Android之录音功能

1.需要权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />

2.检查权限

// 需要申请的运行时权限
private String[] permissions = new String[]{
    
        Manifest.permission.RECORD_AUDIO,
        Manifest.permission.WRITE_EXTERNAL_STORAGE
};
// 检查权限
private void checkPermissions() {
    
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    
        for (int i = 0; i < permissions.length; i++) {
    
            if (ContextCompat.checkSelfPermission(this, permissions[i]) !=
                    PackageManager.PERMISSION_GRANTED) {
    
                mPermissionList.add(permissions[i]);
            }
        }
        if (!mPermissionList.isEmpty()) {
    
            String[] permissions = mPermissionList.toArray(new String[mPermissionList.size()]);
            ActivityCompat.requestPermissions(this, permissions, MY_PERMISSIONS_REQUEST);
        }
    }
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    
    if (requestCode == MY_PERMISSIONS_REQUEST) {
    
        for (int i = 0; i < grantResults.length; i++) {
    
            if (grantResults[i] != PackageManager.PERMISSION_GRANTED) {
    
                Log.i(TAG, permissions[i] + " 权限被用户禁止！");
            }
        }
        // 运行时权限的申请不是本demo的重点，所以不再做更多的处理，请同意权限申请。
    }
}

3.创建/终止工作线程

// 创建
handlerThread = new HandlerThread("handlerThread");
handlerThread.start();
workHandler = new Handler(handlerThread.getLooper());
// 终止
handlerThread.quit();
workHandler.removeCallbacksAndMessages(null);

4.开始录音

// 采样率，现在能够保证在所有设备上使用的采样率是44100Hz, 但是其他的采样率（22050, 16000, 11025）在一些设备上也可以使用。
public static final int SAMPLE_RATE_INHZ = 44100;
// 声道数。CHANNEL_IN_MONO and CHANNEL_IN_STEREO. 其中CHANNEL_IN_MONO是可以保证在所有设备能够使用的。
public static final int CHANNEL_CONFIG = AudioFormat.CHANNEL_IN_MONO;
// 返回的音频数据的格式。 ENCODING_PCM_8BIT, ENCODING_PCM_16BIT, and ENCODING_PCM_FLOAT.
public static final int AUDIO_FORMAT = AudioFormat.ENCODING_PCM_16BIT;

// 开始录音
private void startRecord() {
    
   // 获取最小录音缓存大小，
   final int minBufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE_INHZ, CHANNEL_CONFIG, AUDIO_FORMAT);
   audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE_INHZ,
           CHANNEL_CONFIG, AUDIO_FORMAT, minBufferSize);
   // 初始化缓存
   final byte[] data = new byte[minBufferSize];
   final File file = new File(getExternalFilesDir(Environment.DIRECTORY_MUSIC), "hello/test.pcm");
   Log.i(TAG, "path:" + file.getAbsolutePath());
   tvRecordFilePosition.setText("文件位置："+file.getAbsolutePath());
   if(!createFile(file)) return;
   // 开始录音
   audioRecord.startRecording();
   isRecording = true;
   // 创建数据流，将缓存导入数据流
   workHandler.post(new Runnable() {
    
       @Override
       public void run() {
    
           FileOutputStream fos = null;
           try {
    
               fos = new FileOutputStream(file);
           } catch (FileNotFoundException e) {
    
               e.printStackTrace();
               Log.e(TAG, "文件未找到");
           }
           if (fos == null) return;
           while (isRecording) {
    
               int length = audioRecord.read(data, 0, minBufferSize);
               if (AudioRecord.ERROR_INVALID_OPERATION != length) {
    
                   try {
    
                       fos.write(data, 0, length);
                   } catch (IOException e) {
    
                       e.printStackTrace();
                   }
               }
           }
           try {
    
               // 关闭数据流
               fos.close();
           } catch (IOException e) {
    
               e.printStackTrace();
           }
       }
   });
}

5.停止录音

// 停止录音
private void stopRecord() {
    
    isRecording = false;
    if (audioRecord != null) {
    
        audioRecord.stop();
        audioRecord.release();
        audioRecord = null;
    }
}