_format, ticks_per_quarternote) self.adjust_origin = adjust_origin self.closed = False self.ticks_per_quarternote = ticks_per_quarternote self.eventtime_is_ticks = eventtime_is_ticks if self.eventtime_is_ticks: self.time_to_ticks = lambda x: x else: self.time_to_ticks = self.quarter_to_tick for i in range(0, self.numTracks): self.tracks.append(MIDITrack(removeDuplicates, deinterleave)) # to keep track of the order of insertion for new sorting self.event_counter = 0 # Public Functions. These (for the most part) wrap the MIDITrack functions, # where most Processing takes place. def quarter_to_tick(self, quarternote_time): return int(quarternote_time * self.ticks_per_quarternote) def tick_to_quarter(self, ticknum): return float(ticknum) / self.ticks_per_quarternote def addNote(self, track, channel, pitch, time, duration, volume, annotation=None): """ Add notes to the MIDIFile object :param track: The track to which the note is added. :param channel: the MIDI channel to assign to the note. [Integer, 0-15] :param pitch: the MIDI pitch number [Integer, 0-127]. :param time: the time at which the note sounds. The value can be either quarter notes [Float], or ticks [Integer]. Ticks may be specified by passing eventtime_is_ticks=True to the MIDIFile constructor. The default is quarter notes. :param duration: the duration of the note. Like the time argument, the value can be either quarter notes [Float], or ticks [Integer]. :param volume: the volume (velocity) of the note. [Integer, 0-127]. :param annotation: Arbitrary data to attach to the note. The ``annotation`` parameter attaches arbitrary data to the note. This is not used in the code, but can be useful anyway. As an example, I have created a project that uses MIDIFile to write `csound `_ orchestra files directly from the class ``EventList``. """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addNoteByNumber(channel, pitch, self.time_to_ticks(time), self.time_to_ticks(duration), volume, annotation=annotation, insertion_order=self.event_counter) self.event_counter += 1 def addTrackName(self, track, time, trackName): """ Name a track. :param track: The track to which the name is assigned. :param time: The time (in beats) at which the track name event is placed. In general this should probably be time 0 (the beginning of the track). :param trackName: The name to assign to the track [String] """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addTrackName(self.time_to_ticks(time), trackName, insertion_order=self.event_counter) self.event_counter += 1 def addTimeSignature(self, track, time, numerator, denominator, clocks_per_tick, notes_per_quarter=8): ''' Add a time signature event. :param track: The track to which the signature is assigned. Note that in a format 1 file this parameter is ignored and the event is written to the tempo track :param time: The time (in beats) at which the event is placed. In general this should probably be time 0 (the beginning of the track). :param numerator: The numerator of the time signature. [Int] :param denominator: The denominator of the time signature, expressed as a power of two (see below). [Int] :param clocks_per_tick: The number of MIDI clock ticks per metronome click (see below). :param notes_per_quarter: The number of annotated 32nd notes in a MIDI quarter note. This is almost always 8 (the default), but some sequencers allow this value to be changed. Unless you know that your sequencing software supports it, this should be left at its default value. The data format for this event is a little obscure. The ``denominator`` should be specified as a power of 2, with a half note being one, a quarter note being two, and eight note being three, etc. Thus, for example, a 4/4 time signature would have a ``numerator`` of 4 and a ``denominator`` of 2. A 7/8 time signature would be a ``numerator`` of 7 and a ``denominator`` of 3. The ``clocks_per_tick`` argument specifies the number of clock ticks per metronome click. By definition there are 24 ticks in a quarter note, so a metronome click per quarter note would be 24. A click every third eighth note would be 3 * 12 = 36. The ``notes_per_quarter`` value is also a little confusing. It specifies the number of 32nd notes in a MIDI quarter note. Usually there are 8 32nd notes in a quarter note (8/32 = 1/4), so the default value is 8. However, one can change this value if needed. Setting it to 16, for example, would cause the music to play at double speed, as there would be 16/32 (or