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Diffstat (limited to 'mkiv.py')
| -rw-r--r-- | mkiv.py | 156 |
1 files changed, 156 insertions, 0 deletions
@@ -0,0 +1,156 @@ +''' +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)) |