Click here to Skip to main content
Click here to Skip to main content
 
Add your own
alternative version
Go to top

C# MIDI Toolkit

, 18 Apr 2007
A toolkit for creating MIDI applications with C#.
csharpmiditoolkitv4_demo.zip
CSharpMidiToolkitV4_demo
LSCollections.dll
MidiToolkitDemo
Properties
Settings.settings
MidiWatcher
Properties
Settings.settings
Multimedia.dll
Multimedia.Midi
Clocks
Device Classes
InputDevice Class
OutputDevice Classes
Messages
Message Builders
Multimedia.Midi.csproj.user
Processing
Sequencing
Midi File Player
Track Classes
UI
StateMachineToolkit.dll
csharpmiditoolkitv5_demo.zip
CSharpMidiToolkitV5_demo
MidiWatcher
Properties
Settings.settings
Sanford.Collections.dll
Sanford.Multimedia.dll
Sanford.Multimedia.Midi
Clocks
Device Classes
InputDevice Class
OutputDevice Classes
Messages
EventArgs
Message Builders
Processing
Sanford.Multimedia.Midi.csproj.user
Sequencing
Track Classes
UI
Sanford.Multimedia.Timers.dll
Sanford.Threading.dll
SequencerDemo
Properties
Settings.settings
miditoolkit_demo.zip
CSharpMidiToolkit
MidiToolkitDemo
App.ico
MidiToolkitDemo.csproj.user
Multimedia
Multimedia.csproj.user
Multimedia.Midi
Devices
Messages
Message Adaptors
MIDI File
Multimedia.MIDI.csproj.user
Sequencing
Synchronization
UI
miditoolkit_src.zip
MidiToolkit_src
Devices
Messages
MIDI File
Sequencing
TickGenerators
UI
#region License

/* Copyright (c) 2005 Leslie Sanford
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to 
 * deal in the Software without restriction, including without limitation the 
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
 * sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE.
 */

#endregion

#region Contact

/*
 * Leslie Sanford
 * Email: jabberdabber@hotmail.com
 */

#endregion

using System;
using System.ComponentModel;
using System.Diagnostics;

namespace Multimedia.Midi
{
    #region Meta Message Types

    /// <summary>
    /// Represents MetaMessage types.
    /// </summary>
    public enum MetaType
    {
        /// <summary>
        /// Represents sequencer number type.
        /// </summary>
        SequenceNumber,

        /// <summary>
        /// Represents the text type.
        /// </summary>
        Text,

        /// <summary>
        /// Represents the copyright type.
        /// </summary>
        Copyright,

        /// <summary>
        /// Represents the track name type.
        /// </summary>
        TrackName,

        /// <summary>
        /// Represents the instrument name type.
        /// </summary>
        InstrumentName,

        /// <summary>
        /// Represents the lyric type.
        /// </summary>
        Lyric,

        /// <summary>
        /// Represents the marker type.
        /// </summary>
        Marker,

        /// <summary>
        /// Represents the cue point type.
        /// </summary>
        CuePoint,

        /// <summary>
        /// Represents the program name type.
        /// </summary>
        ProgramName,

        /// <summary>
        /// Represents the device name type.
        /// </summary>
        DeviceName,

        /// <summary>
        /// Represents then end of track type.
        /// </summary>
        EndOfTrack = 0x2F,

        /// <summary>
        /// Represents the tempo type.
        /// </summary>
        Tempo = 0x51,

        /// <summary>
        /// Represents the Smpte offset type.
        /// </summary>
        SmpteOffset = 0x54,

        /// <summary>
        /// Represents the time signature type.
        /// </summary>
        TimeSignature = 0x58,

        /// <summary>
        /// Represents the key signature type.
        /// </summary>
        KeySignature,

        /// <summary>
        /// Represents the proprietary event type.
        /// </summary>
        ProprietaryEvent = 0x7F
    }

    #endregion

	/// <summary>
	/// Represents MIDI meta messages.
	/// </summary>
	/// <remarks>
	/// Meta messages are MIDI messages that are stored in MIDI files. These
	/// messages are not sent or received via MIDI but are read and 
	/// interpretted from MIDI files. They provide information that describes 
	/// a MIDI file's properties. For example, tempo changes are implemented
	/// using meta messages.
	/// </remarks>
	[ImmutableObject(true)]
	public sealed class MetaMessage : IMidiMessage
	{
        #region MetaMessage Members

