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'''
itl_chorus -- ITL Chorus Suite
mkiv -- Make Intervals
This simple script (using python-midi) reads a MIDI file and makes an interval
(.iv) file (actually XML) that contains non-overlapping notes.
TODO:
-Reserve channels by track
-Reserve channels by MIDI channel
-Pitch limits for channels
-MIDI Control events
'''
import xml.etree.ElementTree as ET
import midi
import sys
import os
pat = midi.read_midifile(sys.argv[1])
iv = ET.Element('iv')
iv.set('version', '1')
iv.set('src', os.path.basename(sys.argv[1]))
##### Merge events from all tracks into one master list, annotated with track and absolute times #####
print 'Merging events...'
class MergeEvent(object):
__slots__ = ['ev', 'tidx', 'abstime']
def __init__(self, ev, tidx, abstime):
self.ev = ev
self.tidx = tidx
self.abstime = abstime
def __repr__(self):
return '<ME %r in %d @%f>'%(self.ev, self.tidx, self.abstime)
events = []
bpm_at = {0: 120}
for tidx, track in enumerate(pat):
abstime = 0
absticks = 0
for ev in track:
if isinstance(ev, midi.SetTempoEvent):
absticks += ev.tick
bpm_at[absticks] = ev.bpm
else:
if isinstance(ev, midi.NoteOnEvent) and ev.velocity == 0:
ev.__class__ = midi.NoteOffEvent #XXX Oww
bpm = filter(lambda pair: pair[0] <= absticks, bpm_at.items())[-1][1]
abstime += (60.0 * ev.tick) / (bpm * pat.resolution)
absticks += ev.tick
events.append(MergeEvent(ev, tidx, abstime))
print 'Sorting events...'
events.sort(key = lambda ev: ev.abstime)
##### Use merged events to construct a set of streams with non-overlapping durations #####
print 'Generating streams...'
class DurationEvent(MergeEvent):
__slots__ = ['duration']
def __init__(self, me, dur):
MergeEvent.__init__(self, me.ev, me.tidx, me.abstime)
self.duration = dur
class NoteStream(object):
__slots__ = ['history', 'active']
def __init__(self):
self.history = []
self.active = None
def IsActive(self):
return self.active is not None
def Activate(self, mev):
self.active = mev
def Deactivate(self, mev):
self.history.append(DurationEvent(self.active, mev.abstime - self.active.abstime))
self.active = None
def WouldDeactivate(self, mev):
if not self.IsActive():
return False
return mev.ev.pitch == self.active.ev.pitch and mev.tidx == self.active.tidx
notestreams = []
auxstream = []
for mev in events:
if isinstance(mev.ev, midi.NoteOnEvent):
for stream in notestreams:
if not stream.IsActive():
stream.Activate(mev)
break
else:
stream = NoteStream()
notestreams.append(stream)
stream.Activate(mev)
elif isinstance(mev.ev, midi.NoteOffEvent):
for stream in notestreams:
if stream.WouldDeactivate(mev):
stream.Deactivate(mev)
break
else:
print 'WARNING: Did not match %r with any stream deactivation.'%(mev,)
else:
auxstream.append(mev)
lastabstime = events[-1].abstime
for ns in notestreams:
if not ns:
print 'WARNING: Active notes at end of playback.'
ns.Deactivate(MergeEvent(ns.active, ns.active.tidx, lastabstime))
print 'Generated %d streams'%(len(notestreams),)
##### Write to XML and exit #####
ivmeta = ET.SubElement(iv, 'meta')
ivbpms = ET.SubElement(ivmeta, 'bpms')
abstime = 0
prevticks = 0
prev_bpm = 120
for absticks, bpm in sorted(bpm_at.items(), key = lambda pair: pair[0]):
abstime += ((absticks - prevticks) * 60.0) / (prev_bpm * pat.resolution)
prevticks = absticks
ivbpm = ET.SubElement(ivbpms, 'bpm')
ivbpm.set('bpm', str(bpm))
ivbpm.set('ticks', str(absticks))
ivbpm.set('time', str(abstime))
ivstreams = ET.SubElement(iv, 'streams')
for ns in notestreams:
ivns = ET.SubElement(ivstreams, 'stream')
ivns.set('type', 'ns')
for note in ns.history:
ivnote = ET.SubElement(ivns, 'note')
ivnote.set('pitch', str(note.ev.pitch))
ivnote.set('vel', str(note.ev.velocity))
ivnote.set('time', str(note.abstime))
ivnote.set('dur', str(note.duration))
ivaux = ET.SubElement(ivstreams, 'stream')
ivaux.set('type', 'aux')
fw = midi.FileWriter()
fw.RunningStatus = None # XXX Hack
for mev in auxstream:
ivev = ET.SubElement(ivaux, 'ev')
ivev.set('time', str(mev.abstime))
ivev.set('data', repr(fw.encode_midi_event(mev.ev)))
print 'Done.'
open(os.path.splitext(os.path.basename(sys.argv[1]))[0]+'.iv', 'w').write(ET.tostring(iv))
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