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SpeechRecognitionEngine.SetInputToAudioStream Method

  • Reference

Definition

Namespace:
System.Speech.Recognition
Assembly:
System.Speech.dll
Package:
System.Speech v8.0.0
Package:
System.Speech v9.0.0-rc.2.24473.5
Source:
SpeechRecognitionEngine.cs
Source:
SpeechRecognitionEngine.cs

Configures the SpeechRecognitionEngine object to receive input from an audio stream.

public:
 void SetInputToAudioStream(System::IO::Stream ^ audioSource, System::Speech::AudioFormat::SpeechAudioFormatInfo ^ audioFormat);
public void SetInputToAudioStream (System.IO.Stream audioSource, System.Speech.AudioFormat.SpeechAudioFormatInfo audioFormat);
member this.SetInputToAudioStream : System.IO.Stream * System.Speech.AudioFormat.SpeechAudioFormatInfo -> unit
Public Sub SetInputToAudioStream (audioSource As Stream, audioFormat As SpeechAudioFormatInfo)

Parameters

audioSource
Stream

The audio input stream.

audioFormat
SpeechAudioFormatInfo

The format of the audio input.

Examples

The following example shows part of a console application that demonstrates basic speech recognition. The example uses input from an audio file, example.wav, that contains the phrases, "testing testing one two three" and "mister cooper", separated by a pause. The example generates the following output.

Starting asynchronous recognition...  
  Recognized text =  Testing testing 123  
  Recognized text =  Mr. Cooper  
  End of stream encountered.  
Done.  

Press any key to exit...  

using System;  
using System.Globalization;  
using System.IO;  
using System.Speech.AudioFormat;  
using System.Speech.Recognition;  
using System.Threading;  

namespace InputExamples  
{  
  class Program  
  {  
    // Indicate whether asynchronous recognition is complete.  
    static bool completed;  

    static void Main(string[] args)  
    {  
      using (SpeechRecognitionEngine recognizer =  
        new SpeechRecognitionEngine(new CultureInfo("en-US")))  
      {  

        // Create and load a grammar.  
        Grammar dictation = new DictationGrammar();  
        dictation.Name = "Dictation Grammar";  

        recognizer.LoadGrammar(dictation);  

        // Configure the input to the recognizer.  
        recognizer.SetInputToAudioStream(  
          File.OpenRead(@"c:\temp\audioinput\example.wav"),  
          new SpeechAudioFormatInfo(  
            44100, AudioBitsPerSample.Sixteen, AudioChannel.Mono));  

        // Attach event handlers.  
        recognizer.SpeechRecognized +=  
          new EventHandler<SpeechRecognizedEventArgs>(  
            SpeechRecognizedHandler);  
        recognizer.RecognizeCompleted +=  
          new EventHandler<RecognizeCompletedEventArgs>(  
            RecognizeCompletedHandler);  

        // Perform recognition of the whole file.  
        Console.WriteLine("Starting asynchronous recognition...");  
        completed = false;  
        recognizer.RecognizeAsync(RecognizeMode.Multiple);  

        while (!completed)  
        {  
          Thread.Sleep(333);  
        }  
        Console.WriteLine("Done.");  
      }  

      Console.WriteLine();  
      Console.WriteLine("Press any key to exit...");  
      Console.ReadKey();  
    }  

    // Handle the SpeechRecognized event.  
    static void SpeechRecognizedHandler(  
      object sender, SpeechRecognizedEventArgs e)  
    {  
      if (e.Result != null && e.Result.Text != null)  
      {  
        Console.WriteLine("  Recognized text =  {0}", e.Result.Text);  
      }  
      else  
      {  
        Console.WriteLine("  Recognized text not available.");  
      }  
    }  

    // Handle the RecognizeCompleted event.  
    static void RecognizeCompletedHandler(  
      object sender, RecognizeCompletedEventArgs e)  
    {  
      if (e.Error != null)  
      {  
        Console.WriteLine("  Error encountered, {0}: {1}",  
          e.Error.GetType().Name, e.Error.Message);  
      }  
      if (e.Cancelled)  
      {  
        Console.WriteLine("  Operation cancelled.");  
      }  
      if (e.InputStreamEnded)  
      {  
        Console.WriteLine("  End of stream encountered.");  
      }  

      completed = true;  
    }  
  }  
}

Remarks

If the recognizer reaches the end of the input stream during a recognition operation, the recognition operation finalizes with the available input. Any subsequent recognition operations can generate an exception, unless you update the input to the recognizer.

Applies to

See also