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# GNU Solfege - free ear training software
# Copyright (C) 2000, 2001, 2002, 2003, 2004, 2007, 2008 Tom Cato Amundsen
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
def mf_delta(i):
assert isinstance(i, int) and i >= 0
vect = []
v = []
not_first = 0
while 1:
bits = i & 0x7f
i = i >> 7
v.insert(0, bits+not_first*0x80)
not_first = 1
if i == 0: # hvis det ikke er flere bit'er igjen
break
vect = vect + v
return vect
def mf_int16(i):
assert isinstance(i, int) and 0 <= i < 2**16
return [i >> 8 & 0xff, i & 0xff]
def mf_int24(i):
assert isinstance(i, int) and 0 <= i < 2**24
return [i >> 16 & 0xff, i >> 8 & 0xff, i & 0xff]
def mf_int32(i):
assert isinstance(i, int) and 0 <= i < 2L**32
return [i >> 24 & 0xff, i >> 16 & 0xff, i >> 8 & 0xff, i & 0xff]
def write_int16(f, i):
assert isinstance(i, int) and 0 <= i < 2**16
f.write(chr(i >> 8 & 0xff))
f.write(chr(i & 0xff))
def write_int32(f, i):
assert isinstance(i, int) and 0 <= i < 2L**32
f.write(chr(i >> 24 & 0xff))
f.write(chr(i >> 16 & 0xff))
f.write(chr(i >> 8 & 0xff))
f.write(chr(i & 0xff))
MIDI_NOTE_OFF = 0x80
MIDI_NOTE_ON = 0x90
MIDI_PROGRAM_CHANGE = 0xc0
def mf_tempo(n):
"""
n -- number of quarter tones per minute.
"""
# now Code to set tempo
v = mf_delta(0) + [0xff, 0x51, 0x03] + mf_int24(int(500000*120/n))
return v
def mf_timesig(numerator, denuminator):
d = {0:1, 2:1, 4:2, 8:3, 16:4, 32:5, 64:6}[denuminator]
return mf_delta(0) + [0xff, 0x58, 0x04,
numerator, d, # 4/4 2=4-del 3=8-del 4=16-del
0x10, #0x18
0x08]
def mf_program_change(chan, prg):
assert 0 <= chan < 16
return mf_delta(0) + [chan+MIDI_PROGRAM_CHANGE, prg]
def mf_note_on(delta, chan, note, vel):
assert 0 <= chan < 16
return mf_delta(delta) + [chan+MIDI_NOTE_ON, note, vel]
def mf_note_off(delta, chan, note, vel):
assert 0 <= chan < 16
return mf_delta(delta) + [chan+MIDI_NOTE_OFF, note, vel]
def mf_end_of_track():
return [0x0, 0xff, 0x2f, 0x00]
def write_vect(f, v):
for c in v:
assert isinstance(c, int) and 0 <= c < 256
f.write(chr(c))
class MThd:
PPQN = 96
def __init__(self, f):
v = []
# MIDI file format:
# 0: the file contains one single track containing midi data on
# possibly all 16 midi channels
# 1: the file contains one or more simultaneous (ie, all start
# from an assumed time of 0) tracks, perhaps each on a single
# midi channel.
# 2: the file contains one or more sequentially independant
# single-track patterns.
# We will use format 1.
v = v + mf_int16(1)
# How many tracks are stored in the file.
v = v + mf_int16(1)
# Wow many Pulses (i.e. clocks) Per Quarter Note resolution
# the time-stamps are based upon.
v = v + mf_int16(MThd.PPQN)
f.write("MThd")
write_int32(f, len(v)) #chunk len
write_vect(f, v)
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