--- /dev/null
+# This file is part of LilyPond, the GNU music typesetter.
+#
+# Copyright (C) 2001--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
+# Jan Nieuwenhuizen <janneke@gnu.org>
+#
+#
+# LilyPond 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.
+#
+# LilyPond 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 LilyPond. If not, see <http://www.gnu.org/licenses/>.
+
+# import midi
+# s = open ("s.midi").read ()
+# midi.parse_track (s)
+# midi.parse (s)
+#
+#
+# returns a MIDI file as the tuple
+#
+# ((format, division), TRACKLIST) # division (>0) = TPQN*4
+# # or (<0) TBD
+#
+# each track is an EVENTLIST, where EVENT is
+#
+# (time, (type, ARG1, [ARG2])) # time = cumulative delta time
+ # MIDI event:
+ # type = MIDI status+channel >= x80
+ # META-event = xFF:
+ # type = meta-event type <= x7F
+ # ARG1 = length
+ # ARG2 = data
+
+import array
+import struct
+
+class error (Exception): pass
+
+# class warning (Exception): pass
+
+def _add_constants ():
+ channelVoiceMessages = (
+ (0x80, "NOTE_OFF"),
+ (0x90, "NOTE_ON"),
+ (0xA0, "POLYPHONIC_KEY_PRESSURE"),
+ (0xB0, "CONTROLLER_CHANGE"),
+ (0xC0, "PROGRAM_CHANGE"),
+ (0xD0, "CHANNEL_KEY_PRESSURE"),
+ (0xE0, "PITCH_BEND"),
+ )
+ channelModeMessages = (
+ (0x78, "ALL_SOUND_OFF"),
+ (0x79, "RESET_ALL_CONTROLLERS"),
+ (0x7A, "LOCAL_CONTROL"),
+ (0x7B, "ALL_NOTES_OFF"),
+ (0x7C, "OMNI_MODE_OFF"),
+ (0x7D, "OMNI_MODE_ON"),
+ (0x7E, "MONO_MODE_ON"),
+ (0x7F, "POLY_MODE_ON"),
+ )
+ metaEvents = (
+ (0x00, "SEQUENCE_NUMBER"),
+ (0x01, "TEXT_EVENT"),
+ (0x02, "COPYRIGHT_NOTICE"),
+ (0x03, "SEQUENCE_TRACK_NAME"),
+ (0x04, "INSTRUMENT_NAME"),
+ (0x05, "LYRIC"), #renamed LYRIC_DISPLAY MIDI RP-26
+ (0x06, "MARKER"),
+ (0x07, "CUE_POINT"),
+ (0x08, "PROGRAM_NAME"), #added MIDI RP-19
+ (0X09, "DEVICE_NAME"), #added MIDI RP-19
+ (0x20, "MIDI_CHANNEL_PREFIX"),
+ (0x21, "MIDI_PORT"),
+ (0x2F, "END_OF_TRACK"),
+ (0x51, "SET_TEMPO"),
+ (0x54, "SMTPE_OFFSET"),
+ (0x58, "TIME_SIGNATURE"),
+ (0x59, "KEY_SIGNATURE"),
+ (0x60, "XMF_PATCH_TYPE_PREFIX"), #added MIDI RP-32
+ (0x7F, "SEQUENCER_SPECIFIC_META_EVENT"),
+ (0xFF, "META_EVENT"),
+ )
+ globals().update((desc, msg) for msg, desc in
+ channelVoiceMessages + channelModeMessages + metaEvents)
+
+_add_constants ()
+
+def _get_variable_length_number (nextbyte, getbyte):
+ sum = 0
+ while nextbyte >= 0x80:
+ sum = (sum + (nextbyte & 0x7F)) << 7
+ nextbyte = getbyte()
+ return sum + nextbyte
+
+def _first_command_is_repeat(status, nextbyte, getbyte):
+ raise error('the first midi command in the track is a repeat')
+
+def _read_two_bytes (status, nextbyte, getbyte):
+ return status, nextbyte
+
+def _read_three_bytes (status, nextbyte, getbyte):
+ return status, nextbyte, getbyte()
+
+def _read_string (nextbyte, getbyte):
+ length = _get_variable_length_number (nextbyte, getbyte)
+ return ''.join(chr(getbyte()) for i in xrange(length))
+
+def _read_f0_byte (status, nextbyte, getbyte):
+ if status == 0xff:
+ return status, nextbyte, _read_string(getbyte(), getbyte)
+ return status, _read_string(nextbyte, getbyte)
+
+_read_midi_event = (
+ _first_command_is_repeat, # 0
+ None, # 10
+ None, # 20
+ None, # 30
+ None, # 40
+ None, # 50
+ None, # 60 data entry???
