代码分析JAVA中PCM人声音频变声处理

项目中需要用到对PCM人声音频数据进行变声处理。苦苦挣扎了一周终于找到了纯Java实现的一套框架――TarsosDSP。功能非常强大！可以实时音频处理！当然我只用到了对文件处理。实际上逻辑是一样的

TarsosDSP的GitHub地址：https://github.com/JorenSix/TarsosDSP 将它整合至自己的项目工程。

具体Java工具类代码：

  /**
   * 变声
   * @param rawPcmInputStream 原始PCM数据输入流
   * @param speedFactor 变速率 (0,2) 大于1为加快语速，小于1为放慢语速
   * @param rateFactor 音调变化率 (0,2) 大于1为降低音调（深沉），小于1为提升音调（尖锐）
   * @return 变声后的PCM数据输入流
   */
  public static InputStream speechPitchShift(final InputStream rawPcmInputStream,double speedFactor,double rateFactor) {
    TarsosDSPAudioFormat format = new TarsosDSPAudioFormat(16000,16,1,true,false);
    AudioInputStream inputStream = new AudioInputStream(rawPcmInputStream, JVMAudioInputStream.toAudioFormat(format),AudioSystem.NOT_SPECIFIED);
    JVMAudioInputStream stream = new JVMAudioInputStream(inputStream);
    WaveformSimilarityBasedOverlapAdd w = new WaveformSimilarityBasedOverlapAdd(WaveformSimilarityBasedOverlapAdd.Parameters.speechDefaults(speedFactor, 16000));
    int inputBufferSize = w.getInputBufferSize();
    int overlap = w.getOverlap();
    AudioDispatcher dispatcher = new AudioDispatcher(stream, inputBufferSize ,overlap);
    w.setDispatcher(dispatcher);
    AudioOutputToByteArray out = new AudioOutputToByteArray();
    dispatcher.addAudioProcessor(w);
    dispatcher.addAudioProcessor(new RateTransposer(rateFactor));
    dispatcher.addAudioProcessor(out);
    dispatcher.run();
    return new ByteArrayInputStream(out.getData());
  }

其中数据转录器(AudioOutputToByteArray)代码如下：

public class AudioOutputToByteArray implements AudioProcessor {
  private boolean isDone = false;
  private byte[] out = null;
  private ByteArrayOutputStream bos;
  public AudioOutputToByteArray() {
    bos = new ByteArrayOutputStream();
  }
  public byte[] getData() {
    while (!isDone && out == null) {
      try {
        Thread.sleep(10);
      } catch (InterruptedException ignored) {}
    }
    return out;
  }
  @Override
  public boolean process(AudioEvent audioEvent) {
    bos.write(audioEvent.getByteBuffer(),0,audioEvent.getByteBuffer().length);
    return true;
  }
  @Override
  public void processingFinished() {
    out = bos.toByteArray().clone();
    bos = null;
    isDone = true;
  }
}

可以通过这个工具方法播放音频：

  /**
   * 播放PCM
   *
   * 不要在非桌面环境调用。。。鬼知道会发生什么
   * @param rawPcmInputStream 原始PCM数据输入流
   * @throws LineUnavailableException
   */
  public static void play(final InputStream rawPcmInputStream) throws LineUnavailableException {
    TarsosDSPAudioFormat format = new TarsosDSPAudioFormat(16000,16,1,true,false);
    AudioInputStream inputStream = new AudioInputStream(rawPcmInputStream, JVMAudioInputStream.toAudioFormat(format),AudioSystem.NOT_SPECIFIED);
    JVMAudioInputStream stream = new JVMAudioInputStream(inputStream);
    AudioDispatcher dispatcher = new AudioDispatcher(stream, 1024 ,0);
    dispatcher.addAudioProcessor(new AudioPlayer(format,1024));
    dispatcher.run();
  }