what could be considered *two* quarter notes for every one MIDI quarter note. Note that both the ``clocks_per_tick`` and the ``notes_per_quarter`` are specified in terms of quarter notes, even is the score is not a quarter-note based score (i.e., even if the denominator is not ``4``). So if you're working with a time signature of, say, 6/8, one still needs to specify the clocks per quarter note. ''' if self.header.numeric_format == 1: track = 0 self.tracks[track].addTimeSignature(self.time_to_ticks(time), numerator, denominator, clocks_per_tick, notes_per_quarter, insertion_order=self.event_counter) self.event_counter += 1 def addTempo(self, track, time, tempo): """ Add notes to the MIDIFile object :param track: The track to which the tempo event is added. Note that in a format 1 file this parameter is ignored and the tempo is written to the tempo track :param time: The time (in beats) at which tempo event is placed :param tempo: The tempo, in Beats per Minute. [Integer] """ if self.header.numeric_format == 1: track = 0 self.tracks[track].addTempo(self.time_to_ticks(time), tempo, insertion_order=self.event_counter) self.event_counter += 1 def addCopyright(self, track, time, notice): """ Add a copyright notice to the MIDIFile object :param track: The track to which the notice is added. :param time: The time (in beats) at which notice event is placed. In general this sould be time t=0 :param notice: The copyright notice [String] """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addCopyright(self.time_to_ticks(time), notice, insertion_order=self.event_counter) self.event_counter += 1 def addKeySignature(self, track, time, accidentals, accidental_type, mode, insertion_order=0): ''' Add a Key Signature to a track :param track: The track to which this should be added :param time: The time at which the signature should be placed :param accidentals: The number of accidentals in the key signature :param accidental_type: The type of accidental :param mode: The mode of the scale The easiest way to use this function is to make sure that the symbolic constants for accidental_type and mode are imported. By doing this: .. code:: from midiutil.MidiFile import * one gets the following constants defined: * ``SHARPS`` * ``FLATS`` * ``MAJOR`` * ``MINOR`` So, for example, if one wanted to create a key signature for a minor scale with three sharps: .. code:: MyMIDI.addKeySignature(0, 0, 3, SHARPS, MINOR) ''' if self.header.numeric_format == 1: track = 0 # User reported that this is needed. self.tracks[track].addKeySignature(self.time_to_ticks(time), accidentals, accidental_type, mode, insertion_order=self.event_counter) self.event_counter += 1 def addText(self, track, time, text): """ Add a text event :param track: The track to which the notice is added. :param time: The time (in beats) at which text event is placed. :param text: The text to adde [ASCII String] """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addText(self.time_to_ticks(time), text, insertion_order=self.event_counter) self.event_counter += 1 def addProgramChange(self, tracknum, channel, time, program): """ Add a MIDI program change event. :param tracknum: The zero-based track number to which program change event is added. :param channel: the MIDI channel to assign to the event. [Integer, 0-15] :param time: The time (in beats) at which the program change event is placed [Float]. :param program: the program number. [Integer, 0-127]. """ if self.header.numeric_format == 1: tracknum += 1 self.tracks[tracknum].addProgramChange(channel, self.time_to_ticks(time), program, insertion_order=self.event_counter) self.event_counter += 1 def addChannelPressure(self, tracknum, channel, time, pressure_value): """ Add a Channel Pressure event. :param tracknum: The zero-based track number to which channel pressure event is added. :param channel: the MIDI channel to assign to the event. [Integer, 0-15] :param time: The time (in beats) at which the channel pressure event is placed [Float]. :param pressure_value: the pressure value. [Integer, 0-127]. """ if self.header.numeric_format == 1: tracknum += 1 track = self.tracks[tracknum] track.addChannelPressure(channel, self.time_to_ticks(time), pressure_value, insertion_order=self.event_counter) self.event_counter += 1 def addControllerEvent(self, track, channel, time, controller_number, parameter): """ Add a channel control event :param track: The track to which the event is added. :param channel: the MIDI channel to assign to