Android MediaRecorder與AudioRecord音頻錄制

MediaRecorder

AudioRecord

1. 需要的權限

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

/**
   * 開始錄音
   */
  class startRecordListener implements OnClickListener {

    @Override public void onClick(View v) {
      try {
        MediaRecorder mRecorder = new MediaRecorder();
        // 設定聲音源為麥克風
        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        // 設定輸出格式為3gp
        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        // 設定輸出檔案路徑，mFileName為錄音音頻輸出路徑
        mRecorder.setOutputFile(mFileName);
        // 設定聲音解碼AMR_NB
        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        // 媒體錄制器準備
        mRecorder.prepare();
        // 開始錄制
        mRecorder.start();
      } catch (IOException e) {
      }
    }
  }

  /**
   * 停止錄音
   */
  class stopRecordListener implements OnClickListener {

    @Override public void onClick(View v) {
      mRecorder.stop();
      mRecorder.release();
      mRecorder = null;
    }
  }
           

2.AudioRecord

AudioRecord錄音步驟：
1.    建立一個資料流。
2.    構造一個AudioRecord對象，其中需要的最小錄音緩存buffer大小可以通過getMinBufferSize方法得到。如果buffer容量過小，将導緻對象構造的失敗。
3.    初始化一個buffer，該buffer大于等于AudioRecord對象用于寫聲音資料的buffer大小。
4.    開始錄音。
5.    從AudioRecord中讀取聲音資料到初始化buffer，将buffer中資料導入資料流。
6.    停止錄音。
7.    關閉資料流。
           

錄音代碼：

/**
   * 錄音,需要在新的線程中執行，防止主線程阻塞
   */
  private void record() {
    int frequency = 11025;
    int channelConfiguration = AudioFormat.CHANNEL_IN_STEREO;
    int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
    try {
      // 建立一個資料輸入流往檔案裡寫資料
      OutputStream os = new FileOutputStream(mFileName);
      BufferedOutputStream bos = new BufferedOutputStream(os);
      DataOutputStream dos = new DataOutputStream(bos);
      // 建立一個AudioRecord對象來錄音
      int bufferSize = AudioRecord.getMinBufferSize(frequency, channelConfiguration, audioEncoding);
      AudioRecord mAudioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency, channelConfiguration,
          audioEncoding, bufferSize);
      short[] buffer = new short[bufferSize];
      // 開始錄音
      mAudioRecord.startRecording();

      isRecording = true;
      Log.e(TAG, "record: 錄音開始");
      while (isRecording) {
        int bufferReadResult = mAudioRecord.read(buffer, 0, bufferSize);
        for (int i = 0; i < bufferReadResult; i++) {
          dos.writeShort(buffer[i]);
          Log.e(TAG, "record: 錄音中...");
        }
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * 停止錄音
   */
  class stopRecordListener implements OnClickListener {

    @Override public void onClick(View v) {
      mAudioRecord.stop();
      Log.e(TAG, "record: 錄音結束");
    }
  }
           

播放代碼：

/**
   * 播放錄音
   */
  class startPlayListener implements OnClickListener {

    @Override public void onClick(View v) {
      try {
        // Get the file we want to playback.
        File file = new File(mFileName);
        // Get the length of the audio stored in the file (16 bit so 2 bytes per short)
        // and create a short array to store the recorded audio.
        int musicLength = (int) (file.length() / 2);
        short[] music = new short[musicLength];
        // Create a DataInputStream to read the audio data back from the saved file
        InputStream is = new FileInputStream(file);
        BufferedInputStream bis = new BufferedInputStream(is);
        DataInputStream dis = new DataInputStream(bis);

        // Read the file into the music array.
        int i = 0;
        while (dis.available() > 0) {
          music[i++] = dis.readShort();
        }

        // close the input streams
        dis.close();

        // Create a new AudioTrack object using the same parameters as the AudioRecord
        // object used to create the file.
        AudioTrack audioTrack =
            new AudioTrack(AudioManager.STREAM_MUSIC, 11025, AudioFormat.CHANNEL_IN_STEREO,
                AudioFormat.ENCODING_PCM_16BIT, musicLength * 2, AudioTrack.MODE_STREAM);
        Log.e(TAG, "onClick: 開始播放");
        // Start playback
        audioTrack.play();

        // Write the music buffer to the AudioTrack object
        audioTrack.write(music, 0, musicLength);
        Log.e(TAG, "onClick: 播放結束");
        audioTrack.stop();
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  }