从原始文件中获取一些x字节的AudioInputStream(剪切音频文件)

Question

如何读取AudioInputStream特定数量的字节/微秒位置？例如 :

AudioInputStream ais = AudioSystem.getAudioInputStream( new File("file.wav") );
// let the file.wav be of y bytes

现在我想获得一个AudioInputStream具有高达某些x字节数据的数据x < y.

我怎样才能做到这一点 ？

我一直在努力思考但没有任何方法可以做到这一点？

Answer 1

下面的代码显示了如何复制音频流的一部分,从一个文件读取和写入另一个文件.

import java.io.*;
import javax.sound.sampled.*;

class AudioFileProcessor {

  public static void main(String[] args) {
    copyAudio("/tmp/uke.wav", "/tmp/uke-shortened.wav", 2, 1);
  }

  public static void copyAudio(String sourceFileName, String destinationFileName, int startSecond, int secondsToCopy) {
    AudioInputStream inputStream = null;
    AudioInputStream shortenedStream = null;
    try {
      File file = new File(sourceFileName);
      AudioFileFormat fileFormat = AudioSystem.getAudioFileFormat(file);
      AudioFormat format = fileFormat.getFormat();
      inputStream = AudioSystem.getAudioInputStream(file);
      int bytesPerSecond = format.getFrameSize() * (int)format.getFrameRate();
      inputStream.skip(startSecond * bytesPerSecond);
      long framesOfAudioToCopy = secondsToCopy * (int)format.getFrameRate();
      shortenedStream = new AudioInputStream(inputStream, format, framesOfAudioToCopy);
      File destinationFile = new File(destinationFileName);
      AudioSystem.write(shortenedStream, fileFormat.getType(), destinationFile);
    } catch (Exception e) {
      println(e);
    } finally {
      if (inputStream != null) try { inputStream.close(); } catch (Exception e) { println(e); }
      if (shortenedStream != null) try { shortenedStream.close(); } catch (Exception e) { println(e); }
    }
  }

  public static void println(Object o) {
    System.out.println(o);
  }

  public static void print(Object o) {
    System.out.print(o);
  }

}