the event. [Integer, 0-15] :param time: The time (in beats) at which the event is placed [Float]. :param controller_number: The controller ID of the event. :param parameter: The event's parameter, the meaning of which varies by event type. """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addControllerEvent(channel, self.time_to_ticks(time), controller_number, parameter, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 def addPitchWheelEvent(self, track, channel, time, pitchWheelValue): """ Add a channel pitch wheel event :param track: The track to which the event is added. :param channel: the MIDI channel to assign to the event. [Integer, 0-15] :param time: The time (in beats) at which the event is placed [Float]. :param pitchWheelValue: 0 for no pitch change. [Integer, -8192-8192] """ if self.header.numeric_format == 1: track += 1 self.tracks[track].addPitchWheelEvent(channel, self.time_to_ticks(time), pitchWheelValue, insertion_order=self.event_counter) self.event_counter += 1 def makeRPNCall(self, track, channel, time, controller_msb, controller_lsb, data_msb, data_lsb, time_order=False): ''' Perform a Registered Parameter Number Call :param track: The track to which this applies :param channel: The channel to which this applies :param time: The time of the event :param controller_msb: The Most significant byte of the controller. In common usage this will usually be 0 :param controller_lsb: The Least significant Byte for the controller message. For example, for a fine-tuning change this would be 01. :param data_msb: The Most Significant Byte of the controller's parameter. :param data_lsb: The Least Significant Byte of the controller's parameter. If not needed this should be set to ``None`` :param time_order: Order the control events in time (see below) As an example, if one were to change a channel's tuning program:: makeRPNCall(track, channel, time, 0, 3, 0, program) (Note, however, that there is a convenience function, ``changeTuningProgram``, that does this for you.) Registered/Non-Registered Parameter Number (RPN / NRPN) ------------------------------------------------------- Controller number 6 (Data Entry), in conjunction with Controller numbers 96 (Data Increment), 97 (Data Decrement), 98 (Registered Parameter Number LSB), 99 (Registered Parameter Number MSB), 100 (Non-Registered Parameter Number LSB), and 101 (Non-Registered Parameter Number MSB), extend the number of controllers available via MIDI. Parameter data is transferred by first selecting the parameter number to be edited using controllers 98 and 99 or 100 and 101, and then adjusting the data value for that parameter using controller number 6, 96, or 97. RPN and NRPN are typically used to send parameter data to a synthesizer in order to edit sound patches or other data. Registered parameters are those which have been assigned some particular function by the MIDI Manufacturers Association (MMA) and the Japan MIDI Standards Committee (JMSC). For example, there are Registered Parameter numbers assigned to control pitch bend sensitivity and master tuning for a synthesizer. Non-Registered parameters have not been assigned specific functions, and may be used for different functions by different manufacturers. The ``time_order`` parameter is something of a work-around for sequencers that do not preserve the order of events from the MIDI files they import. Within this code care is taken to preserve the order of events as specified, but some sequencers seem to transmit events occurring at the same time in an arbitrary order. By setting this parameter to ``True`` something of a work-around is performed: each successive event (of which there are three or four for this event type) is placed in the time stream a small delta from the preceding one. Thus, for example, the controllers are set before the data bytes in this call. ''' tick = self.time_to_ticks(time) if self.header.numeric_format == 1: track += 1 track = self.tracks[track] tick_incr = 1 if time_order else 0 track.addControllerEvent(channel, tick, 101, # parameter number MSB controller_msb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr track.addControllerEvent(channel, tick, 100, controller_lsb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr track.addControllerEvent(channel, tick, 6, data_msb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr if data_lsb is not None: track.addControllerEvent(channel, tick, 38, data_lsb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 