SpeechAPI

Java API

To get started with the java api, it is recommended that you download the cli and take a look at the cli source code as examples. You can also use the cli project as a starting point. It has all the required jars and a basic ant script.

To decode an audio file simply use this code:



   //setup the paramters to the recognize call

   String GrammarUrl=file:///
   Boolean lmflag=false;
   Boolean doEndpointing = true;
   boolean batch = false;
   String audioFileName ="c:/audio/audofile.wav";

   //set up you http recognizer and point it to the speech cloud server
   String Service = http://www.spokentech.com/speechcloud/SpeechUploadServlet";
   HttpRecognizer recog = new HttpRecognizer();
   recog.setService(service);

   //Do the recognition (will block until result is determined)
   RecognitionResult r = recog.recognize(audioFileName, grammarUrl, 
                                         lmflg, doEndpointing, batch);
   System.out.println("Result: "+r.getText());

If you have a stream, rather than a file you can use the recognize method that takes an AudioInputStream rather than a File. Note you may need to take care to do endpointing depending on the nature of your stream. The endpointing flag will do endpointing on the server. But your stream must be closed for a response to be returned. This is one reason the client side endpointing is a good choice.


   AudioInputStream stream = getStreamFromSomewhere(...);

   //Do the recognition (will block until result is determined)
   RecognitionResult r = recog.recognize(stream, grammarUrl, lmflg, doEndpointing, batch);
   System.out.println("Result: "+r.getText());

To decode audio from your microphone and use the client side endpointer, You can use the same httprecognizer object, but use the method that takes an endpointing stream. In this case create a micS4endpointingstream. Once setup and initialized it will start the http requests when speech is detected and start streaming the audio as an http attachment. It will close the stream when it detects the end of speech.


   //create an setup the endpointing stream
   //constructing the endpointingstream using the Sphinx4 frontend endpointer
   S4EndPointer ep = new S4EndPointer();
   MicS4EndPointingInputStream epStream = new MicS4EndPointingInputStream(ep);

   // use 8khz 16 bit audio
   AudioFormat format = new AudioFormat(8000,

   // Use this mimetype when using the s4 endpointer
   String mimeType = "audio/x-s4audio";
   
   //set up the stream (now its checking for start/end speech signals)
   epStream.setupStream(format, mimeType);

   //setup the http recognizer
   HttpRecognizer recog = new HttpRecognizer();
   recog.setService(service);

   //Start recognition.  Blocks until a result
   RecognitionResult r = null;
   try {	            
       r = recog.recognize(grammarUrl,  epStream,  lmflag,  timeout) ;
   } catch (InstantiationException e) {
       // TODO Auto-generated catch block
      e.printStackTrace();
   } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();      
   }
    	
   //print the results text
   if (r == null) {
       System.out.println("null result");
   } else {
       System.out.println("result: "+r.getText());	 
   }

You can do end pointing on the client for streams and files in a similar manner use StreamS4EndPointingInputStream FileS4EndPointingInputStream in place of the MicS4EndPointingInputStream in the example above.

This example uses the cloud synthesizer to create audio for a text string.


    //Setup the http synthesizer
    String service = "http://www.spokentech.net/speechcloud/SpeechDownloadServlet";  
	HttpSynthesizer synth = new HttpSynthesizer();
	synth.setService(service);	 
		    		    	
	//create the input parameters
	AudioFormat format = new AudioFormat (sampleRate, sampleSizeInBits, channels, 
	                                      signed, bigEndian);		      
	String text = "this is a only a test";
	String voice = "jmk-arctic";
	String outFileName = "this-is.wav";
	    	
	//synthesize!
	OutputStream stream = synth.synthesize(text, format, wav, voice);

Out of the box Endpointers

The speechcloud java client comes with 3 endpointers

S4Endpointer -- use the sphinx4 fronte end endpointers
ExternalTriggerendPointer -- requires external triggers to indicates start and end speech
AudioStreamEndPointer -- simple endpointer

Both externalTriggeredEndpointer nad AudioStreamEndpointer send audio in wav format set mime type to "audio/x-wav" whne using them.

Custom Endpointer

You can write your own custom endpointer that will work with endpointing streams.

extend BaseEndpointer
implement doEndpinting() method

In the do endpointing method you read from inputStream, check for startSpeech condition, when startSpeech occurs you must copy data to the outputStream. You must close the outpustream when the endspeech condition occurs.

Doing feature extraction on the client

You can configre the S4 endpointer do feature extraction on the client by setting the mimetype to "audio/x-s4feature".

RTP Streams

To be specified.