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();
  }