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RecognizedAudio.GetRange(TimeSpan, TimeSpan) Method

  • Reference

Definition

Namespace:
System.Speech.Recognition
Assembly:
System.Speech.dll
Package:
System.Speech v9.0.0
Source:
RecognizedAudio.cs
Source:
RecognizedAudio.cs
Source:
RecognizedAudio.cs

Selects and returns a section of the current recognized audio as binary data.

public:
 System::Speech::Recognition::RecognizedAudio ^ GetRange(TimeSpan audioPosition, TimeSpan duration);
public System.Speech.Recognition.RecognizedAudio GetRange (TimeSpan audioPosition, TimeSpan duration);
member this.GetRange : TimeSpan * TimeSpan -> System.Speech.Recognition.RecognizedAudio
Public Function GetRange (audioPosition As TimeSpan, duration As TimeSpan) As RecognizedAudio

Parameters

audioPosition
TimeSpan

The starting point of the audio data to be returned.

duration
TimeSpan

The length of the segment to be returned.

Returns

RecognizedAudio

Returns a subsection of the recognized audio, as defined by audioPosition and duration.

Exceptions

ArgumentOutOfRangeException

audioPosition and duration define a segment of audio outside the range of the current segment.

InvalidOperationException

The current recognized audio contains no data.

Examples

The following example creates a speech recognition grammar for name input, adds a handler for the SpeechRecognized event, and loads the grammar into an in-process speech recognizer. Then it writes the audio information for the name portion of the input to an audio file. The audio file is used as input to a SpeechSynthesizer object, which speaks a phrase that includes the recorded audio.

private static void AddNameGrammar(SpeechRecognitionEngine recognizer)  
{  
  GrammarBuilder builder = new GrammarBuilder();  
  builder.Append("My name is");  
  builder.AppendWildcard();  

  Grammar nameGrammar = new Grammar(builder);  
  nameGrammar.Name = "Name Grammar";  
  nameGrammar.SpeechRecognized +=  
    new EventHandler<SpeechRecognizedEventArgs>(  
      NameSpeechRecognized);  

  recognizer.LoadGrammar(nameGrammar);  
}  

// Handle the SpeechRecognized event of the name grammar.  
private static void NameSpeechRecognized(  
  object sender, SpeechRecognizedEventArgs e)  
{  
  Console.WriteLine("Grammar ({0}) recognized speech: {1}",  
    e.Result.Grammar.Name, e.Result.Text);  

  try  
  {  

    // The name phrase starts after the first three words.  
    if (e.Result.Words.Count < 4)  
    {  

      // Add code to check for an alternate that contains the wildcard.  
      return;  
    }  

    RecognizedAudio audio = e.Result.Audio;  
    TimeSpan start = e.Result.Words[3].AudioPosition;  
    TimeSpan duration = audio.Duration - start;  

    // Add code to verify and persist the audio.  
    string path = @"C:\temp\nameAudio.wav";  
    using (Stream outputStream = new FileStream(path, FileMode.Create))  
    {  
      RecognizedAudio nameAudio = audio.GetRange(start, duration);  
      nameAudio.WriteToWaveStream(outputStream);  
      outputStream.Close();  
    }  

    Thread testThread =  
      new Thread(new ParameterizedThreadStart(TestAudio));  
    testThread.Start(path);  
  }  
  catch (Exception ex)  
  {  
    Console.WriteLine("Exception thrown while processing audio:");  
    Console.WriteLine(ex.ToString());  
  }  
}  

// Use the speech synthesizer to play back the .wav file  
// that was created in the SpeechRecognized event handler.  

private static void TestAudio(object item)  
{  
  string path = item as string;  
  if (path != null && File.Exists(path))  
  {  
    SpeechSynthesizer synthesizer = new SpeechSynthesizer();  
    PromptBuilder builder = new PromptBuilder();  
    builder.AppendText("Hello");  
    builder.AppendAudio(path);  
    synthesizer.Speak(builder);  
  }  
}

Applies to

See also