How to detect when there is some speech near MIC i

Question Statement: I want to start recording when there is some Voice/Noise in vicinity of Phones MIC and stop when user stops speaking. Just Like Talking Tom etc.

Is there any third party library or some native code to do this?

Thanks

回答1:

Just add this code to your application and you will detect when user start to speak and when he stops.

public void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

    // Get the minimum buffer size required for the successful creation of an AudioRecord object. 
    int bufferSizeInBytes = AudioRecord.getMinBufferSize( RECORDER_SAMPLERATE,
                                                          RECORDER_CHANNELS,
                                                          RECORDER_AUDIO_ENCODING
                                                         ); 
    // Initialize Audio Recorder.
    AudioRecord audioRecorder = new AudioRecord( MediaRecorder.AudioSource.MIC,
                                                 RECORDER_SAMPLERATE,
                                                 RECORDER_CHANNELS,
                                                 RECORDER_AUDIO_ENCODING,
                                                 bufferSizeInBytes
                                                );
    // Start Recording.
    audioRecorder.startRecording();

    int numberOfReadBytes   = 0; 
    byte audioBuffer[]      = new  byte[bufferSizeInBytes];
    boolean recording       = false;
    float tempFloatBuffer[] = new float[3];
    int tempIndex           = 0;
    int totalReadBytes      = 0;
    byte totalByteBuffer[]  = new byte[60 * 44100 * 2];


    // While data come from microphone. 
    while( true )
    {
        float totalAbsValue = 0.0f;
        short sample        = 0; 

        numberOfReadBytes = audioRecorder.read( audioBuffer, 0, bufferSizeInBytes );

        // Analyze Sound.
        for( int i=0; i<bufferSizeInBytes; i+=2 ) 
        {
            sample = (short)( (audioBuffer[i]) | audioBuffer[i + 1] << 8 );
            totalAbsValue += Math.abs( sample ) / (numberOfReadBytes/2);
        }

        // Analyze temp buffer.
        tempFloatBuffer[tempIndex%3] = totalAbsValue;
        float temp                   = 0.0f;
        for( int i=0; i<3; ++i )
            temp += tempFloatBuffer[i];

        if( (temp >=0 && temp <= 350) && recording == false )
        {
            Log.i("TAG", "1");
            tempIndex++;
            continue;
        }

        if( temp > 350 && recording == false )
        {
            Log.i("TAG", "2");
            recording = true;
        }

        if( (temp >= 0 && temp <= 350) && recording == true )
        {
            Log.i("TAG", "Save audio to file.");

            // Save audio to file.
            String filepath = Environment.getExternalStorageDirectory().getPath();
            File file = new File(filepath,"AudioRecorder");
            if( !file.exists() )
                file.mkdirs();

            String fn = file.getAbsolutePath() + "/" + System.currentTimeMillis() + ".wav";

            long totalAudioLen  = 0;
            long totalDataLen   = totalAudioLen + 36;
            long longSampleRate = RECORDER_SAMPLERATE;
            int channels        = 1;
            long byteRate       = RECORDER_BPP * RECORDER_SAMPLERATE * channels/8;
            totalAudioLen       = totalReadBytes;
            totalDataLen        = totalAudioLen + 36;
            byte finalBuffer[]  = new byte[totalReadBytes + 44];

            finalBuffer[0] = 'R';  // RIFF/WAVE header
            finalBuffer[1] = 'I';
            finalBuffer[2] = 'F';
            finalBuffer[3] = 'F';
            finalBuffer[4] = (byte) (totalDataLen & 0xff);
            finalBuffer[5] = (byte) ((totalDataLen >> 8) & 0xff);
            finalBuffer[6] = (byte) ((totalDataLen >> 16) & 0xff);
            finalBuffer[7] = (byte) ((totalDataLen >> 24) & 0xff);
            finalBuffer[8] = 'W';
            finalBuffer[9] = 'A';
            finalBuffer[10] = 'V';
            finalBuffer[11] = 'E';
            finalBuffer[12] = 'f';  // 'fmt ' chunk
            finalBuffer[13] = 'm';
            finalBuffer[14] = 't';
            finalBuffer[15] = ' ';
            finalBuffer[16] = 16;  // 4 bytes: size of 'fmt ' chunk
            finalBuffer[17] = 0;
            finalBuffer[18] = 0;
            finalBuffer[19] = 0;
            finalBuffer[20] = 1;  // format = 1
            finalBuffer[21] = 0;
            finalBuffer[22] = (byte) channels;
            finalBuffer[23] = 0;
            finalBuffer[24] = (byte) (longSampleRate & 0xff);
            finalBuffer[25] = (byte) ((longSampleRate >> 8) & 0xff);
            finalBuffer[26] = (byte) ((longSampleRate >> 16) & 0xff);
            finalBuffer[27] = (byte) ((longSampleRate >> 24) & 0xff);
            finalBuffer[28] = (byte) (byteRate & 0xff);
            finalBuffer[29] = (byte) ((byteRate >> 8) & 0xff);
            finalBuffer[30] = (byte) ((byteRate >> 16) & 0xff);
            finalBuffer[31] = (byte) ((byteRate >> 24) & 0xff);
            finalBuffer[32] = (byte) (2 * 16 / 8);  // block align
            finalBuffer[33] = 0;
            finalBuffer[34] = RECORDER_BPP;  // bits per sample
            finalBuffer[35] = 0;
            finalBuffer[36] = 'd';
            finalBuffer[37] = 'a';
            finalBuffer[38] = 't';
            finalBuffer[39] = 'a';
            finalBuffer[40] = (byte) (totalAudioLen & 0xff);
            finalBuffer[41] = (byte) ((totalAudioLen >> 8) & 0xff);
            finalBuffer[42] = (byte) ((totalAudioLen >> 16) & 0xff);
            finalBuffer[43] = (byte) ((totalAudioLen >> 24) & 0xff);

            for( int i=0; i<totalReadBytes; ++i )
                finalBuffer[44+i] = totalByteBuffer[i];

            FileOutputStream out;
            try {
                out = new FileOutputStream(fn);
                 try {
                        out.write(finalBuffer);
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

            } catch (FileNotFoundException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

            //*/
            tempIndex++;
            break;
        }

        // -> Recording sound here.
        Log.i( "TAG", "Recording Sound." );
        for( int i=0; i<numberOfReadBytes; i++ )
            totalByteBuffer[totalReadBytes + i] = audioBuffer[i];
        totalReadBytes += numberOfReadBytes;
        //*/

        tempIndex++;

    }
}

Check this link.

The above code is refered from SO Post.

回答2:

There are some things in this code to change IF YOU WANT TO HAVE IT RUNNING continuously like Talking Tom etc.

You need to delete the breake; statement from while(true) loop.
Stop audioRecorder.stop();, then save audio data to file and play it (if you want).

Clear out the previous buffers and indexes after saving data to a file to insure that, this data will not be used again. i.e

        recording = false;
        tempIndex = 0;
        audioBuffer = null;
        totalByteBuffer = null;
        audioBuffer = new  byte[bufferSizeInBytes];
        totalByteBuffer = new byte[60 * 44100 * 2];
        totalReadBytes = 0;

Start RecorderaudioRecorder.startRecording(); This will insure that Recorder will not record the audio being Played.
Delete the previous created file after playing it.