如何在 Android 中使用 AudioRecorder 录制音频

Question

我想从 Android 设备捕获音频。我下面的代码似乎成功地在 SD 卡上制作了 wav 文件，但无法播放。我尝试使用不同的媒体播放器播放它，但没有奏效。我的代码中存在导致此问题的问题。

代码

public class MainActivity extends ActionBarActivity {

    private static final String LOG_TAG = "AudioRecordTest";

    static final int AUDIO_PORT = 2048;
    static final int SAMPLE_RATE = 8000;
    static final int SAMPLE_INTERVAL = 20; // milliseconds
    static final int SAMPLE_SIZE = 2; // bytes per sample
    static final int BUF_SIZE = SAMPLE_INTERVAL * SAMPLE_INTERVAL * SAMPLE_SIZE * 2;

    private static int[] mSampleRates = new int[]{44100, 44056, 47250, 48000, 22050, 16000, 11025, 8000};
    private Thread recordingThread = null;
    private boolean isRecording = false;

    int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we
    // use only 1024
    int BytesPerElement = 2; // 2 bytes in 16bit format

    private int bufferSize;

    private AudioRecord recorder;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startRecording();
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


    private void startRecording() {

        recorder = findAudioRecord();

        recorder.startRecording();
        isRecording = true;
        recordingThread = new Thread(new Runnable() {
            public void run() {
                writeAudioDataToFile();
            }
        }, "AudioRecorder Thread");
        recordingThread.start();
    }

    // convert short to byte
    private byte[] short2byte(short[] sData) {
        int shortArrsize = sData.length;
        byte[] bytes = new byte[shortArrsize * 2];
        for (int i = 0; i < shortArrsize; i++) {
            bytes[i * 2] = (byte) (sData[i] & 0x00FF);
            bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);
            sData[i] = 0;
        }
        return bytes;

    }

    public AudioRecord findAudioRecord() {
        for (int rate : mSampleRates) {
            for (short audioFormat : new short[]{AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT}) {
                for (short channelConfig : new short[]{AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO}) {
                    try {
                        Log.d(LOG_TAG, "Attempting rate " + rate + "Hz, bits: " + audioFormat + ", channel: "
                                + channelConfig);
                        bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                        if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                            // check if we can instantiate and have a success
                            recorder = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, rate, channelConfig, audioFormat, bufferSize);
                            if (recorder.getState() == AudioRecord.STATE_INITIALIZED)
                                return recorder;
                        }
                    } catch (Exception e) {
                        Log.e(LOG_TAG, rate + "Exception, keep trying.", e);
                    }
                }
            }
        }
        return null;
    }

    private void writeAudioDataToFile() {
        /*// Write the output audio in byte
        short sData[] = new short[BufferElements2Rec];

        while (isRecording) {
            // gets the voice output from microphone to byte format
            recorder.read(sData, 0, BufferElements2Rec);
            System.out.println("Short wirting to file" + sData.toString());
            // // stores the voice buffer
            byte bData[] = short2byte(sData);
            sendLiveAudio(bData);
        }*/

        String filePath = "/sdcard/test.wav";
        short sData[] = new short[bufferSize / 2];

        FileOutputStream os = null;
        try {
            os = new FileOutputStream(filePath);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        while (isRecording) {
            // gets the voice output from microphone to byte format

            recorder.read(sData, 0, bufferSize / 2);
            Log.d("eray", "Short wirting to file" + sData.toString());
            try {
                // // writes the data to file from buffer
                // // stores the voice buffer
                byte bData[] = short2byte(sData);
                os.write(bData, 0, bufferSize);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {
            os.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void stopRecording() {
        // stops the recording activity
        if (null != recorder) {
            isRecording = false;
            recorder.stop();
            recorder.release();
            recorder = null;
            recordingThread = null;
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }


    @Override
    public void onBackPressed() {
        super.onBackPressed();
        stopRecording();
    }


}

Answer 1

试试这个.....

public class Audio_Record extends Activity {
private static final int RECORDER_SAMPLERATE = 8000;
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private AudioRecord recorder = null;
private Thread recordingThread = null;
private boolean isRecording = false;

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

    setButtonHandlers();
    enableButtons(false);

    int bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,
            RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING); 
}

private void setButtonHandlers() {
    ((Button) findViewById(R.id.btnStart)).setOnClickListener(btnClick);
    ((Button) findViewById(R.id.btnStop)).setOnClickListener(btnClick);
}

private void enableButton(int id, boolean isEnable) {
    ((Button) findViewById(id)).setEnabled(isEnable);
}

private void enableButtons(boolean isRecording) {
    enableButton(R.id.btnStart, !isRecording);
    enableButton(R.id.btnStop, isRecording);
}

int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024
int BytesPerElement = 2; // 2 bytes in 16bit format

private void startRecording() {

    recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
            RECORDER_SAMPLERATE, RECORDER_CHANNELS,
            RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement);

    recorder.startRecording();
    isRecording = true;
    recordingThread = new Thread(new Runnable() {
        public void run() {
            writeAudioDataToFile();
        }
    }, "AudioRecorder Thread");
    recordingThread.start();
}

    //convert short to byte
private byte[] short2byte(short[] sData) {
    int shortArrsize = sData.length;
    byte[] bytes = new byte[shortArrsize * 2];
    for (int i = 0; i < shortArrsize; i++) {
        bytes[i * 2] = (byte) (sData[i] & 0x00FF);
        bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);
        sData[i] = 0;
    }
    return bytes;

}

private void writeAudioDataToFile() {
    // Write the output audio in byte

    String filePath = "/sdcard/voice8K16bitmono.pcm";
    short sData[] = new short[BufferElements2Rec];

    FileOutputStream os = null;
    try {
        os = new FileOutputStream(filePath);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    while (isRecording) {
        // gets the voice output from microphone to byte format

        recorder.read(sData, 0, BufferElements2Rec);
        System.out.println("Short wirting to file" + sData.toString());
        try {
            // // writes the data to file from buffer
            // // stores the voice buffer
            byte bData[] = short2byte(sData);
            os.write(bData, 0, BufferElements2Rec * BytesPerElement);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    try {
        os.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

private void stopRecording() {
    // stops the recording activity
    if (null != recorder) {
        isRecording = false;
        recorder.stop();
        recorder.release();
        recorder = null;
        recordingThread = null;
    }
}

private View.OnClickListener btnClick = new View.OnClickListener() {
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.btnStart: {
            enableButtons(true);
            startRecording();
            break;
        }
        case R.id.btnStop: {
            enableButtons(false);
            stopRecording();
            break;
        }
        }
    }
};

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        finish();
    }
    return super.onKeyDown(keyCode, event);
}
}