+ None, # 70 all notes off???
+ _read_three_bytes, # 80 note off
+ _read_three_bytes, # 90 note on
+ _read_three_bytes, # a0 poly aftertouch
+ _read_three_bytes, # b0 control
+ _read_two_bytes, # c0 prog change
+ _read_two_bytes, # d0 ch aftertouch
+ _read_three_bytes, # e0 pitchwheel range
+ _read_f0_byte, # f0
+)
+
+def _parse_track_body (data, clocks_max):
+ # This seems to be the fastest way of getting bytes in order as integers.
+ dataiter = iter(array.array('B', data))
+ getbyte = dataiter.next
+
+ time = 0
+ status = 0
+ try:
+ for nextbyte in dataiter:
+ time += _get_variable_length_number (nextbyte, getbyte)
+ if clocks_max and time > clocks_max:
+ break
+ nextbyte = getbyte()
+ if nextbyte >= 0x80:
+ status = nextbyte
+ nextbyte = getbyte()
+ yield time, _read_midi_event[status >> 4] (status, nextbyte, getbyte)
+ except StopIteration:
+ # If the track ended just before the start of an event, the for loop
+ # will exit normally. If it ends anywhere else, we end up here.
+ print len(list(dataiter))
+ raise error('a track ended in the middle of a MIDI command')
+
+def _parse_hunk (data, pos, type, magic):
+ if data[pos:pos+4] != magic:
+ raise error ('expected %r, got %r' % (magic, data[pos:pos+4]))
+ try:
+ length, = struct.unpack ('>I', data[pos+4:pos+8])
+ except struct.error:
+ raise error ('the %s header is truncated (may be an incomplete download)' % type)
+ endpos = pos + 8 + length
+ data = data[pos+8:endpos]
+ if len(data) != length:
+ raise error('the %s is truncated (may be an incomplete download)' % type)
+ return data, endpos
+
+def _parse_tracks (midi, pos, num_tracks, clocks_max):
+ if num_tracks > 256:
+ raise error('too many tracks: %d' % num_tracks)
+ for i in xrange(num_tracks):
+ trackdata, pos = _parse_hunk (midi, pos, 'track', 'MTrk')
+ yield list (_parse_track_body (trackdata, clocks_max))
+ # if pos < len(midi):
+ # warn
+
+def parse_track (track, clocks_max=None):
+ track_body, end = _parse_hunk (track, 0, 'track', 'MTrk')
+ # if end < len(track):
+ # warn
+ return list (_parse_track_body (track_body, clocks_max))
+
+def parse (midi, clocks_max=None):
+ header, first_track_pos = _parse_hunk(midi, 0, 'file', 'MThd')
+ try:
+ format, num_tracks, division = struct.unpack ('>3H', header[:6])
+ except struct.error:
+ raise error('the file header is too short')
+# if division < 0:
+# raise error ('cannot handle non-metrical time')
+ tracks = list (_parse_tracks (midi, first_track_pos, num_tracks, clocks_max))
+ return (format, division*4), tracks