1 files changed, 117 insertions, 0 deletions
diff --git a/downsamp.py b/downsamp.py
new file mode 100644
index 0000000..f7a0255
--- /dev/null
+++ b/downsamp.py
@@ -0,0 +1,117 @@
+from xml.etree import ElementTree as ET
+import optparse
+import os
+
+parser = optparse.OptionParser()
+parser.add_option('-f', '--frequency', dest='frequency', type='float', help='How often to switch between active streams')
+parser.set_defaults(frequency=0.016)
+options, args = parser.parse_args()
+
+class Note(object):
+    def __init__(self, time, dur, pitch, ampl):
+        self.time = time
+        self.dur = dur
+        self.pitch = pitch
+        self.ampl = ampl
+
+for fname in args:
+    try:
+        iv = ET.parse(fname).getroot()
+    except IOError:
+        import traceback
+        traceback.print_exc()
+        print fname, ': Bad file'
+        continue
+
+    print '----', fname, '----'
+
+    notestreams = iv.findall("./streams/stream[@type='ns']")
+    print len(notestreams), 'notestreams'
+
+    print 'Loading all events...'
+
+    evs = []
+
+    dur = 0.0
+
+    for ns in notestreams:
+        for note in ns.findall('note'):
+            n = Note(
+                float(note.get('time')),
+                float(note.get('dur')),
+                float(note.get('pitch')),
+                float(note.get('ampl', float(note.get('vel', 127.0)) / 127.0)),
+            )
+            evs.append(n)
+            if n.time + n.dur > dur:
+                dur = n.time + n.dur
+
+    print len(evs), 'events'
+    print dur, 'duration'
+
+    print 'Scheduling events...'
+
+    sched = {}
+
+    t = 0.0
+    i = 0
+    while t <= dur:
+        nextt = t + options.frequency
+        #print '-t', t, 'nextt', nextt
+
+        evs_now = [n for n in evs if n.time <= t and t < n.time + n.dur]
+        if evs_now:
+            holding = False
+            count = 0
+            while count < len(evs_now):
+                selidx = (count + i) % len(evs_now)
+                sel = evs_now[selidx]
+                sched[t] = (sel.pitch, sel.ampl)
+                if sel.time + sel.dur >= nextt:
+                    holding = True
+                    break
+                t = sel.time + sel.dur
+                count += 1
+            if not holding:
+                sched[t] = (0, 0)
+        else:
+            sched[t] = (0, 0)
+
+        t = nextt
+        i += 1
+
+    print len(sched), 'events scheduled'
+
+    print 'Writing out schedule...'
+
+    newiv = ET.Element('iv')
+    newiv.append(iv.find('meta'))
+    newivstreams = ET.SubElement(newiv, 'streams')
+    newivstream = ET.SubElement(newivstreams, 'stream', type='ns')
+
+    prevt = None
+    prevev = None
+    for t, ev in sorted(sched.items(), key=lambda pair: pair[0]):
+        if prevt is not None:
+            if prevev[0] != 0:
+                ET.SubElement(newivstream, 'note',
+                        pitch = str(prevev[0]),
+                        ampl = str(prevev[1]),
+                        time = str(prevt),
+                        dur = str(t - prevt),
+                )
+        prevev = ev
+        prevt = t
+
+    t = dur
+    if prevev[0] != 0:
+        ET.SubElement(newivstream, 'note',
+                pitch = str(prevev[0]),
+                ampl = str(prevev[1]),
+                time = str(prevt),
+                dur = str(t - prevt),
+        )
+
+    print 'Done.'
+    txt = ET.tostring(newiv, 'UTF-8')
+    open(os.path.splitext(os.path.basename(fname))[0]+'.downsampled.iv', 'wb').write(txt)