#!/usr/bin/env python
# Read MIDI file track and synthesize with PySynth A
# Usage:
# python readmidi.py file.mid [tracknum] [file.wav] [--syn_b/--syn_c/--syn_d/--syn_e/--syn_p/--syn_s/--syn_samp]
# Based on code from https://github.com/osakared/midifile.py
# which appears to be based on
# https://github.com/gasman/jasmid/blob/master/midifile.js
# Original license:
"""
Copyright (c) 2014, Thomas J. Webb
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
import struct
[docs]class Note(object):
"Represents a single MIDI note"
note_names = ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"]
def __init__(self, channel, pitch, velocity, start, duration=0):
self.channel = channel
self.pitch = pitch
self.velocity = velocity
self.start = start
self.duration = duration
def __str__(self):
s = Note.note_names[(self.pitch - 9) % 12]
s += str(self.pitch // 12 - 1)
s += " " + str(self.velocity)
s += " " + str(self.start) + " " + str(self.start + self.duration) + " "
return s
[docs] def get_end(self):
return self.start + self.duration
[docs]class MidiFile(object):
"Represents the notes in a MIDI file"
[docs] def read_byte(self, file):
return struct.unpack("B", file.read(1))[0]
[docs] def read_variable_length(self, file, counter):
counter -= 1
num = self.read_byte(file)
if num & 0x80:
num = num & 0x7F
while True:
counter -= 1
c = self.read_byte(file)
num = (num << 7) + (c & 0x7F)
if not (c & 0x80):
break
return (num, counter)
def __init__(self, file_name):
self.tempo = 120
try:
file = open(file_name, "rb")
if file.read(4) != b"MThd":
raise Exception("Not a MIDI file")
self.file_name = file_name
size = struct.unpack(">i", file.read(4))[0]
if size != 6:
raise Exception("Unusual MIDI file with non-6 sized header")
self.format = struct.unpack(">h", file.read(2))[0]
self.track_count = struct.unpack(">h", file.read(2))[0]
self.time_division = struct.unpack(">h", file.read(2))[0]
# Now to fill out the arrays with the notes
self.tracks = []
for i in range(0, self.track_count):
self.tracks.append([])
for nn, track in enumerate(self.tracks):
abs_time = 0.0
if file.read(4) != b"MTrk":
raise Exception("Not a valid track")
size = struct.unpack(">i", file.read(4))[0]
# To keep track of running status
last_flag = None
while size > 0:
delta, size = self.read_variable_length(file, size)
delta /= float(self.time_division)
abs_time += delta
size -= 1
flag = self.read_byte(file)
# Sysex messages
if flag == 0xF0 or flag == 0xF7:
# print "Sysex"
while True:
size -= 1
if self.read_byte(file) == 0xF7:
break
# Meta messages
elif flag == 0xFF:
size -= 1
type = self.read_byte(file)
if type == 0x2F: # end of track event
self.read_byte(file)
size -= 1
break
print("Meta: " + str(type))
length, size = self.read_variable_length(file, size)
message = file.read(length)
# if type not in [0x0, 0x7, 0x20, 0x2F, 0x51, 0x54, 0x58, 0x59, 0x7F]:
print(length, message)
if type == 0x51: # qpm/bpm
# http://www.recordingblogs.com/sa/Wiki?topic=MIDI+Set+Tempo+meta+message
self.tempo = 6e7 / struct.unpack(">i", b"\x00" + message)[0]
print("tempo =", self.tempo, "bpm")
# MIDI messages
else:
if flag & 0x80:
type_and_channel = flag
size -= 1
param1 = self.read_byte(file)
last_flag = flag
else:
type_and_channel = last_flag
param1 = flag
type = (type_and_channel & 0xF0) >> 4
channel = type_and_channel & 0xF
if type == 0xC: # detect MIDI program change
print("program change, channel", channel, "=", param1)
continue
size -= 1
param2 = self.read_byte(file)
# detect MIDI ons and MIDI offs
if type == 0x9:
track.append(Note(channel, param1, param2, abs_time))
elif type == 0x8:
for note in reversed(track):
if note.channel == channel and note.pitch == param1:
note.duration = abs_time - note.start
break
except Exception as e:
print("Cannot parse MIDI file: " + str(e))
finally:
file.close()
def __str__(self):
s = ""
for i, track in enumerate(self.tracks):
s += "Track " + str(i + 1) + "\n"
for note in track:
s += str(note) + "\n"
return s
[docs]def getdur(a, b):
"Calculate note length for PySynth"
return 4 / (b - a)
if __name__ == "__main__":
import sys
m = MidiFile(sys.argv[1])
if len(sys.argv) > 2:
tracknum = int(sys.argv[2])
else:
tracknum = 1
if len(sys.argv) > 3:
filename = sys.argv[3]
else:
filename = "midi.wav"
print()
print("Track first notes")
for t, n in enumerate(m.tracks):
if len(n) > 0:
print(t, n[0], len(n))
song = []
notes = {}
def getnote(q):
for x in q.keys():
if q[x] >= 0:
return x
return None
def gettotal():
t = 0
for x, y in song:
t += 4 / y
return t
for n in m.tracks[tracknum]:
print(n)
nn = str(n).split()
start, stop = float(nn[2]), float(nn[3])
if start != stop: # note ends because of NOTE OFF event
if start - gettotal() > 0:
song.append(("r", getdur(gettotal(), start)))
print("r1")
song.append((nn[0].lower(), getdur(start, stop)))
elif (
float(nn[1]) == 0 and notes.get(nn[0].lower(), -1) >= 0
): # note ends because of NOTE ON with velocity = 0
if notes[nn[0].lower()] - gettotal() > 0:
song.append(("r", getdur(gettotal(), notes[nn[0].lower()])))
print("r2")
song.append((nn[0].lower(), getdur(notes[nn[0].lower()], start)))
notes[nn[0].lower()] = -1
elif (
float(nn[1]) > 0 and notes.get(nn[0].lower(), -1) == -1
): # note ends because of new note
old = getnote(notes)
if old != None:
if notes[old] != start:
song.append((old, getdur(notes[old], start)))
notes[old] = -1
elif start - gettotal() > 0:
song.append(("r", getdur(gettotal(), start)))
print("r3")
notes[nn[0].lower()] = start
print()
print("Song")
print(song)
if "--syn_b" in sys.argv:
import pysynth_b as pysynth
elif "--syn_s" in sys.argv:
import pysynth_s as pysynth
elif "--syn_e" in sys.argv:
import pysynth_e as pysynth
elif "--syn_c" in sys.argv:
import pysynth_c as pysynth
elif "--syn_d" in sys.argv:
import pysynth_d as pysynth
elif "--syn_p" in sys.argv:
import pysynth_p as pysynth
elif "--syn_samp" in sys.argv:
import pysynth_samp as pysynth
else:
import pysynth
pysynth.make_wav(song, fn=filename, bpm=m.tempo)
