public static Section ReadMidi(string filepath)
{
var midi = MidiFile.Read(filepath);
var section = new Section(Path.GetFileNameWithoutExtension(filepath));
foreach (var midiChunk in midi.Chunks)
{
if (!(midiChunk is TrackChunk chunk))
{
continue;
}
var phrase = new Phrase();
var programEvent = chunk.Events.OfType <ProgramChangeEvent>().FirstOrDefault();
if (programEvent != null)
{
phrase.Instrument = (MidiInstrument)(int)programEvent.ProgramNumber;
}
var nameEvent = chunk.Events.OfType <SequenceTrackNameEvent>().FirstOrDefault();
if (nameEvent != null)
{
phrase.Description = nameEvent.Text.Replace("\0", "");
}
var tempoEvent = chunk.Events.OfType <SetTempoEvent>().FirstOrDefault();
if (tempoEvent != null)
{
phrase.Bpm = Math.Round(1M / (tempoEvent.MicrosecondsPerQuarterNote / 60M) * 1000000M, 2);
}
var panEvent = chunk.Events
.OfType <ControlChangeEvent>().FirstOrDefault(x => x.ControlNumber == (SevenBitNumber)10);
if (panEvent != null)
{
phrase.Panning = (panEvent.ControlValue / 126M * 2M) - 1M;
}
using (var manager = new TimedEventsManager(chunk.Events))
{
phrase.Elements = manager.Events
.Where(x => x.Event is NoteOnEvent)
.Select(GetNewPhraseElement)
.ToList();
var offNotes = manager.Events
.Where(x => x.Event is NoteOffEvent)
.Select(x => new Tuple <decimal, int>(Convert.ToDecimal(x.Time) / 24M,
((NoteOffEvent)x.Event).NoteNumber - NoteOffset))
.ToList();
foreach (var element in phrase.Elements)
{
var offNote = offNotes
.FirstOrDefault(x => x.Item1 > element.Position && x.Item2 == element.Note);
if (offNote == null)
{
throw new ApplicationException("No off note found");
}
element.Duration = offNote.Item1 - element.Position;
}
}
phrase.IsDrums = chunk.Events.OfType <NoteOnEvent>().Any(x => x.Channel == (FourBitNumber)DrumChannel);
phrase.PhraseLength = NoteHelper.GetTotalDuration(phrase);
phrase.Elements = phrase.Elements.OrderBy(x => x.Position).ThenBy(x => x.Note).ToList();
section.Phrases.Add(phrase);
}
if (section.Phrases.Count == 0)
{
throw new ApplicationException("Invalid Midi File");
}
// remove blank tempo phrase
if (section.Phrases.Count > 1 &&
section.Phrases[0].PhraseLength == 0 &&
section.Phrases[0].Instrument == MidiInstrument.AcousticGrandPiano &&
!section.Phrases[0].IsDrums)
{
section.Phrases.RemoveAt(0);
}
return(section);
}
