public override byte[] getEventData() // returns a raw byte array of this SysEx Event in the MIDI file
{
byte[] dataLength = VariableLength.ConvertToVariableLength(data.Length);
byte[] returnData = new byte[data.Length + 1 + dataLength.Length];
returnData[0] = sysexType;
Array.Copy(dataLength, 0, returnData, 1, dataLength.Length);
Array.Copy(data, 0, returnData, 1 + dataLength.Length, data.Length);
return(returnData);
}
public override byte[] getEventData() // returns a raw byte array of this META Event in the MIDI file
{
byte[] dataLength = VariableLength.ConvertToVariableLength(data.Length);
byte[] returnData = new byte[data.Length + 2 + dataLength.Length];
returnData[0] = 0xFF;
returnData[1] = metaType;
Array.Copy(dataLength, 0, returnData, 2, dataLength.Length);
Array.Copy(data, 0, returnData, 2 + dataLength.Length, data.Length);
return(returnData);
}
public static void saveToFile(string filePath, List <MidiTrack> midiTracks, ushort timeDivision)
{
Console.WriteLine("Saving MIDI to type 1 file...");
// first of all check if a file with the name already exists
if (File.Exists(filePath))
{
File.Delete(filePath);
}
FileStream midiFileStream = new FileStream(filePath, FileMode.Append, FileAccess.Write, FileShare.None);
BinaryWriter midiWriter = new BinaryWriter(midiFileStream);
Console.WriteLine("The new MIDI file has {0} tracks!", midiTracks.Count);
// first of all write MIDI header string
midiWriter.Write(Encoding.ASCII.GetBytes("MThd"));
// writer the header chunk length (=6)
midiWriter.Write(intToBigEndian(6));
// write the midi file type (=1)
midiWriter.Write(ushortToBigEndian(1));
// write the amount of tracks
midiWriter.Write(ushortToBigEndian((ushort)midiTracks.Count));
// write the time division
midiWriter.Write(ushortToBigEndian(timeDivision));
// finished writing the header, now do the tracks
long[] trackHeaderOffset = new long[midiTracks.Count];
long[] trackStartOffset = new long[midiTracks.Count];
long[] trackEndOffset = new long[midiTracks.Count];
for (int currentTrack = 0; currentTrack < midiTracks.Count; currentTrack++)
{
MidiTrack cTrk = midiTracks[currentTrack];
trackHeaderOffset[currentTrack] = midiWriter.BaseStream.Position; // save the offset to the track header
// write the header info
midiWriter.Write(Encoding.ASCII.GetBytes("MTrk"));
midiWriter.Write((int)0); // write 0 into the chunk length slot; it'll get filled later; 0 is the same in Little Endian as in Big, so we can use the normal int32 writing
trackStartOffset[currentTrack] = midiWriter.BaseStream.Position; // save the track beginning (doesn't point to the header, it points to the data)
long currentTick = 0; // init the current tick to 0 to calculate Delta Time values
for (int currentEvent = 0; currentEvent < cTrk.midiEvents.Count; currentEvent++)
{
// write the Delta time to the stream
midiWriter.Write(VariableLength.ConvertToVariableLength(cTrk.midiEvents[currentEvent].absoluteTicks - currentTick));
// write the actual Event data
midiWriter.Write(cTrk.midiEvents[currentEvent].getEventData());
currentTick = cTrk.midiEvents[currentEvent].absoluteTicks;
}
midiWriter.Write((byte)0x0); // write delta time for track end
midiWriter.Write((byte)0xFF); // write META event byte
midiWriter.Write((byte)0x2F); // write End of Track byte
midiWriter.Write((byte)0x0); // the length of this META event data is 0 (no data follows)
trackEndOffset[currentTrack] = midiWriter.BaseStream.Position; // calc the length of the event data and backup the position
} // end of track loop
midiWriter.BaseStream.Close();
// close the filestreams and create a new one to edit the file
midiFileStream = new FileStream(filePath, FileMode.Open, FileAccess.Write, FileShare.None);
midiWriter = new BinaryWriter(midiFileStream);
for (int currentTrack = 0; currentTrack < midiTracks.Count; currentTrack++)
{
midiWriter.BaseStream.Position = trackHeaderOffset[currentTrack] + 4;
midiWriter.Write(intToBigEndian((int)(trackEndOffset[currentTrack] - trackStartOffset[currentTrack])));
}
midiWriter.Close();
// close filestream and finish
Console.WriteLine("Successfully finished creating MIDI file!");
} // end of function
