/// <summary>Parse a meta MIDI event from the data stream.</summary>
/// <param name="deltaTime">The previously parsed delta-time for this event.</param>
/// <param name="eventType">The previously parsed type of message we're expecting to find.</param>
/// <param name="data">The data stream from which to read the event information.</param>
/// <param name="pos">The position of the start of the event information.</param>
/// <returns>The parsed meta MIDI event.</returns>
private static MidiEvent ParseMetaEvent(long deltaTime, byte eventType, byte[] data, ref long pos)
{
try {
MidiEvent tempEvent = null;
// Create the correct meta event based on its meta event id/type
switch (eventType)
{
// Sequence number
case SequenceNumberMetaMidiEvent.MetaId:
pos++; // skip past the 0x02
int number = ((data[pos] << 8) | data[pos + 1]);
tempEvent = new SequenceNumberMetaMidiEvent(deltaTime, number);
pos += 2; // skip read values
break;
// Text events (copyright, lyrics, etc)
case TextMetaMidiEvent.MetaId:
tempEvent = new TextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case CopyrightTextMetaMidiEvent.MetaId:
tempEvent = new CopyrightTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case SequenceTrackNameTextMetaMidiEvent.MetaId:
tempEvent = new SequenceTrackNameTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case InstrumentTextMetaMidiEvent.MetaId:
tempEvent = new InstrumentTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case LyricTextMetaMidiEvent.MetaId:
tempEvent = new LyricTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case MarkerTextMetaMidiEvent.MetaId:
tempEvent = new MarkerTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case CuePointTextMetaMidiEvent.MetaId:
tempEvent = new CuePointTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case ProgramNameTextMetaMidiEvent.MetaId:
tempEvent = new ProgramNameTextMetaMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
case DeviceNameTextMidiEvent.MetaId:
tempEvent = new DeviceNameTextMidiEvent(deltaTime, ReadASCIIText(data, ref pos));
break;
// Channel prefix
case ChannelPrefixMetaMidiEvent.MetaId:
pos++; // skip 0x1
tempEvent = new ChannelPrefixMetaMidiEvent(deltaTime, data[pos]);
pos++; // skip read value
break;
// Port number
case MidiPortMetaMidiEvent.MetaId:
pos++; // skip 0x1
tempEvent = new MidiPortMetaMidiEvent(deltaTime, data[pos]);
pos++; // skip read value
break;
// End of track
case EndOfTrackMetaMidiEvent.MetaId:
pos++; // skip 0x0
tempEvent = new EndOfTrackMetaMidiEvent(deltaTime);
break;
// Tempo
case TempoMetaMidiEvent.MetaId:
pos++; // skip 0x3
int tempo = ((data[pos] << 16) | data[pos + 1] << 8 | data[pos + 2]);
tempEvent = new TempoMetaMidiEvent(deltaTime, tempo);
pos += 3;
break;
// SMPTE offset
case SMPTEOffsetMetaMidiEvent.MetaId:
pos++; // skip 0x5
tempEvent = new SMPTEOffsetMetaMidiEvent(deltaTime,
data[pos], data[pos + 1], data[pos + 2], data[pos + 3], data[pos + 4]);
pos += 5;
break;
// Time signature
case TimeSignatureMetaMidiEvent.MetaId:
pos++; // skip past 0x4
tempEvent = new TimeSignatureMetaMidiEvent(deltaTime,
data[pos], data[pos + 1], data[pos + 2], data[pos + 3]);
pos += 4;
break;
// Key signature
case KeySignatureMetaMidiEvent.MetaId:
pos++; // skip past 0x2
tempEvent = new KeySignatureMetaMidiEvent(deltaTime, (Key)data[pos], (Tonality)data[pos + 1]);
pos += 2;
break;
// Proprietary
case ProprietaryMetaMidiEvent.MetaId:
// Read in the variable length and that much data, then store it
long length = ReadVariableLength(data, ref pos);
byte[] propData = new byte[length];
Array.Copy(data, (int)pos, propData, 0, (int)length);
tempEvent = new ProprietaryMetaMidiEvent(deltaTime, propData);
pos += length;
break;
// An unknown meta event!
