Python aifc.py sampler metadata support

aifc.diff

296d295
<         self._loops = []
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<             elif chunkname == 'INST':
<                 self._readinst(chunk)    
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<     def getinst(self):
<         if len(self._loops) == 0:
<             return None
<         return self._loops
< 
< 
519,552d509
<     
<     def _readinst(self, chunk):
<         baseNote = struct.unpack('B',chunk.read(1))[0]
<         detune = struct.unpack('B',chunk.read(1))[0]
<         lowNote = struct.unpack('B',chunk.read(1))[0]
<         highNote = struct.unpack('B',chunk.read(1))[0]
<         lowVelocity = struct.unpack('B',chunk.read(1))[0]
<         highVelocity = struct.unpack('B',chunk.read(1))[0]
<         gain = _read_short(chunk)
<         # two loops
<         sustain_loop_playmode = _read_short(chunk)
<         sustain_marker_id_start = _read_short(chunk)
<         sustain_marker_id_end = _read_short(chunk)
<         release_loop_playmode = _read_short(chunk)
<         release_marker_id_start = _read_short(chunk)
<         release_marker_id_end = _read_short(chunk)
<         self._loops.append({
<           "baseNote":baseNote,
<           "detune":detune,
<           "lowNote":lowNote,
<           "highNote":highNote,
<           "lowVelocity":lowVelocity,
<           "highVelocity":highVelocity,
<           "gain":gain,
<           "sustain_loop":{
<             "playmode":sustain_loop_playmode,
<             "marker_id_start":sustain_marker_id_start,
<             "marker_id_end":sustain_marker_id_end},
<           "release_loop":{
<             "playmode":release_loop_playmode,
<             "marker_id_start":release_marker_id_start,
<             "marker_id_end":release_marker_id_end},
<           })
< 
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<         print "inst      =", f.getinst()
<         print "mark      =", f.getmarkers()