private static void UpdateTrackEnd(ICollection <MidiEvent> events, long?newTime = null)
{
var endTrack = events.SingleOrDefault(MidiEvent.IsEndTrack);
long absoluteTime;
if (newTime == null)
{
var lastEvent = events.Where(e => !MidiEvent.IsEndTrack(e)).OrderBy(e => e.AbsoluteTime).LastOrDefault();
absoluteTime = lastEvent?.AbsoluteTime ?? 0;
}
else
{
absoluteTime = newTime.Value;
}
if (endTrack == null)
{
events.Add(new MetaEvent(MetaEventType.EndTrack, 0, absoluteTime));
}
else
{
events.Remove(endTrack);
endTrack.AbsoluteTime = absoluteTime;
events.Add(endTrack);
}
}
private bool RemoveTrackIfEmpty(MidiEventCollection midi, int trackNumber)
{
// If a track only has an EndTrack (and optionally a name) then it is "empty"
if (midi[trackNumber].All(e => e.IsSequenceTrackName() || MidiEvent.IsEndTrack(e)))
{
midi.RemoveTrack(trackNumber);
return(true);
}
return(false);
}
public static MemoryStream ExportMidiToStream(MidiEventCollection events)
{
//Taken from https://github.com/naudio/NAudio/blob/master/NAudio/Midi/MidiFile.cs#L256 and edited to support MemoryStream export(thanks Mettra)
if (events.MidiFileType == 0 && events.Tracks > 1)
{
throw new ArgumentException("Can't export more than one track to a type 0 file");
}
using (MemoryStream stream = new MemoryStream())
{
using (var writer = new BinaryWriter(stream))
{
writer.Write(Encoding.UTF8.GetBytes("MThd"));
writer.Write(SwapUInt32(6)); // chunk size
writer.Write(SwapUInt16((ushort)events.MidiFileType));
writer.Write(SwapUInt16((ushort)events.Tracks));
writer.Write(SwapUInt16((ushort)events.DeltaTicksPerQuarterNote));
for (int track = 0; track < events.Tracks; track++)
{
IList <MidiEvent> eventList = events[track];
writer.Write(Encoding.UTF8.GetBytes("MTrk"));
long trackSizePosition = writer.BaseStream.Position;
writer.Write(SwapUInt32(0));
long absoluteTime = events.StartAbsoluteTime;
// use a stable sort to preserve ordering of MIDI events whose
// absolute times are the same
MergeSort.Sort(eventList, new MidiEventComparer());
if (eventList.Count > 0)
{
System.Diagnostics.Debug.Assert(MidiEvent.IsEndTrack(eventList[eventList.Count - 1]), "Exporting a track with a missing end track");
}
foreach (var midiEvent in eventList)
{
midiEvent.Export(ref absoluteTime, writer);
}
uint trackChunkLength = (uint)(writer.BaseStream.Position - trackSizePosition) - 4;
writer.BaseStream.Position = trackSizePosition;
writer.Write(SwapUInt32(trackChunkLength));
writer.BaseStream.Position += trackChunkLength;
}
}
stream.Flush();
byte[] bytes = stream.GetBuffer();
return(new MemoryStream(bytes));
}
}
public void ConsolidateTracks(MidiEventCollection midi)
{
// find all of the names
var nameCounts = new Dictionary <string, int>();
for (var t = 0; t < midi.Tracks; t++)
{
var names = midi[t].
OfType <TextEvent>().
Where(e => e.MetaEventType == MetaEventType.SequenceTrackName).
ToList();
if (names.Count > 1)
{
var detail = string.Join(", ", names.Select(n => $"'{n.Text}'"));
throw new InvalidOperationException($"Multiple names {detail} on the same track.");
}
var name = names.FirstOrDefault()?.Text ?? "";
int count;
nameCounts.TryGetValue(name, out count);
nameCounts[name] = count + 1;
}
/* For all of the names that appear on more than one track
* find all the other tracks that have this name and consolidate them.
