add dump

examples/dump.ce

@@ -0,0 +1,73 @@
+/*
+ * MIDI Dump - Parse and print MIDI file contents
+ *
+ * Usage: cell run examples/dump.ce <midi_file>
+ */
+
+var io = use('cellfs')
+var midi = use('midi')
+
+if (length(args) < 1) {
+  log.console("Usage: cell run examples/dump.ce <midi_file>")
+  log.console("Example: cell run examples/dump.ce examples/invent8.mid")
+  $stop()
+}
+
+var midi_file = args[0]
+
+log.console("Loading MIDI: " + midi_file)
+var midi_blob = io.slurp(midi_file)
+if (!midi_blob) {
+  log.console("Error: Could not load MIDI file: " + midi_file)
+  $stop()
+}
+
+var song = midi.parse(midi_blob)
+
+log.console("Duration: " + text((song.duration_ms / 1000)) + "s")
+log.console("Notes: " + text(song.note_count))
+log.console("Events: " + text(length(song.events)))
+log.console("")
+
+var NOTE_NAMES = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']
+
+function note_name(key) {
+  var octave = floor(key / 12) - 1
+  var name = NOTE_NAMES[key % 12]
+  return name + text(octave)
+}
+
+function pad(s, n) {
+  var _s = text(s)
+  while (length(_s) < n) {
+    _s = _s + ' '
+  }
+  return _s
+}
+
+var events = song.events
+var i = 0
+var evt = null
+var line = ''
+
+for (i = 0; i < length(events); i++) {
+  evt = events[i]
+  line = pad(text(evt.time / 1000) + 's', 10)
+  line = line + 'ch=' + pad(evt.channel, 4)
+
+  if (evt.type == 'note_on') {
+    line = line + pad('note_on', 12) + note_name(evt.key) + ' vel=' + text(evt.velocity)
+  } else if (evt.type == 'note_off') {
+    line = line + pad('note_off', 12) + note_name(evt.key)
+  } else if (evt.type == 'control') {
+    line = line + pad('control', 12) + 'cc=' + text(evt.control) + ' val=' + text(evt.value)
+  } else if (evt.type == 'program') {
+    line = line + pad('program', 12) + 'preset=' + text(evt.program)
+  } else if (evt.type == 'pitch_bend') {
+    line = line + pad('pitch_bend', 12) + 'val=' + text(evt.pitch_bend)
+  } else if (evt.type == 'tempo') {
+    line = line + pad('tempo', 12) + 'bpm=' + text(evt.tempo)
+  }
+
+  log.console(line)
+}