default:
// Read in the variable length and that much data, then store it
length = ReadVariableLength(data, ref pos);
byte[] unknownData = new byte[length];
Array.Copy(data, (int)pos, unknownData, 0, (int)length);
tempEvent = new UnknownMetaMidiEvent(deltaTime, eventType, unknownData);
pos += length;
break;
}
return(tempEvent);
}
// Something bad happened; wrap it in a parser exception
catch (Exception exc) { throw new MidiParserException("Unable to parse meta MIDI event.", exc, pos); }
}
void Output(OutputType type)
{
switch (type)
{
case OutputType.Midi:
/*List<MidiEvent> midiEvents = new List<MidiEvent> ();
*
* double max = 0;
* for (int i = 0; i < notes.Count; i++) {
* double d = notes[i].duration * 4;
* double t1 = notes[i].time * 4;
* double t2 = t1 + d;
* max = t2 > max ? t2 : max;
*
* NoteOnEvent note = new NoteOnEvent (Convert.ToInt64 (t1), 1, notes[i].noteNumber + 40, 127, Convert.ToInt32(d));
* midiEvents.Add (note);
* }
* MidiEvent endMarker = new NoteEvent (Convert.ToInt64(max), 1, MidiCommandCode.StopSequence, 0, 0);
* midiEvents.Add (endMarker);
*
* MidiEventCollection collection = new MidiEventCollection (0, 1);
* collection.AddTrack (midiEvents);
*
* MidiFile.Export ("C:/Users/Jonas/OneDrive/GIP/Proef/Output/midi.mid", collection);*/
MidiTrack track = new MidiTrack();
long maxTime = 0;
//string path = "C:/Users/Jonas/Desktop/result.txt";
double previousTime = 0;
for (int i = 0; i < notes.Count; i++)
{
string path = "C:/Users/Jonas/Desktop/result.txt";
File.AppendAllText(path, string.Format("{0} at {1}\n", DecodeNote(notes[i].noteNumber + 44, NoteNotation.Short), notes[i].time));
double d = 1;
double t1 = notes[i].time * 20 - previousTime;
double t2 = t1 + d;
if (t1 < 0)
{
continue;
}
previousTime = t2;
MidiEvent onEvent = new OnNoteVoiceMidiEvent(Convert.ToInt64(t1), 1, (byte)(44 + notes[i].noteNumber), 63);
MidiEvent offEvent = new OffNoteVoiceMidiEvent(Convert.ToInt64(t2), 1, (byte)(44 + notes[i].noteNumber), 0);
long t2long = (long)t2;
maxTime = (t2long > maxTime) ? t2long : maxTime;
track.Events.Add(onEvent);
track.Events.Add(offEvent);
}
MidiEvent endMarker = new EndOfTrackMetaMidiEvent(maxTime);
track.Events.Add(endMarker);
MidiSequence sequence = new MidiSequence(Format.Zero, 1000);
sequence.Tracks.Add(track);
FileStream stream = new FileStream("C:/Users/Jonas/OneDrive/GIP/Proef/Output/midi.mid", FileMode.OpenOrCreate);
sequence.Save(stream);
stream.Close();
break;
case OutputType.Audio:
double longest = 0;
for (int i = 0; i < notes.Count; i++)
{
double time = notes[i].time + notes[i].duration;
longest = Math.Max(time, longest);
}
double[] newSamples = new double[(int)Math.Ceiling(longest * rawAudio.sampleRate)];
for (int i = 0; i < notes.Count; i++)
{
int startIndex = (int)Math.Floor(notes[i].time * rawAudio.sampleRate);
int endIndex = (int)Math.Floor((notes[i].time + notes[i].duration) * rawAudio.sampleRate);
double freq = 110 * Math.Pow(1.059463094359295, notes[i].noteNumber);
double amp = notes[i].amplitude;
for (int j = startIndex; j < endIndex; j++)
{
double time = j * rawAudio.SampleLength + notes[i].time;
double value = Math.Sin(time * freq * 2 * Math.PI) * amp;
//double maxAmp = Math.Min (1, 5 * Math.Min (Math.Abs (time - notes[i].time), Math.Abs (time - (notes[i].time + notes[i].duration))));
newSamples[j] += value;
}
}
for (int i = 0; i < newSamples.Length; i++)
{
newSamples[i] = Math.Max(Math.Min(1, newSamples[i]), -1);
}
int avgSpread = 35;
double[] smoothSamples = new double[newSamples.Length - avgSpread];
for (int i = 0; i < newSamples.Length - avgSpread; i++)
{
double tot = 0;
for (int j = 0; j < avgSpread; j++)
{
tot += newSamples[i + j];
}
smoothSamples[i] = tot / avgSpread;
}
Song song = new Song(smoothSamples, rawAudio.channels, rawAudio.sampleRate);
// GIPIO.SaveSong (song, GIPIO.outputPath + "test.wav");
producedAudio = song;
break;
case OutputType.Wavelet:
pixels = new uint[allAmps.Count * allAmps[0].Length];
for (int x = 0; x < allAmps.Count; x++)
{
for (int y = 0; y < allAmps[0].Length; y++)
{
double i = allAmps[x][y];
// i *= 2;
i = Math.Min(1, i);
// double r = -2 * (i - 1.0) * (2 * (i - 1.0)) + 1;
// double g = -2 * (i - 0.5) * (2 * (i - 0.5)) + 1;
// double b = -2 * (i - 0.0) * (2 * (i - 0.0)) + 1;
double r, g, b;
r = g = b = i;
uint red = (uint)Math.Round(r * 255);
uint green = (uint)Math.Round(g * 255);
uint blue = (uint)Math.Round(b * 255);
int index = (allAmps[0].Length - y - 1) * allAmps.Count + x;
pixels[index] = (uint)((255 << 24) + (red << 16) + (green << 8) + blue);
}
}
DrawWavelet();
break;
}
}