def makeNRPNCall(self, track, channel, time, controller_msb, controller_lsb, data_msb, data_lsb, time_order=False): ''' Perform a Non-Registered Parameter Number Call :param track: The track to which this applies :param channel: The channel to which this applies :param time: The time of the event :param controller_msb: The Most significant byte of thecontroller. In common usage this will usually be 0 :param controller_lsb: The least significant byte for the controller message. For example, for a fine-tunning change this would be 01. :param data_msb: The most significant byte of the controller's parameter. :param data_lsb: The least significant byte of the controller's parameter. If none is needed this should be set to ``None`` :param time_order: Order the control events in time (see below) The ``time_order`` parameter is something of a work-around for sequencers that do not preserve the order of events from the MIDI files they import. Within this code care is taken to preserve the order of events as specified, but some sequencers seem to transmit events occurring at the same time in an arbitrary order. By setting this parameter to ``True`` something of a work-around is performed: each successive event (of which there are three or four for this event type) is placed in the time stream a small delta from the preceding one. Thus, for example, the controllers are set before the data bytes in this call. ''' tick = self.time_to_ticks(time) if self.header.numeric_format == 1: track += 1 track = self.tracks[track] tick_incr = 1 if time_order else 0 track.addControllerEvent(channel, tick, 99, controller_msb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr track.addControllerEvent(channel, tick, 98, controller_lsb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr track.addControllerEvent(channel, tick, 6, data_msb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 tick += tick_incr if data_lsb is not None: track.addControllerEvent(channel, tick, 38, data_lsb, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 def changeTuningBank(self, track, channel, time, bank, time_order=False): ''' Change the tuning bank for a selected track :param track: The track to which the data should be written :param channel: The channel for the event :param time: The time of the event :param bank: The tuning bank (0-127) :param time_order: Preserve the ordering of the component events by ordering in time. See ``makeRPNCall()`` for a discussion of when this may be necessary Note that this is a convenience function, as the same functionality is available from directly sequencing controller events. The specified tuning should already have been written to the stream with ``changeNoteTuning``. ''' self.makeRPNCall(track, channel, time, 0, 4, 0, bank, time_order=time_order) def changeTuningProgram(self, track, channel, time, program, time_order=False): ''' Change the tuning program for a selected track :param track: The track to which the data should be written :param channel: The channel for the event :param time: The time of the event :param program: The tuning program number (0-127) :param time_order: Preserve the ordering of the component events by ordering in time. See ``makeRPNCall()`` for a discussion of when this may be necessary Note that this is a convenience function, as the same functionality is available from directly sequencing controller events. The specified tuning should already have been written to the stream with ``changeNoteTuning``. ''' self.makeRPNCall(track, channel, time, 0, 3, 0, program, time_order=time_order) def changeNoteTuning(self, track, tunings, sysExChannel=0x7F, realTime=True, tuningProgam=0): """ Add a real-time MIDI tuning standard update to a track. :param track: The track to which the tuning is applied. :param tunings: A list to tuples representing the tuning. See below for an explanation. :param sysExChannel: The SysEx channel of the event. This is mapped to "manufacturer ID" in the event which is written. Unless there is a specific reason for changing it, it should be left at its default value. :param realTime: Speicifes if the Universal SysEx event should be flagged as real-time or non-real-time. As with the ``sysExChannel`` argument, this should in general be left at it's default value. :param tuningProgram: The tuning program number. This function specifically implements the "real time single note tuning change" (although the name is misleading, as multiple notes can be included in each