Android：需要录制麦克风输入

2 回答

• 10

  要（几乎）实时录制和播放音频，您可以启动一个单独的线程并使用 AudioRecord 和 AudioTrack .

  请小心反馈 . 如果您的设备上的扬声器声音很大，那么反馈可能非常快 .

  /*
   * Thread to manage live recording/playback of voice input from the device's microphone.
   */
  private class Audio extends Thread
  { 
      private boolean stopped = false;
  
      /**
       * Give the thread high priority so that it's not canceled unexpectedly, and start it
       */
      private Audio()
      { 
          android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
          start();
      }
  
      @Override
      public void run()
      { 
          Log.i("Audio", "Running Audio Thread");
          AudioRecord recorder = null;
          AudioTrack track = null;
          short[][]   buffers  = new short[256][160];
          int ix = 0;
  
          /*
           * Initialize buffer to hold continuously recorded audio data, start recording, and start
           * playback.
           */
          try
          {
              int N = AudioRecord.getMinBufferSize(8000,AudioFormat.CHANNEL_IN_MONO,AudioFormat.ENCODING_PCM_16BIT);
              recorder = new AudioRecord(AudioSource.MIC, 8000, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, N*10);
              track = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, 
                      AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, N*10, AudioTrack.MODE_STREAM);
              recorder.startRecording();
              track.play();
              /*
               * Loops until something outside of this thread stops it.
               * Reads the data from the recorder and writes it to the audio track for playback.
               */
              while(!stopped)
              { 
                  Log.i("Map", "Writing new data to buffer");
                  short[] buffer = buffers[ix++ % buffers.length];
                  N = recorder.read(buffer,0,buffer.length);
                  track.write(buffer, 0, buffer.length);
              }
          }
          catch(Throwable x)
          { 
              Log.w("Audio", "Error reading voice audio", x);
          }
          /*
           * Frees the thread's resources after the loop completes so that it can be run again
           */
          finally
          { 
              recorder.stop();
              recorder.release();
              track.stop();
              track.release();
          }
      }
  
      /**
       * Called from outside of the thread in order to stop the recording/playback loop
       */
      private void close()
      { 
           stopped = true;
      }
  
  }
  

  EDIT

  音频并没有真正录制到文件中 . AudioRecord 对象将音频编码为16 bit PCM data并将其放在缓冲区中 . 然后 AudioTrack 对象从该缓冲区读取数据并通过扬声器播放 . SD卡上没有您以后可以访问的文件 .

  您无法同时从SD卡读取和写入文件以实时进行播放/预览，因此您必须使用缓冲区 .

  回复于 2024-05-02T09:44:49+08:00
• 62

  清单中的以下权限需要正常工作：

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

  此外，不需要2d缓冲区阵列 . 即使只有一个缓冲区，代码的逻辑也是有效的，如下所示：

  short[] buffer = new short[160];
  while (!stopped) {
      //Log.i("Map", "Writing new data to buffer");
      int n = recorder.read(buffer, 0, buffer.length);
      track.write(buffer, 0, n);
  }
  

  回复于 2024-05-02T09:44:49+08:00