        #region Constants

        /// <summary>
        /// The amount to shift data bytes when calculating the hash code.
        /// </summary>
        private const int Shift = 7;

        //
        // Meta message length constants.
        //

        /// <summary>
        /// Length in bytes for tempo meta message data.
        /// </summary>
        public const int TempoLength = 3;

        /// <summary>
        /// Length in bytes for SMPTE offset meta message data.
        /// </summary>
        public const int SmpteOffsetLength = 5;

        /// <summary>
        /// Length in bytes for time signature meta message data.
        /// </summary>
        public const int TimeSigLength = 4;

        /// <summary>
        /// Length in bytes for key signature meta message data.
        /// </summary>
        public const int KeySigLength = 2;

        #endregion

        #region Class Fields

        /// <summary>
        /// End of track meta message.
        /// </summary>
        public static readonly MetaMessage EndOfTrackMessage = 
            new MetaMessage(MetaType.EndOfTrack, new byte[0]);

        #endregion

        #region Fields

        // The meta message type.
        private MetaType type;

        // The meta message data.
        private byte[] data;

        // The hash code value.
        private int hashCode;

        #endregion

        #region Construction

        /// <summary>
        /// Initializes a new instance of the MetaMessage class.
        /// </summary>
        /// <param name="type">
        /// The type of MetaMessage.
        /// </param>
        /// <param name="data">
        /// The MetaMessage data.
        /// </param>
        /// <exception cref="ArgumentException">
        /// The length of the MetaMessage is not valid for the MetaMessage type.
        /// </exception>
        /// <remarks>
        /// Each MetaMessage has type and length properties. For certain 
        /// types, the length of the message data must be a specific value. For
        /// example, tempo messages must have a data length of exactly three. 
        /// Some MetaMessage types can have any data length. Text messages are
        /// an example of a MetaMessage that can have a variable data length.
        /// When a MetaMessage is created, the length of the data is checked
        /// to make sure that it is valid for the specified type. If it is not,
        /// an exception is thrown. 
        /// </remarks>
		public MetaMessage(MetaType type, byte[] data)
        {
            #region Require

            if(data == null)
            {
                throw new ArgumentNullException("data");
            }
            else if(!ValidateDataLength(type, data.Length))
            {
                throw new ArgumentException(
                    "Length of data not valid for meta message type.");
            }

            #endregion

            this.type = type;
            
            // Create storage for meta message data.
            this.data = new byte[data.Length];

            // Copy data into storage.
            data.CopyTo(this.data, 0);

            CalculateHashCode();
        }

        #endregion

        #region Methods
        
        /// <summary>
        /// Gets a copy of the data bytes for this meta message.
        /// </summary>
        /// <returns>
        /// A copy of the data bytes for this meta message.
        /// </returns>
        public byte[] GetBytes()
        {
            return (byte[])data.Clone();
        }

        /// <summary>
        /// Returns a value for the current MetaMessage suitable for use in 
        /// hashing algorithms.
        /// </summary>
        /// <returns>
        /// A hash code for the current MetaMessage.
        /// </returns>
        public override int GetHashCode()
        {
            return hashCode;            
        }

        /// <summary>
        /// Determines whether two MetaMessage instances are equal.
        /// </summary>
        /// <param name="obj">
        /// The MetaMessage to compare with the current MetaMessage.
        /// </param>
        /// <returns>
        /// <b>true</b> if the specified MetaMessage is equal to the current 
        /// MetaMessage; otherwise, <b>false</b>.
        /// </returns>
        public override bool Equals(object obj)
        {
            #region Guard

            if(!(obj is MetaMessage))
            {
                return false;
            }

            #endregion

            bool equal = true;
            MetaMessage message = (MetaMessage)obj;

            // If the types do not match.
            if(MetaType != message.MetaType)
            {
                // The messages are not equal
                equal = false;
            }

            // If the message lengths are not equal.
            if(equal && Length != message.Length)
            {
                // The message are not equal.
                equal = false;
            }

            // Check to see if the data is equal.
            for(int i = 0; i < Length && equal; i++)
            {
                // If a data value does not match.
                if(this[i] != message[i])
                {
                    // The messages are not equal.
                    equal = false;
                }
            }

            return equal;
        }

        // Calculates the hash code.
        private void CalculateHashCode()
        {            
            // TODO: This algorithm may need work.