event). It should be noted that not all hardware or software implements the MIDI tuning standard, and that which does often does not implement it in its entirety. The ``tunings`` argument is a list of tuples, in (*note number*, *frequency*) format. As an example, if one wanted to change the frequency on MIDI note 69 to 500 (it is normally 440 Hz), one could do it thus: .. code:: python from midiutil.MidiFile import MIDIFile MyMIDI = MIDIFile(1) tuning = [(69, 500)] MyMIDI.changeNoteTuning(0, tuning, tuningProgam=0) """ if self.header.numeric_format == 1: track += 1 self.tracks[track].changeNoteTuning(tunings, sysExChannel, realTime, tuningProgam, insertion_order=self.event_counter) self.event_counter += 1 def addSysEx(self, track, time, manID, payload): ''' Add a System Exclusive event. :param track: The track to which the event should be written :param time: The time of the event. :param manID: The manufacturer ID for the event :param payload: The payload for the event. This should be a binary-packed value, and will vary for each type and function. **Note**: This is a low-level MIDI function, so care must be used in constructing the payload. It is recommended that higher-level helper functions be written to wrap this function and construct the payload if a developer finds him or herself using the function heavily. ''' tick = self.time_to_ticks(time) if self.header.numeric_format == 1: track += 1 self.tracks[track].addSysEx(tick, manID, payload, insertion_order=self.event_counter) self.event_counter += 1 def addUniversalSysEx(self, track, time, code, subcode, payload, sysExChannel=0x7F, realTime=False): ''' Add a Univeral System Exclusive event. :param track: The track to which the event should be written :param time: The time of the event, in beats. :param code: The event code. [Integer] :param subcode: The event sub-code [Integer] :param payload: The payload for the event. This should be a binary-packed value, and will vary for each type and function. :param sysExChannel: The SysEx channel. :param realTime: Sets the real-time flag. Defaults to non-real-time. :param manID: The manufacturer ID for the event **Note**: This is a low-level MIDI function, so care must be used in constructing the payload. It is recommended that higher-level helper functions be written to wrap this function and construct the payload if a developer finds him or herself using the function heavily. As an example of such a helper function, see the ``changeNoteTuning()`` function, which uses the event to create a real-time note tuning update. ''' tick = self.time_to_ticks(time) if self.header.numeric_format == 1: track += 1 self.tracks[track].addUniversalSysEx(tick, code, subcode, payload, sysExChannel, realTime, insertion_order=self.event_counter) # noqa: E128 self.event_counter += 1 def writeFile(self, fileHandle): ''' Write the MIDI File. :param fileHandle: A file handle that has been opened for binary writing. ''' self.header.writeFile(fileHandle) # Close the tracks and have them create the MIDI event data structures. self.close() # Write the MIDI Events to file. for i in range(0, self.numTracks): self.tracks[i].writeTrack(fileHandle) def shiftTracks(self, offset=0): """Shift tracks to be zero-origined, or origined at offset. Note that the shifting of the time in the tracks uses the MIDIEventList -- in other words it is assumed to be called in the stage where the MIDIEventList has been created. This function, however, it meant to operate on the eventList itself. """ origin = 100000000 # A little silly, but we'll assume big enough tick_offset = self.time_to_ticks(offset) for track in self.tracks: if len(track.eventList) > 0: for event in track.eventList: if event.tick < origin: origin = event.tick for track in self.tracks: tempEventList = [] # runningTick = 0 for event in track.eventList: adjustedTick = event.tick - origin # event.time = adjustedTime - runningTick + tick_offset event.tick = adjustedTick + tick_offset # runningTick = adjustedTick tempEventList.append(event) track.eventList = tempEventList # End Public Functions ######################## def close(self): ''' Close the MIDIFile for further writing. To close the File for events, we must close the tracks, adjust the time to be zero-origined, and have the tracks write to their MIDI Stream data structure. ''' if self.closed: return for i in range(0, self.numTracks): self.tracks[i].closeTrack() # We want things like program changes to come before notes when # they are at the