def key_signature(self, sf, mi):
"""
sf: is a byte specifying the number of flats (-ve) or sharps
(+ve) that identifies the key signature (-7 = 7 flats, -1
= 1 flat, 0 = key of C, 1 = 1 sharp, etc).
mi: is a byte specifying a major (0) or minor (1) key.
"""
self.meta_slice(KEY_SIGNATURE, fromBytes([sf, mi]))
def tempo(self, value):
"""
value: 0-2097151
tempo in us/quarternote
(to calculate value from bpm: int(60,000,000.00 / BPM))
"""
hb, mb, lb = (value >> 16 & 0xff), (value >> 8 & 0xff), (value & 0xff)
self.meta_slice(TEMPO, fromBytes([hb, mb, lb]))
def pitch_bend(self, channel, value):
"""
channel: 0-15
value: 0-16383
"""
msb = (value >> 7) & 0xFF
lsb = value & 0xFF
slc = fromBytes([PITCH_BEND + channel, msb, lsb])
self.event_slice(slc)
def time_signature(self, nn, dd, cc, bb):
"""
nn: Numerator of the signature as notated on sheet music
dd: Denominator of the signature as notated on sheet music
The denominator is a negative power of 2: 2 = quarter
note, 3 = eighth, etc.
cc: The number of MIDI clocks in a metronome click
bb: The number of notated 32nd notes in a MIDI quarter note
(24 MIDI clocks)
"""
self.meta_slice(TIME_SIGNATURE, fromBytes([nn, dd, cc, bb]))
def end_of_track(self):
"""
Writes the track to the buffer.
"""
raw = self.raw_out
raw.writeSlice(TRACK_HEADER)
track_data = self._current_track_buffer.getvalue()
# wee need to know size of track data.
eot_slice = writeVar(self.rel_time()) + fromBytes([META_EVENT, END_OF_TRACK, 0])
raw.writeBew(len(track_data)+len(eot_slice), 4)
# then write
raw.writeSlice(track_data)
raw.writeSlice(eot_slice)
def smtp_offset(self, hour, minute, second, frame, framePart):
"""
hour,
minute,
second: 3 bytes specifying the hour (0-23), minutes (0-59) and
seconds (0-59), respectively. The hour should be
encoded with the SMPTE format, just as it is in MIDI
Time Code.
frame: A byte specifying the number of frames per second (one
of : 24, 25, 29, 30).
framePart: A byte specifying the number of fractional frames,
in 100ths of a frame (even in SMPTE-based tracks
using a different frame subdivision, defined in the
MThd chunk).
"""
self.meta_slice(SMTP_OFFSET,
fromBytes([hour, minute, second, frame, framePart]))
def meta_event(self, meta_type, data):
"""
Handles any undefined meta events
"""
self.meta_slice(meta_type, fromBytes(data))
def meta_slice(self, meta_type, data_slice):
"Writes a meta event"
slc = fromBytes([META_EVENT, meta_type]) + \
writeVar(len(data_slice)) + data_slice
self.event_slice(slc)
def song_select(self, songNumber):
"""
songNumber: 0-127
"""
self.event_slice(fromBytes([SONG_SELECT, songNumber]))