Android录音时获取分贝值的方法代码实例

时间:2022-09-23 17:52:25

参考文章Android中实时获取音量分贝值详解:http://www.zzvips.com/article/64806.htm

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public class MediaRecorderDemo {
  private final String TAG = "MediaRecord";
  private MediaRecorder mMediaRecorder;
  public static final int MAX_LENGTH = 1000 * 60 * 10;// 最大录音时长1000*60*10;
  private String filePath;
 
  public MediaRecorderDemo(){
    this.filePath = "/dev/null";
  }
 
  public MediaRecorderDemo(File file) {
    this.filePath = file.getAbsolutePath();
  }
 
  private long startTime;
  private long endTime;
 
  /**
   * 开始录音 使用amr格式
   *
   *      录音文件
   * @return
   */
  public void startRecord() {
    // 开始录音
    /* ①Initial:实例化MediaRecorder对象 */
    if (mMediaRecorder == null)
      mMediaRecorder = new MediaRecorder();
    try {
      /* ②setAudioSource/setVedioSource */
      mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);// 设置麦克风
      /* ②设置音频文件的编码:AAC/AMR_NB/AMR_MB/Default 声音的(波形)的采样 */
      mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
            /*
       * ②设置输出文件的格式:THREE_GPP/MPEG-4/RAW_AMR/Default THREE_GPP(3gp格式
       * ,H263视频/ARM音频编码)、MPEG-4、RAW_AMR(只支持音频且音频编码要求为AMR_NB)
       */
      mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
 
      /* ③准备 */
      mMediaRecorder.setOutputFile(filePath);
      mMediaRecorder.setMaxDuration(MAX_LENGTH);
      mMediaRecorder.prepare();
      /* ④开始 */
      mMediaRecorder.start();
      // AudioRecord audioRecord.
      /* 获取开始时间* */
      startTime = System.currentTimeMillis();
      updateMicStatus();
      Log.i("ACTION_START", "startTime" + startTime);
    } catch (IllegalStateException e) {
      Log.i(TAG,
          "call startAmr(File mRecAudioFile) failed!"
              + e.getMessage());
    } catch (IOException e) {
      Log.i(TAG,
          "call startAmr(File mRecAudioFile) failed!"
              + e.getMessage());
    }
  }
 
  /**
   * 停止录音
   *
   */
  public long stopRecord() {
    if (mMediaRecorder == null)
      return 0L;
    endTime = System.currentTimeMillis();
    Log.i("ACTION_END", "endTime" + endTime);
    mMediaRecorder.stop();
    mMediaRecorder.reset();
    mMediaRecorder.release();
    mMediaRecorder = null;
    Log.i("ACTION_LENGTH", "Time" + (endTime - startTime));
    return endTime - startTime;
  }
 
  private final Handler mHandler = new Handler();
  private Runnable mUpdateMicStatusTimer = new Runnable() {
    public void run() {
      updateMicStatus();
    }
  };
 
  /**
   * 更新话筒状态
   *
   */
  private int BASE = 1;
  private int SPACE = 100;// 间隔取样时间
 
  private void updateMicStatus() {
    if (mMediaRecorder != null) {
      double ratio = (double)mMediaRecorder.getMaxAmplitude() /BASE;
      double db = 0;// 分贝
      if (ratio > 1)
        db = 20 * Math.log10(ratio);
      Log.d(TAG,"分贝值:"+db);
      mHandler.postDelayed(mUpdateMicStatusTimer, SPACE);
    }
  }
}