Streaming input to System.Speech.Recognition.SpeechRecognitionEngine

Question

I am trying to do \"streaming\" speech recognition in C# from a TCP socket. The problem I am having is that SpeechRecognitionEngine.SetInputToAudioStream() seems to require

Answer 1

This is my solution.

class FakeStreamer : Stream
{
    public bool bExit = false;
    Stream stream;
    TcpClient client;
    public FakeStreamer(TcpClient client)
    {
        this.client = client;
        this.stream = client.GetStream();
        this.stream.ReadTimeout = 100; //100ms
    }
    public override bool CanRead
    {
        get { return stream.CanRead; }
    }

    public override bool CanSeek
    {
        get { return false; }
    }

    public override bool CanWrite
    {
        get { return stream.CanWrite; }
    }

    public override long Length
    {
        get { return -1L; }
    }

    public override long Position
    {
        get { return 0L; }
        set { }
    }
    public override long Seek(long offset, SeekOrigin origin)
    {
        return 0L;
    }

    public override void SetLength(long value)
    {
        stream.SetLength(value);
    }
    public override int Read(byte[] buffer, int offset, int count)
    {
        int len = 0, c = count;
        while (c > 0 && !bExit)
        {
            try
            {
                len = stream.Read(buffer, offset, c);
            }
            catch (Exception e)
            {
                if (e.HResult == -2146232800) // Timeout
                {
                    continue;
                }
                else
                {
                    //Exit read loop
                    break;
                }
            }
            if (!client.Connected || len == 0)
            {
                //Exit read loop
                return 0;
            }
            offset += len;
            c -= len;
        }
        return count;
    }

    public override void Write(byte[] buffer, int offset, int count)
    {
        stream.Write(buffer,offset,count);
    }

    public override void Close()
    {
        stream.Close();
        base.Close();
    }

    public override void Flush()
    {
        stream.Flush();
    }
}

How to Use:

//client connect in
TcpClient clientSocket = ServerSocket.AcceptTcpClient();
FakeStreamer buffStream = new FakeStreamer(clientSocket);
...
//recognizer init
m_recognizer.SetInputToAudioStream(buffStream , audioFormat);
...
//recognizer end
if (buffStream != null)
    buffStream.bExit = true;