Android 4.1 和 4.2 上的 Android 語音識別即服務

Question

我已經成功地將連續語音識別工作（使用 SpeechRecognizer 類）作為服務在所有 Android 版本（最高 4.1）上運行。 我的問題涉及讓它在 4.1 和 4.2 版本上工作，因為眾所周知，存在一個問題，即在語音識別開始幾秒鍾后，API 沒有按照文檔中的說明執行，如果沒有檢測到語音輸入，則它就像如果語音識別器無聲地死亡。 （ http://code.google.com/p/android/issues/detail?id=37883 ）

我發現了一個問題，該問題提出了解決此問題的方法（ 語音識別在幾秒鍾后停止偵聽），但我不確定如何實現此解決方案所需的處理程序。 我知道這種變通方法會導致每隔幾秒鍾發出一次“嗶嗶聲”，但獲得持續的語音識別對我來說更為重要。

如果有人有任何其他替代解決方法，那么我也想聽聽。

Answer 1

這是 android 版本 4.1.1 的變通方法。

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 - 如果您在應用程序中使用 Text To Speech 修復嗶聲，請確保關閉 onResults 中的 Solo 流

Answer 2

如果你真的想在沒有互聯網連接的情況下實現連續監聽，你需要考慮第三方包，其中之一是 CMUSphinx，查看Pocketsphinx android 演示，例如如何在離線狀態下有效地監聽關鍵字並對特定命令做出反應，比如關鍵短語“哦，強大的電腦”。 執行此操作的代碼很簡單：

您創建一個識別器並添加關鍵字發現搜索：

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);

並定義一個監聽器：

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

Answer 3

對於任何試圖使嗶聲靜音的人，重新分級 @HoanNguyen 的答案，這是非常好的，但要小心，如 api 集中所說，setStreamSolo 是累積性的，因此如果語音識別中出現錯誤，則調用錯誤（例如沒有互聯網連接）然后 setStremSolo true 被一次又一次地調用，這將導致您的應用程序使整個手機靜音（非常糟糕）！ 解決方案是將 setStremMute(false) 添加到 SpeechRecognizer onError 中。

Answer 4

查看我的演示應用程序： https : //github.com/galrom/ContinuesVoiceRecognition

我建議同時使用 PockeySphix 和 SpeechRecognizer。