public class DTMFGenerator : IDisposable

Public Class DTMFGenerator
	Implements IDisposable

public ref class DTMFGenerator : IDisposable

type DTMFGenerator =  
    class
        interface IDisposable
    end

class Modulator
{
    public Modulator()
    {
        offset = 0;
        q = new Queue<byte[]>();
    }

    ~Modulator()
    {
        q.Clear();
    }

    public void Add(byte[] buffer)
    {
        lock (q) { q.Enqueue(buffer); }
    }

    public byte[] Modulate(byte[] buffer)
    {
        if (q.Count == 0)
            return buffer;
        int bufferOff = 0;
        byte[] modBuf = Peek();
        while (bufferOff < buffer.Length)
        {
            buffer[bufferOff++] += modBuf[offset++];
            if (offset >= modBuf.Length)
            {
                lock (q) { q.Dequeue(); }
                offset = 0;
                if (q.Count == 0)
                    break;
                modBuf = Peek();
            }
        }
        return buffer;
    }
    private byte[] Peek()
    {
        lock (q) { return q.Peek(); }
    }
    private int offset;
    Queue<byte[]> q;
}

class Program
{
    static void Main(string[] args)
    {
        Modulator mod = new Modulator();

        WaveOutput wout = new WaveOutput();
        wout.BitsPerSample = 16;
        wout.Channels = 1;
        wout.SampleRate = 8000;
        wout.Init();
        wout.OpenDevice();

        WaveInput win = new WaveInput();
        win.BitsPerSample = 16;
        win.Channels = 1;
        win.SampleRate = 8000;
        win.TransferBufferCount = 200;
        win.TransferBufferSize = 8000 * 2 / 50;
        win.Init();
        win.OpenDevice();
        win.Start();

        DTMFGenerator tg = new DTMFGenerator();
        tg.SampleFrequency = 8000;

        bool res = tg.Init();

        uint duration = 200;

        Console.WriteLine("Enter 0-9, #, * ");
        win.ClearBuffers();
        while (true)
        {
            if (win.SamplesAvailable)
            {
                byte[] inBuf = win.GetAllData();
                if (inBuf != null)
                {
                    inBuf = mod.Modulate(inBuf);
                    wout.Enqueue(inBuf);
                }

            }
            if (Console.KeyAvailable == false)
            {
                System.Threading.Thread.Sleep(10);
                continue;
            }

            var ki = Console.ReadKey(false);
            if (ki.Key == ConsoleKey.X || ki.Key == ConsoleKey.Escape)
                break;
            byte[] buf = tg.Generate((sbyte)char.ToUpper(ki.KeyChar), duration, 6);

            if (buf != null)
            {
                Console.WriteLine("Generated {0} for {1} ({2} bytes)", ki.Key.ToString(), duration, buf.Length);
                mod.Add(buf);
            }
            else
                Console.WriteLine("not a dtmf tone");

        }
    }
}