Android 4.1 和 4.2 上的 Android 语音识别即服务

Question

我已经成功地将连续语音识别工作（使用 SpeechRecognizer 类）作为服务在所有 Android 版本（最高 4.1）上运行。 我的问题涉及让它在 4.1 和 4.2 版本上工作，因为众所周知，存在一个问题，即在语音识别开始几秒钟后，API 没有按照文档中的说明执行，如果没有检测到语音输入，则它就像如果语音识别器无声地死亡。 （ http://code.google.com/p/android/issues/detail?id=37883 ）

我发现了一个问题，该问题提出了解决此问题的方法（ 语音识别在几秒钟后停止侦听），但我不确定如何实现此解决方案所需的处理程序。 我知道这种变通方法会导致每隔几秒钟发出一次“哔哔声”，但获得持续的语音识别对我来说更为重要。

如果有人有任何其他替代解决方法，那么我也想听听。

Answer 1

这是 android 版本 4.1.1 的变通方法。

public class MyService extends Service
{
    protected AudioManager mAudioManager; 
    protected SpeechRecognizer mSpeechRecognizer;
    protected Intent mSpeechRecognizerIntent;
    protected final Messenger mServerMessenger = new Messenger(new IncomingHandler(this));

    protected boolean mIsListening;
    protected volatile boolean mIsCountDownOn;
    private boolean mIsStreamSolo;

    static final int MSG_RECOGNIZER_START_LISTENING = 1;
    static final int MSG_RECOGNIZER_CANCEL = 2;

    @Override
    public void onCreate()
    {
        super.onCreate();
        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE); 
        mSpeechRecognizer = SpeechRecognizer.createSpeechRecognizer(this);
        mSpeechRecognizer.setRecognitionListener(new SpeechRecognitionListener());
        mSpeechRecognizerIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
        mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,
                                         RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
        mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE,
                                         this.getPackageName());
    }

    protected static class IncomingHandler extends Handler
    {
        private WeakReference<MyService> mtarget;

        IncomingHandler(MyService target)
        {
            mtarget = new WeakReference<MyService>(target);
        }


        @Override
        public void handleMessage(Message msg)
        {
            final MyService target = mtarget.get();

            switch (msg.what)
            {
                case MSG_RECOGNIZER_START_LISTENING:

                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
                    {
                        // turn off beep sound  
                        if (!mIsStreamSolo)
                        {
                            mAudioManager.setStreamSolo(AudioManager.STREAM_VOICE_CALL, true);
                            mIsStreamSolo = true;
                        }
                    }
                     if (!target.mIsListening)
                     {
                         target.mSpeechRecognizer.startListening(target.mSpeechRecognizerIntent);
                         target.mIsListening = true;
                        //Log.d(TAG, "message start listening"); //$NON-NLS-1$
                     }
                     break;

                 case MSG_RECOGNIZER_CANCEL:
                    if (mIsStreamSolo)
                   {
                        mAudioManager.setStreamSolo(AudioManager.STREAM_VOICE_CALL, false);
                        mIsStreamSolo = false;
                   }
                      target.mSpeechRecognizer.cancel();
                      target.mIsListening = false;
                      //Log.d(TAG, "message canceled recognizer"); //$NON-NLS-1$
                      break;
             }
       } 
    } 

    // Count down timer for Jelly Bean work around
    protected CountDownTimer mNoSpeechCountDown = new CountDownTimer(5000, 5000)
    {

        @Override
        public void onTick(long millisUntilFinished)
        {
            // TODO Auto-generated method stub

        }

        @Override
        public void onFinish()
        {
            mIsCountDownOn = false;
            Message message = Message.obtain(null, MSG_RECOGNIZER_CANCEL);
            try
            {
                mServerMessenger.send(message);
                message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);
                mServerMessenger.send(message);
            }
            catch (RemoteException e)
            {

            }
        }
    };

    @Override
    public void onDestroy()
    {
        super.onDestroy();

        if (mIsCountDownOn)
        {
            mNoSpeechCountDown.cancel();
        }
        if (mSpeechRecognizer != null)
        {
            mSpeechRecognizer.destroy();
        }
    }

    protected class SpeechRecognitionListener implements RecognitionListener
    {

        @Override
        public void onBeginningOfSpeech()
        {
            // speech input will be processed, so there is no need for count down anymore
            if (mIsCountDownOn)
            {
                mIsCountDownOn = false;
                mNoSpeechCountDown.cancel();
            }               
            //Log.d(TAG, "onBeginingOfSpeech"); //$NON-NLS-1$
        }

        @Override
        public void onBufferReceived(byte[] buffer)
        {

        }

        @Override
        public void onEndOfSpeech()
        {
            //Log.d(TAG, "onEndOfSpeech"); //$NON-NLS-1$
         }

        @Override
        public void onError(int error)
        {
            if (mIsCountDownOn)
            {
                mIsCountDownOn = false;
                mNoSpeechCountDown.cancel();
            }
             mIsListening = false;
             Message message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);
             try
             {
                    mServerMessenger.send(message);
             }
             catch (RemoteException e)
             {

             }
            //Log.d(TAG, "error = " + error); //$NON-NLS-1$
        }

        @Override
        public void onEvent(int eventType, Bundle params)
        {

        }

        @Override
        public void onPartialResults(Bundle partialResults)
        {

        }

        @Override
        public void onReadyForSpeech(Bundle params)
        {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
            {
                mIsCountDownOn = true;
                mNoSpeechCountDown.start();

            }
            Log.d(TAG, "onReadyForSpeech"); //$NON-NLS-1$
        }

        @Override
        public void onResults(Bundle results)
        {
            //Log.d(TAG, "onResults"); //$NON-NLS-1$

        }

        @Override
        public void onRmsChanged(float rmsdB)
        {

        }

    }
}

02/16/2013 - 如果您在应用程序中使用 Text To Speech 修复哔声，请确保关闭 onResults 中的 Solo 流

Answer 2

如果你真的想在没有互联网连接的情况下实现连续监听，你需要考虑第三方包，其中之一是 CMUSphinx，查看Pocketsphinx android 演示，例如如何在离线状态下有效地监听关键字并对特定命令做出反应，比如关键短语“哦，强大的电脑”。 执行此操作的代码很简单：

您创建一个识别器并添加关键字发现搜索：

recognizer = defaultSetup()
        .setAcousticModel(new File(modelsDir, "hmm/en-us-semi"))
        .setDictionary(new File(modelsDir, "lm/cmu07a.dic"))
        .setKeywordThreshold(1e-5f)
        .getRecognizer();

recognizer.addListener(this);
recognizer.addKeywordSearch(KWS_SEARCH_NAME, KEYPHRASE);
switchSearch(KWS_SEARCH_NAME);

并定义一个监听器：

@Override
public void onPartialResult(Hypothesis hypothesis) {
    String text = hypothesis.getHypstr();
    if (text.equals(KEYPHRASE))
      //  do something
} 

Answer 3

对于任何试图使哔声静音的人，重新分级 @HoanNguyen 的答案，这是非常好的，但要小心，如 api 集中所说，setStreamSolo 是累积性的，因此如果语音识别中出现错误，则调用错误（例如没有互联网连接）然后 setStremSolo true 被一次又一次地调用，这将导致您的应用程序使整个手机静音（非常糟糕）！ 解决方案是将 setStremMute(false) 添加到 SpeechRecognizer onError 中。

Answer 4

查看我的演示应用程序： https : //github.com/galrom/ContinuesVoiceRecognition

我建议同时使用 PockeySphix 和 SpeechRecognizer。