            hashCode = (int)MetaType;

            for(int i = 0; i < data.Length; i += 3)
            {
                hashCode ^= data[i];
            }

            for(int i = 1; i < data.Length; i += 3)
            {
                hashCode ^= data[i] << Shift;
            }

            for(int i = 2; i < data.Length; i += 3)
            {
                hashCode ^= data[i] << Shift * 2;
            }
        }

        /// <summary>
        /// Validates data length.
        /// </summary>
        /// <param name="type">
        /// The MetaMessage type.
        /// </param>
        /// <param name="length">
        /// The length of the MetaMessage data.
        /// </param>
        /// <returns>
        /// <b>true</b> if the data length is valid for this type of 
        /// MetaMessage; otherwise, <b>false</b>.
        /// </returns>
        private bool ValidateDataLength(MetaType type, int length)
        {
            #region Require

            Debug.Assert(length >= 0);

            #endregion

            bool result = true;

            // Determine which type of meta message this is and check to make
            // sure that the data length value is valid.
            switch(type)
            {
                case MetaType.SequenceNumber:
                    if(length != 0 || length != 2)
                    {
                        result = false;
                    }
                    break;

                case MetaType.EndOfTrack:
                    if(length != 0)
                    {
                        result = false;
                    }
                    break;

                case MetaType.Tempo:
                    if(length != TempoLength)
                    {
                        result = false;
                    }
                    break;

                case MetaType.SmpteOffset:
                    if(length != SmpteOffsetLength)
                    {
                        result = false;
                    }
                    break;

                case MetaType.TimeSignature:
                    if(length != TimeSigLength)
                    {
                        result = false;
                    }
                    break;

                case MetaType.KeySignature:
                    if(length != KeySigLength)
                    {
                        result = false;
                    }
                    break;

                default:
                    result = true;
                    break;
            }

            return result;      
        }

        #endregion

        #region Properties

        /// <summary>
        /// Gets the element at the specified index.
        /// </summary>
        /// <exception cref="ArgumentOutOfRangeException">
        /// index is less than zero or greater than or equal to Length.
        /// </exception>
        public byte this[int index]
        {
            get
            {
                #region Require

                if(index < 0 || index >= Length)
                {
                    throw new ArgumentOutOfRangeException("index", index,
                        "Index into MetaMessage out of range.");
                }

                #endregion

                return data[index];
            }
        }

        /// <summary>
        /// Gets the length of the meta message.
        /// </summary>
        public int Length
        {
            get
            { 
                return data.Length;
            }
        }
        
        /// <summary>
        /// Gets the type of meta message.
        /// </summary>
        public MetaType MetaType
        {
            get
            {
                return type;
            }
        }

        #endregion

        #endregion        

        #region IMidiMessage Members

        /// <summary>
        /// Gets the status value.
        /// </summary>
        public int Status
        {
            get
            {
                // All meta messages have the same status value (0xFF).
                return 0xFF;
            }
        }

        /// <summary>
        /// Gets the MetaMessage's MessageType.
        /// </summary>
        public MessageType MessageType
        {
            get
            {
                return MessageType.Meta;
            }
        }

        #endregion
    }
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The MIT License

Share

About the Author

Leslie Sanford

United States United States
Aside from dabbling in BASIC on his old Atari 1040ST years ago, Leslie's programming experience didn't really begin until he discovered the Internet in the late 90s. There he found a treasure trove of information about two of his favorite interests: MIDI and sound synthesis.
 
After spending a good deal of time calculating formulas he found on the Internet for creating new sounds by hand, he decided that an easier way would be to program the computer to do the work for him. This led him to learn C. He discovered that beyond using programming as a tool for synthesizing sound, he loved programming in and of itself.
 
Eventually he taught himself C++ and C#, and along the way he immersed himself in the ideas of object oriented programming. Like many of us, he gotten bitten by the design patterns bug and a copy of GOF is never far from his hands.
 
Now his primary interest is in creating a complete MIDI toolkit using the C# language. He hopes to create something that will become an indispensable tool for those wanting to write MIDI applications for the .NET framework.
 
Besides programming, his other interests are photography and playing his Les Paul guitars.

| Advertise | Privacy | Mobile
Web03 | 2.8.140916.1 | Last Updated 18 Apr 2007
Article Copyright 2004 by Leslie Sanford
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid