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Created Oct 5, 2009

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# smidi.py: A simple midi-file library
# make a single file version for midi-outfile only.
# Original code is from Max M's site here (GPL)
# http://www.mxm.dk/products/public/pythonmidi
# Modified by korakot,
# http://snippets.dzone.com/posts/show/572
"""
include source codes from
- constants.py
- DataTypeConverters.py
- RawOutstreamFile.py
- MidiOutStream.py
- MidiOutFile.py
"""
from struct import pack, unpack
from types import StringType
from cStringIO import StringIO
#=================== constants.py ===================================#
###################################################
## Definitions of the different midi events
###################################################
## Midi channel events (The most usual events)
## also called "Channel Voice Messages"
NOTE_OFF = 0x80
# 1000cccc 0nnnnnnn 0vvvvvvv (channel, note, velocity)
NOTE_ON = 0x90
# 1001cccc 0nnnnnnn 0vvvvvvv (channel, note, velocity)
AFTERTOUCH = 0xA0
# 1010cccc 0nnnnnnn 0vvvvvvv (channel, note, velocity)
CONTINUOUS_CONTROLLER = 0xB0 # see Channel Mode Messages!!!
# 1011cccc 0ccccccc 0vvvvvvv (channel, controller, value)
PATCH_CHANGE = 0xC0
# 1100cccc 0ppppppp (channel, program)
CHANNEL_PRESSURE = 0xD0
# 1101cccc 0ppppppp (channel, pressure)
PITCH_BEND = 0xE0
# 1110cccc 0vvvvvvv 0wwwwwww (channel, value-lo, value-hi)
###################################################
## Channel Mode Messages (Continuous Controller)
## They share a status byte.
## The controller makes the difference here
# High resolution continuous controllers (MSB)
BANK_SELECT = 0x00
MODULATION_WHEEL = 0x01
BREATH_CONTROLLER = 0x02
FOOT_CONTROLLER = 0x04
PORTAMENTO_TIME = 0x05
DATA_ENTRY = 0x06
CHANNEL_VOLUME = 0x07
BALANCE = 0x08
PAN = 0x0A
EXPRESSION_CONTROLLER = 0x0B
EFFECT_CONTROL_1 = 0x0C
EFFECT_CONTROL_2 = 0x0D
GEN_PURPOSE_CONTROLLER_1 = 0x10
GEN_PURPOSE_CONTROLLER_2 = 0x11
GEN_PURPOSE_CONTROLLER_3 = 0x12
GEN_PURPOSE_CONTROLLER_4 = 0x13
# High resolution continuous controllers (LSB)
BANK_SELECT = 0x20
MODULATION_WHEEL = 0x21
BREATH_CONTROLLER = 0x22
FOOT_CONTROLLER = 0x24
PORTAMENTO_TIME = 0x25
DATA_ENTRY = 0x26
CHANNEL_VOLUME = 0x27
BALANCE = 0x28
PAN = 0x2A
EXPRESSION_CONTROLLER = 0x2B
EFFECT_CONTROL_1 = 0x2C
EFFECT_CONTROL_2 = 0x2D
GENERAL_PURPOSE_CONTROLLER_1 = 0x30
GENERAL_PURPOSE_CONTROLLER_2 = 0x31
GENERAL_PURPOSE_CONTROLLER_3 = 0x32
GENERAL_PURPOSE_CONTROLLER_4 = 0x33
# Switches
SUSTAIN_ONOFF = 0x40
PORTAMENTO_ONOFF = 0x41
SOSTENUTO_ONOFF = 0x42
SOFT_PEDAL_ONOFF = 0x43
LEGATO_ONOFF = 0x44
HOLD_2_ONOFF = 0x45
# Low resolution continuous controllers
SOUND_CONTROLLER_1 = 0x46 # (TG: Sound Variation; FX: Exciter On/Off)
SOUND_CONTROLLER_2 = 0x47 # (TG: Harmonic Content; FX: Compressor On/Off)