* We iterate multiple times because the track numbers will change every
* time tracks are consolidated. */
foreach (var kvp in nameCounts.Where(kvp => kvp.Value > 1))
{
var name = kvp.Key;
var list = new List <MidiEvent>();
// iterate in reverse so track numbers don't change mid iteration
for (var t = midi.Tracks - 1; t >= 0; t--)
{
if (!midi[t].OfType <TextEvent>().Any(e => e.IsSequenceTrackName() && e.Text == name))
{
continue;
}
var events = midi[t].Where(e => !MidiEvent.IsEndTrack(e) && !e.IsSequenceTrackName());
list.AddRange(events);
midi.RemoveTrack(t);
}
midi.AddNamedTrack(name, list.OrderBy(e => e.AbsoluteTime));
}
}
/// <summary>
/// Exports a MIDI file
/// </summary>
/// <param name="filename">Filename to export to</param>
/// <param name="events">Events to export</param>
public static void Export(string filename, MidiEventCollection events)
{
if (events.MidiFileType == 0 && events.Tracks > 1)
{
throw new ArgumentException("Can't export more than one track to a type 0 file");
}
using (var writer = new BinaryWriter(File.Create(filename)))
{
writer.Write(Encoding.UTF8.GetBytes("MThd"));
writer.Write(SwapUInt32((uint)6)); // chunk size
writer.Write(SwapUInt16((ushort)events.MidiFileType));
writer.Write(SwapUInt16((ushort)events.Tracks));
writer.Write(SwapUInt16((ushort)events.DeltaTicksPerQuarterNote));
for (int track = 0; track < events.Tracks; track++)
{
IList <MidiEvent> eventList = events[track];
writer.Write(Encoding.UTF8.GetBytes("MTrk"));
long trackSizePosition = writer.BaseStream.Position;
writer.Write(SwapUInt32((uint)0));
long absoluteTime = events.StartAbsoluteTime;
// use a stable sort to preserve ordering of MIDI events whose
// absolute times are the same
MergeSort.Sort(eventList, new MidiEventComparer());
if (eventList.Count > 0)
{
System.Diagnostics.Debug.Assert(MidiEvent.IsEndTrack(eventList[eventList.Count - 1]), "Exporting a track with a missing end track");
}
foreach (MidiEvent midiEvent in eventList)
{
midiEvent.Export(ref absoluteTime, writer);
}
uint trackChunkLength = (uint)(writer.BaseStream.Position - trackSizePosition) - 4;
writer.BaseStream.Position = trackSizePosition;
writer.Write(SwapUInt32(trackChunkLength));
writer.BaseStream.Position += trackChunkLength;
}
}
}
public void TestType0()
{
MidiEventCollection collection = new MidiEventCollection(0, 120);
collection.AddEvent(new TextEvent("Test", MetaEventType.TextEvent, 0), 0);
collection.AddEvent(new NoteOnEvent(0, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(15, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(30, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(0, 10, 60, 100, 15), 10);
collection.AddEvent(new NoteOnEvent(15, 10, 60, 100, 15), 10);
collection.AddEvent(new NoteOnEvent(30, 10, 60, 100, 15), 10);
Assert.AreEqual(collection.Tracks, 1);
collection.PrepareForExport();
Assert.AreEqual(collection.Tracks, 1);
IList <MidiEvent> track0 = collection.GetTrackEvents(0);
Assert.AreEqual(track0.Count, 8);
Assert.IsTrue(MidiEvent.IsEndTrack(track0[track0.Count - 1]));
}
public void TestType0ToType1()
{
MidiEventCollection collection = new MidiEventCollection(0, 120);
collection.AddEvent(new TextEvent("Test", MetaEventType.TextEvent, 0), 0);
collection.AddEvent(new NoteOnEvent(0, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(15, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(30, 1, 30, 100, 15), 1);
collection.AddEvent(new NoteOnEvent(0, 10, 60, 100, 15), 10);
collection.AddEvent(new NoteOnEvent(15, 10, 60, 100, 15), 10);
collection.AddEvent(new NoteOnEvent(30, 10, 60, 100, 15), 10);
Assert.AreEqual(collection.Tracks, 1);
collection.MidiFileType = 1;
collection.PrepareForExport();
Assert.AreEqual(3, collection.Tracks, "Wrong number of tracks");
IList <MidiEvent> track0 = collection.GetTrackEvents(0);
Assert.AreEqual(track0.Count, 2);
Assert.AreEqual(collection.GetTrackEvents(1).Count, 4);
Assert.AreEqual(collection.GetTrackEvents(2).Count, 4);
Assert.IsTrue(MidiEvent.IsEndTrack(track0[track0.Count - 1]));
}
private static void ExportBinary(BinaryWriter writer, MidiEventCollection events)
{
writer.Write(System.Text.Encoding.UTF8.GetBytes("MThd"));
writer.Write(SwapUInt32(6)); // chunk size
writer.Write(SwapUInt16((ushort)events.MidiFileType));
writer.Write(SwapUInt16((ushort)events.Tracks));
writer.Write(SwapUInt16((ushort)events.DeltaTicksPerQuarterNote));
for (int track = 0; track < events.Tracks; track++)
{
IList <MidiEvent> eventList = events[track];
writer.Write(System.Text.Encoding.UTF8.GetBytes("MTrk"));
long trackSizePosition = writer.BaseStream.Position;
writer.Write(SwapUInt32(0));
long absoluteTime = events.StartAbsoluteTime;
// use a stable sort to preserve ordering of MIDI events whose
// absolute times are the same
MergeSort.Sort(eventList, new MidiEventComparer());
if (eventList.Count > 0 && !MidiEvent.IsEndTrack(eventList[eventList.Count - 1]))
{
Memory.Log.WriteLine("Exporting a track with a missing end track");
}
foreach (var midiEvent in eventList)
{
midiEvent.Export(ref absoluteTime, writer);
}
uint trackChunkLength = (uint)(writer.BaseStream.Position - trackSizePosition) - 4;
writer.BaseStream.Position = trackSizePosition;
writer.Write(SwapUInt32(trackChunkLength));
writer.BaseStream.Position += trackChunkLength;
}
}
