/// <summary>
/// Create percussion sounds for the detected meter
/// </summary>
/// <param name="midi"></param>
/// <param name="prolongSustainedNotes"></param>
/// <param name="volume"></param>
public static void AddBeats(Model midi, bool prolongSustainedNotes = false, int volume = 127)
{
var channel = midi.Tracks[0].Channels[Channel.PercussionChannelNumber];
var beatEvents = midi.EventsOfType <BeatEvent>().OrderBy(b => b.AbsoluteRealTime);
foreach (var beat in beatEvents)
{
var length = TimeSpan.FromMilliseconds(beat.Length.TotalMilliseconds * 0.25);
var note = new NoteOn
{
ChannelNumber = Channel.PercussionChannelNumber,
NoteNumber = beat.Level == 0 ? (byte)36 : (byte)44,
Volume = beat.Level == 2 ? (byte)(0.75 * volume) : (byte)volume,
AbsoluteRealTime = beat.AbsoluteRealTime,
AbsoluteTime = beat.AbsoluteTime,
RealTimeLength = length,
End = beat.AbsoluteRealTime + length
};
channel.Events.Add(note);
}
var collector = new VolumeChangeCollector(midi);
collector.DetermineVolumes();
if (prolongSustainedNotes)
{
var sustainer = new Sustainer(midi);
sustainer.ProlongSustainedNotes();
}
}
// If the meter is already detected, normalize it to 100 BPM
public static void Normalize(Model midi, bool prolongSustainedNotes = false)
{
var beatLength = 600;
var events = midi.Events().OrderBy(k => k.AbsoluteRealTime).GetEnumerator();
var normalizedTime = TimeSpan.Zero;
if (!events.MoveNext())
{
throw new Exception("no events");
}
var e = events.Current;
var beatsCopy = midi.EventsOfType <BeatEvent>().OrderBy(b => b.AbsoluteRealTime).Select(b => new BeatEvent {
AbsoluteRealTime = b.AbsoluteRealTime, Length = b.Length
});
foreach (var beat in beatsCopy)
{
while (e != null && e.AbsoluteRealTime < beat.AbsoluteRealTime + beat.Length)
{
var delta = (e.AbsoluteRealTime - beat.AbsoluteRealTime).TotalMilliseconds * beatLength / beat.Length.TotalMilliseconds;
e.AbsoluteRealTime = normalizedTime + TimeSpan.FromMilliseconds(delta);
if (!events.MoveNext())
{
break;
}
e = events.Current;
}
normalizedTime += TimeSpan.FromMilliseconds(beatLength);
}
foreach (var beat in midi.EventsOfType <BeatEvent>())
{
beat.Length = TimeSpan.FromMilliseconds(beatLength);
}
events.Dispose();
TimeCalculator.CreateNoteLengths(midi);
var collector = new VolumeChangeCollector(midi);
collector.DetermineVolumes();
if (prolongSustainedNotes)
{
var sustainer = new Sustainer(midi);
sustainer.ProlongSustainedNotes();
}
}
public static Model Parse(string filename, bool computeNoteLenghts = true, bool computePitchBends = true,
bool computeRealVolumes = true, bool determineInstruments = false, bool normalizeMetre = false,
bool prolongSustainedNotes = false, bool showBeats = false, bool analyzeKeys = false,
bool analyzeChords = false, bool playChords = false, bool discretizeBends = false, Tone?transposeTo = null)
{
if (playChords)
{
analyzeChords = true;
}
if (analyzeChords)
{
analyzeKeys = true;
}
if (discretizeBends)
{
computePitchBends = true;
}
if (transposeTo != null)
{
analyzeKeys = true;
}
var midi = new Model();
using (var reader = new MidiBigEndianReader(File.Open(filename, FileMode.Open)))
{
ParseHeaderChunk(reader, midi);
foreach (var track in midi.Tracks)
{
ParseTrackChunk(reader, track);
}
if (computeNoteLenghts || normalizeMetre || showBeats)
{
TimeCalculator.ComputeRealTimes(midi);
TimeCalculator.CreateNoteLengths(midi);
}
midi.Length = midi.EventsOfType <EndOfTrack>().Max(e => e.AbsoluteRealTime);
if (computeRealVolumes || normalizeMetre || showBeats)
{
var collector = new VolumeChangeCollector(midi);
collector.DetermineVolumes();
}
if (prolongSustainedNotes || normalizeMetre || showBeats)
{
var sustainer = new Sustainer(midi);
sustainer.ProlongSustainedNotes();
}
if (normalizeMetre)
{
Normalizer.CalculateMetre(midi);
Normalizer.Normalize(midi, prolongSustainedNotes);
}
else if (showBeats)
{
Normalizer.CalculateMetre(midi);
Normalizer.AddBeats(midi, prolongSustainedNotes);
}
if (computePitchBends)
{
PitchBendCalculator.JoinPitchBends(midi);
PitchBendCalculator.DeterminePitchRanges(midi);
if (discretizeBends)
{
PitchBendCalculator.DiscretizeBends(midi);
}
}
if (determineInstruments)
{
var collector = new InstrumentChangeCollector(midi);
collector.DetermineInstruments();
}
if (analyzeKeys)
{
if (!normalizeMetre && !showBeats)
{
Normalizer.CalculateMetre(midi);
}
if (midi.EventsOfType <KeySignature>().Any(k => k.Key.Tone != Tone.C || k.Key.Scale != Scale.Major))
{
midi.Key = midi.EventsOfType <KeySignature>().First().Key;
midi.IsKeyFoundByMidiItself = true;
}
else
{
MLKeyFinder.DetectKey(midi);
midi.IsKeyFoundByMidiItself = false;
}
}
if (analyzeChords)
{
var analyzer = new ChordAnalyzer(midi);
analyzer.Analyze();
if (playChords)
{
analyzer.AddChordNotesToModel();
}
}
if (transposeTo != null)
{
Transposer.Transpose(midi, (Tone)transposeTo);
}
ChannelPlayabilityChecker.Check(midi);
}
return(midi);
}
