Android AudioRecord example

Question

我正在设计一个Android应用程序，我需要实现一个AudioRecord类来记录用户的声音。经过一些研究(没有提供足够的信息)和一些失败的尝试，我想知道是否有人可以通过张贴一个例子(代码)来帮助我如何使用AudioRecord捕获高质量的声音。我真的很感激。谢谢你

Answer 1

我在这里发布了一些代码示例，使用AudioRecord API记录良好的声音质量。

注意:如果你在模拟器中使用，声音质量不会很好，因为我们使用的是只支持模拟器的8k采样率。在设备中使用44.1k的采样率以获得更好的质量。

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 writing 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);
    }
}

有关更多详细信息，请参阅AUDIORECORD BLOG。

Answer 2

这是一个端到端解决方案，我实现流式Android麦克风音频到服务器播放:Android AudioRecord到服务器通过UDP播放问题