Android speech - how can you read text in Android?

Question

How can you read data, i.e. convert simple text strings to voice (speech) in Android?

Is there an API where I can do something like this:

TextToVoice         


        

Answer 1

Using the TTS is a little bit more complicated than you expect, but it's easy to write a wrapper that gives you the API you desire.

There are a number of issues you must overcome to get it work nicely.

They are:

1. Always set the UtteranceId (or else OnUtteranceCompleted will not be called)
2. setting OnUtteranceCompleted listener (only after the speech system is properly initialized)

public class TextSpeakerDemo implements OnInitListener
 {
    private TextToSpeech tts;
    private Activity activity;

    private static HashMap DUMMY_PARAMS = new HashMap();
    static 
    {
        DUMMY_PARAMS.put(TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID, "theUtId");
    }
    private ReentrantLock waitForInitLock = new ReentrantLock();

    public TextSpeakerDemo(Activity parentActivity)
    {
        activity = parentActivity;
        tts = new TextToSpeech(activity, this);       
        //don't do speak until initing
        waitForInitLock.lock();
    }

    public void onInit(int version)
    {        //unlock it so that speech will happen
        waitForInitLock.unlock();
    }  

    public void say(WhatToSay say)
    {
        say(say.toString());
    }

    public void say(String say)
    {
        tts.speak(say, TextToSpeech.QUEUE_FLUSH, null);
    }

    public void say(String say, OnUtteranceCompletedListener whenTextDone)
    {
        if (waitForInitLock.isLocked())
        {
            try
            {
                waitForInitLock.tryLock(180, TimeUnit.SECONDS);
            }
            catch (InterruptedException e)
            {
                Log.e("speaker", "interruped");
            }
            //unlock it here so that it is never locked again
            waitForInitLock.unlock();
        }

        int result = tts.setOnUtteranceCompletedListener(whenTextDone);
        if (result == TextToSpeech.ERROR)
        {
            Log.e("speaker", "failed to add utterance listener");
        }
        //note: here pass in the dummy params so onUtteranceCompleted gets called
        tts.speak(say, TextToSpeech.QUEUE_FLUSH, DUMMY_PARAMS);
    }

    /**
     * make sure to call this at the end
     */
    public void done()
    {
        tts.shutdown();
    }
}