public static IEnumerable<Track> ParseMidi(string fileName)
{
var tracks = new List<Track>();
var file = new MidiFile(fileName);
var tempo = 120;
for(var trackNumber = 0; trackNumber < file.Tracks; ++trackNumber)
{
var events = file.Events[trackNumber];
var tempoEvent = events.FirstOrDefault(c => c is TempoEvent) as TempoEvent;
if(tempoEvent != null)
{
tempo = (int)tempoEvent.Tempo;
}
}
var channel = 0;
for(var trackNumber = 0; trackNumber < file.Tracks; ++trackNumber, ++channel)
{
var phrases = new List<Phrase>();
var events = file.Events[trackNumber];
var path = events.FirstOrDefault(c => c is PatchChangeEvent) as PatchChangeEvent;
if(path != null && PatchChangeEvent.GetPatchName(path.Patch) == "Steel Drums")
{
continue;
}
var mediaPatch = PatchChangeEvent.GetPatchName(path?.Patch ?? 0)
.IndexOf("bass", StringComparison.InvariantCultureIgnoreCase) != -1
? MediaPatch.Bass
: MediaPatch.CleanGuitar;
var notes =
events.OfType<NoteOnEvent>().GroupBy(c => c.AbsoluteTime);
long lastTime = 0;
foreach(var noteCollection in notes)
{
if(noteCollection.Key - lastTime > 0)
{
var pauseTime = noteCollection.Key - lastTime;
phrases.Add(new Phrase(pauseTime / WholeNoteDuration));
}
var duration = noteCollection.Max(c => c.NoteLength);
var phrase = new Phrase
{
Duration = duration / WholeNoteDuration,
Notes = noteCollection.Select(c => Note.FromId(c.NoteNumber)).ToArray()
};
lastTime = noteCollection.Key + duration;
phrases.Add(phrase);
}
tracks.Add(new Track
{
Tempo = tempo,
Patch = mediaPatch,
Phrases = phrases.ToArray(),
Channel = channel
});
}
return tracks;
}
private ISampleProvider CreateSampleProvider(Phrase phrase, int offset, bool letRingPhrase)
{
if(phrase.Notes?.Any() ?? false)
{
var phraseDuration = phrase.GetPhraseSeconds(Tempo);
var additionalDuration = LetRingEnabled || letRingPhrase
? CurrentLetRingFadeOut
: 0;
var sampleProviders = phrase.Notes.Select(n => MediaBank.GetMedia(n)?.ToSampleProvider())
.Where(s => s != null).ToArray();
if(sampleProviders.Any())
{
var phraseSampleProvider =
new FadeOutSampleProvider(sampleProviders.Length > 1
? new DelayedMixingSampleProvider(sampleProviders, DefaultChordNotesDelay, false)
: sampleProviders.Single(),
phraseDuration + additionalDuration, DefaultFadeOutTime);
if(offset > 0)
{
return new OffsetSampleProvider(phraseSampleProvider)
{
DelayBySamples = offset
};
}
return phraseSampleProvider;
}
}
return null;
}
public static Track ParseString(string songStr)
{
var phrases = new List<Phrase>();
if(!string.IsNullOrWhiteSpace(songStr))
{
var noteModifier = PlayingCommand.None;
foreach(var token in songStr.Split(new[] {' '}, StringSplitOptions.RemoveEmptyEntries))
{
if(token.StartsWith("=")) //command
{
var command = new Phrase(PlayingCommand.None);
switch(token)
{
case "=LROn=":
command.Command = PlayingCommand.LetItRingOn;
break;
case "=LROff=":
command.Command = PlayingCommand.LetItRingOff;
break;
case "=LRw=":
command.Command = PlayingCommand.LetRingWhole;
break;
case "=LRh=":
command.Command = PlayingCommand.LetRingHalf;
break;
case "=LRq=":
command.Command = PlayingCommand.LetRingQuarter;
break;
case "=LR=":
noteModifier = PlayingCommand.LetRingNotes;
continue;
default:
throw new Exception($"Unknown command: {token}");
}
phrases.Add(command);
}
else
{
try
{
var dots = token.Count(c => c == '.');
var duration = token[token.Length - 1 - dots];
var phraseDuration = Durations.ContainsKey(duration) ? Durations[duration] : Durations['w'];
if(dots > 0)
{
var tempDuration = phraseDuration;
for(var i = 0; i < dots; i++)
{
tempDuration /= 2;
phraseDuration += tempDuration;
}
}
var notesString = token.Substring(0, token.Length - 1 - dots);
var notes =
notesString.Split(new[] {'_'}, StringSplitOptions.RemoveEmptyEntries)
.Select(Note.FromString);
var phrase = new Phrase(phraseDuration, notes.Distinct().ToArray()) {Command = noteModifier};
noteModifier = PlayingCommand.None;
phrases.Add(phrase);
}
catch(Exception)
{
throw new Exception($"Unable to parse phrase: {token}");
}
}
}
}
return new Track
{
Patch = MediaPatch.CleanGuitar,
Phrases = phrases,
Tempo = 60,
Channel = 0
};
}