SOUND_CONTROLLER_3 = 0x48 # (TG: Release Time; FX: Distortion On/Off)
SOUND_CONTROLLER_4 = 0x49 # (TG: Attack Time; FX: EQ On/Off)
SOUND_CONTROLLER_5 = 0x4A # (TG: Brightness; FX: Expander On/Off)75 SOUND_CONTROLLER_6 (TG: Undefined; FX: Reverb OnOff)
SOUND_CONTROLLER_7 = 0x4C # (TG: Undefined; FX: Delay OnOff)
SOUND_CONTROLLER_8 = 0x4D # (TG: Undefined; FX: Pitch Transpose OnOff)
SOUND_CONTROLLER_9 = 0x4E # (TG: Undefined; FX: Flange/Chorus OnOff)
SOUND_CONTROLLER_10 = 0x4F # (TG: Undefined; FX: Special Effects OnOff)
GENERAL_PURPOSE_CONTROLLER_5 = 0x50
GENERAL_PURPOSE_CONTROLLER_6 = 0x51
GENERAL_PURPOSE_CONTROLLER_7 = 0x52
GENERAL_PURPOSE_CONTROLLER_8 = 0x53
PORTAMENTO_CONTROL = 0x54 # (PTC) (0vvvvvvv is the source Note number) (Detail)
EFFECTS_1 = 0x5B # (Ext. Effects Depth)
EFFECTS_2 = 0x5C # (Tremelo Depth)
EFFECTS_3 = 0x5D # (Chorus Depth)
EFFECTS_4 = 0x5E # (Celeste Depth)
EFFECTS_5 = 0x5F # (Phaser Depth)
DATA_INCREMENT = 0x60 # (0vvvvvvv is n/a; use 0)
DATA_DECREMENT = 0x61 # (0vvvvvvv is n/a; use 0)
NON_REGISTERED_PARAMETER_NUMBER = 0x62 # (LSB)
NON_REGISTERED_PARAMETER_NUMBER = 0x63 # (MSB)
REGISTERED_PARAMETER_NUMBER = 0x64 # (LSB)
REGISTERED_PARAMETER_NUMBER = 0x65 # (MSB)
# Channel Mode messages - (Detail)
ALL_SOUND_OFF = 0x78
RESET_ALL_CONTROLLERS = 0x79
LOCAL_CONTROL_ONOFF = 0x7A
ALL_NOTES_OFF = 0x7B
OMNI_MODE_OFF = 0x7C # (also causes ANO)
OMNI_MODE_ON = 0x7D # (also causes ANO)
MONO_MODE_ON = 0x7E # (Poly Off; also causes ANO)
POLY_MODE_ON = 0x7F # (Mono Off; also causes ANO)
###################################################
## System Common Messages, for all channels
SYSTEM_EXCLUSIVE = 0xF0
# 11110000 0iiiiiii 0ddddddd ... 11110111
MTC = 0xF1 # MIDI Time Code Quarter Frame
# 11110001
SONG_POSITION_POINTER = 0xF2
# 11110010 0vvvvvvv 0wwwwwww (lo-position, hi-position)
SONG_SELECT = 0xF3
# 11110011 0sssssss (songnumber)
#UNDEFINED = 0xF4
## 11110100
#UNDEFINED = 0xF5
## 11110101
TUNING_REQUEST = 0xF6
# 11110110
END_OFF_EXCLUSIVE = 0xF7 # terminator
# 11110111 # End of system exclusive
###################################################
## Midifile meta-events
SEQUENCE_NUMBER = 0x00 # 00 02 ss ss (seq-number)
TEXT = 0x01 # 01 len text...
COPYRIGHT = 0x02 # 02 len text...
SEQUENCE_NAME = 0x03 # 03 len text...
INSTRUMENT_NAME = 0x04 # 04 len text...
LYRIC = 0x05 # 05 len text...
MARKER = 0x06 # 06 len text...
CUEPOINT = 0x07 # 07 len text...
PROGRAM_NAME = 0x08 # 08 len text...
DEVICE_NAME = 0x09 # 09 len text...
MIDI_CH_PREFIX = 0x20 # MIDI channel prefix assignment (unofficial)
MIDI_PORT = 0x21 # 21 01 port, legacy stuff but still used
END_OF_TRACK = 0x2F # 2f 00
TEMPO = 0x51 # 51 03 tt tt tt (tempo in us/quarternote)
SMTP_OFFSET = 0x54 # 54 05 hh mm ss ff xx
TIME_SIGNATURE = 0x58 # 58 04 nn dd cc bb
KEY_SIGNATURE = 0x59 # ??? len text...
