Best way to play MIDI sounds using C#

Question

I\'m trying to rebuild an old metronome application that was originally written using MFC in C++ to be written in .NET using C#. One o

Answer 1

A recent addition is MIDI.NET that supports Midi Ports, Midi Files and SysEx.

Answer 2

I think you'll need to p/invoke out to the windows api to be able to play midi files from .net.

This codeproject article does a good job on explaining how to do this: vb.net article to play midi files

To rewrite this is c# you'd need the following import statement for mciSendString:

[DllImport("winmm.dll")] 
static extern Int32 mciSendString(String command, StringBuilder buffer, 
                                  Int32 bufferSize, IntPtr hwndCallback);

Hope this helps - good luck!

Answer 3

Sorry this question is a little old now, but the following worked for me (somewhat copied from Win32 - Midi looping with MCISendString):

[DllImport("winmm.dll")]
static extern Int32 mciSendString(String command, StringBuilder buffer, Int32 bufferSize, IntPtr hwndCallback);

public static void playMidi(String fileName, String alias)
{
  mciSendString("open " + fileName + " type sequencer alias " + alias, new StringBuilder(), 0, new IntPtr());
  mciSendString("play " + alias, new StringBuilder(), 0, new IntPtr());
}

public static void stopMidi(String alias)
{
  mciSendString("stop " + alias, null, 0, new IntPtr());
  mciSendString("close " + alias, null, 0, new IntPtr());
}

A full listing of command strings is given here. The cool part about this is you can just use different things besides sequencer to play different things, say waveaudio for playing .wav files. I can't figure out how to get it to play .mp3 though.

Also, note that the stop and close command must be sent on the same thread that the open and play commands were sent on, otherwise they will have no effect and the file will remain open. For example:

[DllImport("winmm.dll")]
static extern Int32 mciSendString(String command, StringBuilder buffer,
                                    Int32 bufferSize, IntPtr hwndCallback);

public static Dictionary<String, bool> playingMidi = new Dictionary<String, bool>();

public static void PlayMidi(String fileName, String alias)
{
    if (playingMidi.ContainsKey(alias))
        throw new Exception("Midi with alias '" + alias + "' is already playing");

    playingMidi.Add(alias, false);

    Thread stoppingThread = new Thread(() => { StartAndStopMidiWithDelay(fileName, alias); });
    stoppingThread.Start();
}

public static void StopMidiFromOtherThread(String alias)
{
    if (!playingMidi.ContainsKey(alias))
        return;

    playingMidi[alias] = true;
}

public static bool isPlaying(String alias)
{
    return playingMidi.ContainsKey(alias);
}

private static void StartAndStopMidiWithDelay(String fileName, String alias)
{
    mciSendString("open " + fileName + " type sequencer alias " + alias, null, 0, new IntPtr());
    mciSendString("play " + alias, null, 0, new IntPtr());

    StringBuilder result = new StringBuilder(100);
    mciSendString("set " + alias + " time format milliseconds", null, 0, new IntPtr());
    mciSendString("status " + alias + " length", result, 100, new IntPtr());

    int midiLengthInMilliseconds;
    Int32.TryParse(result.ToString(), out midiLengthInMilliseconds);

    Stopwatch timer = new Stopwatch();
    timer.Start();

    while(timer.ElapsedMilliseconds < midiLengthInMilliseconds && !playingMidi[alias])
    {

    }

    timer.Stop();

    StopMidi(alias);
}

private static void StopMidi(String alias)
{
    if (!playingMidi.ContainsKey(alias))
        throw new Exception("Midi with alias '" + alias + "' is already stopped");

    // Execute calls to close and stop the player, on the same thread as the play and open calls
    mciSendString("stop " + alias, null, 0, new IntPtr());
    mciSendString("close " + alias, null, 0, new IntPtr());

    playingMidi.Remove(alias);
}

Answer 4

For extensive MIDI and Wave manipulation in .NET, I think hands down NAudio is the solution (Also available via NuGet).

Answer 5

I think it's much better to use some library that which has advanced features for MIDI data playback instead of implementing it by your own. For example, with DryWetMIDI (I'm the author of it) to play MIDI file via default synthesizer (Microsoft GS Wavetable Synth):

using Melanchall.DryWetMidi.Devices;
using Melanchall.DryWetMidi.Core;

// ...

var midiFile = MidiFile.Read("Greatest song ever.mid");

using (var outputDevice = OutputDevice.GetByName("Microsoft GS Wavetable Synth"))
{
    midiFile.Play(outputDevice);
}

Play will block the calling thread until entire file played. To control playback of a MIDI file, obtain Playback object and use its Start/Stop methods (more details in the Playback article of the library docs):

var playback = midiFile.GetPlayback(outputDevice);

// You can even loop playback and speed it up
playback.Loop = true;
playback.Speed = 2.0;

playback.Start();

// ...

playback.Stop();

// ...

playback.Dispose();
outputDevice.Dispose();