same time, so we sort the MIDI events by both # their start time and a secondary ordinality defined for each kind # of event. self.tracks[i].MIDIEventList.sort(key=sort_events) origin = self.findOrigin() for i in range(0, self.numTracks): self.tracks[i].adjustTimeAndOrigin(origin, self.adjust_origin) self.tracks[i].writeMIDIStream() self.closed = True def findOrigin(self): ''' Find the earliest time in the file's tracks.append. ''' origin = 100000000 # A little silly, but we'll assume big enough # Note: This code assumes that the MIDIEventList has been sorted, so this # should be insured before it is called. It is probably a poor design to do # this. # TODO: -- Consider making this less efficient but more robust by not # assuming the list to be sorted. for track in self.tracks: if len(track.MIDIEventList) > 0: if track.MIDIEventList[0].tick < origin: origin = track.MIDIEventList[0].tick return origin def writeVarLength(i): ''' Accept an integer, and serialize it as a MIDI file variable length quantity Some numbers in MTrk chunks are represented in a form called a variable- length quantity. These numbers are represented in a sequence of bytes, each byte holding seven bits of the number, and ordered most significant bits first. All bytes in the sequence except the last have bit 7 set, and the last byte has bit 7 clear. This form allows smaller numbers to be stored in fewer bytes. For example, if the number is between 0 and 127, it is thus represented exactly as one byte. A number between 128 and 16383 uses two bytes, and so on. Examples: Number VLQ 128 81 00 8192 C0 00 16383 FF 7F 16384 81 80 00 ''' if i == 0: return [0] vlbytes = [] hibit = 0x00 # low-order byte has high bit cleared. while i > 0: vlbytes.append(((i & 0x7f) | hibit) & 0xff) i >>= 7 hibit = 0x80 vlbytes.reverse() # put most-significant byte first, least significant last return vlbytes # readVarLength is taken from the MidiFile class. def readVarLength(offset, buffer): ''' A function to read a MIDI variable length variable. It returns a tuple of the value read and the number of bytes processed. The input is an offset into the buffer, and the buffer itself. ''' toffset = offset output = 0 bytesRead = 0 while True: output = output << 7 byte = struct.unpack_from('>B', buffer, toffset)[0] toffset = toffset + 1 bytesRead = bytesRead + 1 output = output + (byte & 127) if (byte & 128) == 0: break return (output, bytesRead) def frequencyTransform(freq): ''' Returns a three-byte transform of a frequency. ''' resolution = 16384 freq = float(freq) dollars = 69 + 12 * math.log(freq / (float(440)), 2) firstByte = int(dollars) lowerFreq = 440 * pow(2.0, ((float(firstByte) - 69.0) / 12.0)) centDif = 1200 * math.log((freq / lowerFreq), 2) if freq != lowerFreq else 0 cents = round(centDif / 100 * resolution) # round? secondByte = min([int(cents) >> 7, 0x7F]) thirdByte = cents - (secondByte << 7) thirdByte = min([thirdByte, 0x7f]) if thirdByte == 0x7f and secondByte == 0x7F and firstByte == 0x7F: thirdByte = 0x7e thirdByte = int(thirdByte) return [firstByte, secondByte, thirdByte] def returnFrequency(freqBytes): ''' The reverse of frequencyTransform. Given a byte stream, return a frequency. ''' resolution = 16384.0 baseFrequency = 440 * pow(2.0, (float(freqBytes[0] - 69.0) / 12.0)) frac = (float((int(freqBytes[1]) << 7) + int(freqBytes[2])) * 100.0) / resolution frequency = baseFrequency * pow(2.0, frac / 1200.0) return frequency def sort_events(event): ''' .. py:function:: sort_events(event) The key function used to sort events (both MIDI and Generic) :param event: An object of type :class:`MIDIEvent` or (a derrivative) :class:`GenericEvent` This function should be provided as the ``key`` for both ``list.sort()`` and ``sorted()``. By using it sorting will be as follows: * Events are ordered in time. An event that takes place earlier will appear earlier * If two events happen at the same time, the secondary sort key is ``sec_sort_order``. Thus a class of events can be processed earlier than another. One place this is used in the code is to make sure that note off events are processed before note on events. * If event time and event ordinality are the same, they are sorted in the order in which they were originally added to the list. Thus, for example, if one is making an RPN call one can specify the controller change events in the proper order and be sure that they will end up in the file that way. ''' return (event.tick, event.sec_sort_order, event.insertion_order)