SPECIFIC = 0x7F # Sequencer specific event
FILE_HEADER = 'MThd'
TRACK_HEADER = 'MTrk'
###################################################
## System Realtime messages
## I don't supose these are to be found in midi files?!
TIMING_CLOCK = 0xF8
# undefined = 0xF9
SONG_START = 0xFA
SONG_CONTINUE = 0xFB
SONG_STOP = 0xFC
# undefined = 0xFD
ACTIVE_SENSING = 0xFE
SYSTEM_RESET = 0xFF
###################################################
## META EVENT, it is used only in midi files.
## In transmitted data it means system reset!!!
META_EVENT = 0xFF
# 11111111
###################################################
## Helper functions
def is_status(byte):
return (byte & 0x80) == 0x80 # 1000 0000
#===================== DataTypeConverters.py ========================#
"""
This module contains functions for reading and writing the special data types
that a midi file contains.
"""
"""
nibbles are four bits. A byte consists of two nibles.
hiBits==0xF0, loBits==0x0F Especially used for setting
channel and event in 1. byte of musical midi events
"""
def getNibbles(byte):
"""
Returns hi and lo bits in a byte as a tuple
Asserts byte <= 255
"""
return (byte >> 4 & 0xF, byte & 0xF)
def setNibbles(hiNibble, loNibble):
"""
returns byte with value set according to hi and lo bits
Asserts hiNibble <= 15 and loNibble <= 15
"""
return (hiNibble << 4) + loNibble
def readBew(value):
"Reads string as big endian word, (asserts len(value) in [1,2,4])"
return unpack('>%s' % {1:'B', 2:'H', 4:'L'}[len(value)], value)[0]
def writeBew(value, length):
"Write int as big endian formatted string, (asserts length in [1,2,4])"
return pack('>%s' % {1:'B', 2:'H', 4:'L'}[length], value)
"""
Variable Length Data (varlen) is a data format sprayed liberally throughout
a midi file. It can be anywhere from 1 to 4 bytes long.
If the 8'th bit is set in a byte another byte follows. The value is stored
in the lowest 7 bits of each byte. So max value is 4x7 bits = 28 bits.
"""
def readVar(value):
"""
Converts varlength format to integer. Just pass it 0 or more chars that
might be a varlen and it will only use the relevant chars.
use varLen(readVar(value)) to see how many bytes the integer value takes.
asserts len(value) >= 0
"""
sum = 0
for byte in unpack('%sB' % len(value), value):
sum = (sum << 7) + (byte & 0x7F)
if not 0x80 & byte: break # stop after last byte
return sum
def varLen(value):
"""
Returns the the number of bytes an integer will be when
converted to varlength
"""
if value <= 127:
return 1
elif value <= 16383:
return 2
elif value <= 2097151:
return 3
else:
return 4
def writeVar(value):
"Converts an integer to varlength format"
sevens = to_n_bits(value, varLen(value))
for i in range(len(sevens)-1):
sevens[i] = sevens[i] | 0x80
return fromBytes(sevens)
def to_n_bits(value, length=1, nbits=7):
"returns the integer value as a sequence of nbits bytes"
bytes = [(value >> (i*nbits)) & 0x7F for i in range(length)]
bytes.reverse()
return bytes
def toBytes(value):
"Turns a string into a list of byte values"
return unpack('%sB' % len(value), value)
def fromBytes(value):
"Turns a list of bytes into a string"
if not value:
return ''
return pack('%sB' % len(value), *value)
#=================== RawOutstreamFile.py ============================#
class RawOutstreamFile:
"""
Writes a midi file to disk.
"""
def __init__(self, outfile=''):
self.buffer = StringIO()
self.outfile = outfile
# native data reading functions
def writeSlice(self, str_slice):
"Reads the next text slice from the raw data, with length"
self.buffer.write(str_slice)
def writeBew(self, value, length=1):
"Writes a value to the file as big endian word"
self.writeSlice(writeBew(value, length))
def writeVarLen(self, value):
"Writes a variable length word to the file"
var = self.writeSlice(writeVar(value))
def write(self):
"Writes to disc"
if self.outfile:
if isinstance(self.outfile, StringType):
outfile = open(self.outfile, 'wb')
outfile.write(self.getvalue())
outfile.close()
else:
self.outfile.write(self.getvalue())
def getvalue(self):
return self.
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