private static void WriteMidiTrack(MidiFileFormatWriter mffw, MidiTrack track)
{
// Write out track marker
mffw.WriteString(MidiFileFormat.midiTrackMarker, false);
// Run 2 passes, one to compute the length to be written, and one to actually write out the data
mffw.CountingMode = true;
mffw.ResetBytesWritten();
for (int pass = 0; pass < 2; pass++)
{
byte runningStatus = 0;
// Write out all events
for (LinkedListNode <MidiEvent> n = track.EventList.First; n != null; n = n.Next)
{
runningStatus = WriteMidiEvent(mffw, n.Value, runningStatus);
}
// At the end of the first pass, write out the count
if (pass == 0)
{
mffw.CountingMode = false;
uint count = mffw.BytesWritten;
mffw.WriteUInt32(count);
}
}
}
private static byte WriteMidiEvent(MidiFileFormatWriter mffw, MidiEvent evt, byte runningStatus)
{
// Write out delta time
mffw.WriteVarLengthQuantity(evt.TrackDeltaTime);
// Write out the message
return(WriteMidiMessage(mffw, evt.Message, runningStatus));
}
public static void WriteMidiFile(MidiSequence sequence, string filename)
{
MidiFileFormatWriter mffw = new MidiFileFormatWriter(filename);
using (mffw)
{
// Write magic number
mffw.WriteString(MidiFileFormat.midiFileMarker, false);
// Write header size
mffw.WriteUInt32(MidiFileFormat.midiFileHeaderLength);
// Write header
mffw.WriteUInt16(MidiFileFormat.midiFileVersion);
mffw.WriteUInt16((ushort)sequence.Tracks.Count);
mffw.WriteUInt16((ushort)((sequence.PPQN > 0) ? sequence.PPQN : (sequence.SMPTETempo | 0x8000)));
// Write out the tracks
for (int t = 0; t < sequence.Tracks.Count; t++)
{
WriteMidiTrack(mffw, sequence.Tracks[t]);
}
}
}
// Write a midi message to a midi file
private static byte WriteMidiMessage(MidiFileFormatWriter mffw, MidiMessage message, byte runningStatus)
{
// Write out the command unless it is the same as the running status
byte firstByte = message.GetFirstByte();
if (firstByte != runningStatus)
{
mffw.WriteUInt8(firstByte);
runningStatus = firstByte;
}
// Act according to message type
if (message is MidiSysexMessage)
{
runningStatus = 0;
byte[] body = ((MidiSysexMessage)message).Body;
// Write out length (-1 to skip F0)
mffw.WriteVarLengthQuantity((uint)body.Length - 1);
// Write out body
for (int b = 1; b < (body.Length - 1); b++)
{
if ((body[b] & 0x80) != 0)
{
throw new ArgumentException("WriteMidiMessage: Write Sysex: high bit set in body");
}
mffw.WriteUInt8(body[b]);
}
// Write out end of sysex
mffw.WriteUInt8((byte)EMidiCommand.EndOfSystemExclusive);
}
else if (message is MidiMetaMessage)
{
runningStatus = 0;
WriteMidiMetaMessage(mffw, message as MidiMetaMessage);
}
else if (message is MidiNoteMessage)
{
var note = message as MidiNoteMessage;
mffw.WriteUInt8((byte)note.Note);
mffw.WriteUInt8((byte)note.Velocity);
}
else if (message is MidiControlChangeMessage)
{
var cc = message as MidiControlChangeMessage;
mffw.WriteUInt8((byte)cc.Controller);
mffw.WriteUInt8((byte)cc.Value);
}
else if (message is MidiPatchChangeMessage)
{
var pc = message as MidiPatchChangeMessage;
mffw.WriteUInt8((byte)pc.Patch);
}
else if (message is MidiChannelAfterTouchMessage)
{
var cat = message as MidiChannelAfterTouchMessage;
mffw.WriteUInt8((byte)cat.Velocity);
}
else if (message is MidiPitchChangeMessage)
{
var pc = message as MidiPitchChangeMessage;
uint pitch = (uint)(pc.Pitch + 0x2000);
mffw.WriteUInt8((byte)(pitch & 0x7f));
mffw.WriteUInt8((byte)((pitch >> 7) & 0x7f));
}
else
{
throw new FormatException(string.Format("Found event type {0} - not supported!", message.GetType().FullName));
}
return(runningStatus);
}
static private void WriteMidiMetaMessage(MidiFileFormatWriter mffw, MidiMetaMessage message)
{
// Write out message type
mffw.WriteUInt8((byte)message.Type);
// Write out message content
if (message is MidiMetaTrackSequenceNumberMessage)
{
var m = message as MidiMetaTrackSequenceNumberMessage;
mffw.WriteVarLengthQuantity(2);
mffw.WriteUInt16((ushort)m.SequenceNumber);
}
else if (message is MidiMetaTextMessage)
{
var m = message as MidiMetaTextMessage;
mffw.WriteString(m.Text, true);
}
else if (message is MidiMetaMidiPortMessage)
{
var m = message as MidiMetaMidiPortMessage;
mffw.WriteVarLengthQuantity(1);
mffw.WriteUInt8((byte)m.Port);
}
else if (message is MidiMetaTempoMessage)
{
var m = message as MidiMetaTempoMessage;
mffw.WriteVarLengthQuantity(3);
mffw.WriteUInt24(m.Tempo);
}
else if (message is MidiMetaTimeSignatureMessage)
{
var m = message as MidiMetaTimeSignatureMessage;
mffw.WriteVarLengthQuantity(4);
mffw.WriteUInt8((byte)m.Numerator);
mffw.WriteUInt8((byte)m.Denominator);
mffw.WriteUInt8((byte)m.TicksInMetronomeClick);
mffw.WriteUInt8((byte)m.No32ndNotesInQuarterNote);
}
else if (message is MidiMetaKeySignatureMessage)
{
var m = message as MidiMetaKeySignatureMessage;
mffw.WriteVarLengthQuantity(2);
mffw.WriteUInt8((byte)((m.Sharps > 0) ? m.Sharps : -m.Flats));
mffw.WriteUInt8((byte)(m.Minor ? 1 : 0));
}
else if (message.Type == EMetaEventType.SequencerSpecific)
{
mffw.WriteVarLengthQuantity((uint)message.Body.Length);
for (int b = 0; b < message.Body.Length; b++)
{
mffw.WriteUInt8(message.Body[b]);
}
}
else if (message.Type == EMetaEventType.EndTrack)
{
mffw.WriteVarLengthQuantity(0);
}
else
{
throw new FormatException(string.Format("Found event type {0} - not supported!", message.GetType().FullName));
}
}
