Exemple #1
0
        static MidiTrack ReadTrack(MidiDataStreamReader reader)
        {
            var track = new MidiTrack();

            // Chunk type.
            if (new string (reader.ReadChars(4)) != "MTrk")
            {
                throw new System.FormatException("Can't find track chunk.");
            }

            // Chunk length.
            var chunkEnd = reader.ReadBEInt32();

            chunkEnd += reader.Offset;

            // Read delta-time and event pairs.
            byte ev = 0;

            while (reader.Offset < chunkEnd)
            {
                // Delta time.
                var delta = reader.ReadMultiByteValue();

                // Event type.
                if ((reader.PeekByte() & 0x80) != 0)
                {
                    ev = reader.ReadByte();
                }

                if (ev == 0xff)
                {
                    // 0xff: Meta event
                    byte   type   = reader.ReadByte();
                    byte   length = reader.ReadByte();
                    byte[] data   = reader.ReadBytes(length);
                    track.AddEvent(delta, new MetaEvent(type, data));
                }
                else if (ev == 0xf0)
                {
                    // 0xf0: SysEx (unused).
                    while (reader.ReadByte() != 0xf7)
                    {
                    }
                }
                else
                {
                    // MIDI event
                    byte data1 = reader.ReadByte();
                    byte data2 = ((ev & 0xe0) == 0xc0) ? (byte)0 : reader.ReadByte();
                    track.AddEvent(delta, new MidiEvent(ev, data1, data2));
                }
            }

            return(track);
        }
Exemple #2
0
        public static MidiFileContainer Load(byte[] data)
        {
            var tracks = new List <MidiTrack> ();
            var reader = new MidiDataStreamReader(data);

            // Chunk type.
            if (new string (reader.ReadChars(4)) != "MThd")
            {
                throw new System.FormatException("Can't find header chunk.");
            }

            // Chunk length.
            if (reader.ReadBEInt32() != 6)
            {
                throw new System.FormatException("Length of header chunk must be 6.");
            }

            // Format (unused).
            reader.Advance(2);

            // Number of tracks.
            var trackCount = reader.ReadBEInt16();

            // Delta-time divisions.
            var division = reader.ReadBEInt16();

            if ((division & 0x8000) != 0)
            {
                throw new System.FormatException("SMPTE time code is not supported.");
            }

            // Read the tracks.
            for (var trackIndex = 0; trackIndex < trackCount; trackIndex++)
            {
                tracks.Add(ReadTrack(reader));
            }

            return(new MidiFileContainer(division, tracks));
        }