import it.sauronsoftware.jave.Encoder;
import it.sauronsoftware.jave.MultimediaInfo;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
/**
 * wav音頻文件截取工具
 * （適用于比特率為128kbps的wav音頻文件，此類音頻文件的頭部信息占用長度44字節(jié)）
 * @author lwj
 *
 */
public class WavCut {
  /**
   * 截取wav音頻文件
   * @param sourcepath 源文件地址
   * @param targetpath 目標文件地址
   * @param start 截取開始時間（秒）
   * @param end 截取結(jié)束時間（秒）
   *
   * return 截取成功返回true，否則返回false
   */
  public static boolean cut(String sourcefile, String targetfile, int start, int end) {
    try{
      if(!sourcefile.toLowerCase().endsWith(".wav") || !targetfile.toLowerCase().endsWith(".wav")){
        return false;
      }
      File wav = new File(sourcefile);
      if(!wav.exists()){
        return false;
      }
      long t1 = getTimeLen(wav); //總時長(秒)
      if(start<0 || end<=0 || start>=t1 || end>t1 || start>=end){
        return false;
      }
      FileInputStream fis = new FileInputStream(wav);
      long wavSize = wav.length()-44; //音頻數(shù)據(jù)大小（44為128kbps比特率wav文件頭長度）
      long splitSize = (wavSize/t1)*(end-start); //截取的音頻數(shù)據(jù)大小
      long skipSize = (wavSize/t1)*start; //截取時跳過的音頻數(shù)據(jù)大小
      int splitSizeInt = Integer.parseInt(String.valueOf(splitSize));
      int skipSizeInt = Integer.parseInt(String.valueOf(skipSize));
      ByteBuffer buf1 = ByteBuffer.allocate(4); //存放文件大小,4代表一個int占用字節(jié)數(shù)
      buf1.putInt(splitSizeInt+36); //放入文件長度信息
      byte[] flen = buf1.array(); //代表文件長度
      ByteBuffer buf2 = ByteBuffer.allocate(4); //存放音頻數(shù)據(jù)大小，4代表一個int占用字節(jié)數(shù)
      buf2.putInt(splitSizeInt); //放入數(shù)據(jù)長度信息
      byte[] dlen = buf2.array(); //代表數(shù)據(jù)長度
      flen = reverse(flen); //數(shù)組反轉(zhuǎn)
      dlen = reverse(dlen);
      byte[] head = new byte[44]; //定義wav頭部信息數(shù)組
      fis.read(head, 0, head.length); //讀取源wav文件頭部信息
      for(int i=0; i<4; i++){ //4代表一個int占用字節(jié)數(shù)
        head[i+4] = flen[i]; //替換原頭部信息里的文件長度
        head[i+40] = dlen[i]; //替換原頭部信息里的數(shù)據(jù)長度
      }
      byte[] fbyte = new byte[splitSizeInt+head.length]; //存放截取的音頻數(shù)據(jù)
      for(int i=0; i<head.length; i++){ //放入修改后的頭部信息
        fbyte[i] = head[i];
      }
      byte[] skipBytes = new byte[skipSizeInt]; //存放截取時跳過的音頻數(shù)據(jù)
      fis.read(skipBytes, 0, skipBytes.length); //跳過不需要截取的數(shù)據(jù)
      fis.read(fbyte, head.length, fbyte.length-head.length); //讀取要截取的數(shù)據(jù)到目標數(shù)組
      fis.close();
      File target = new File(targetfile);
      if(target.exists()){ //如果目標文件已存在，則刪除目標文件
        target.delete();
      }
      FileOutputStream fos = new FileOutputStream(target);
      fos.write(fbyte);
      fos.flush();
      fos.close();
    }catch(IOException e){
      e.printStackTrace();
      return false;
    }
    return true;
  }
  /**
   * 獲取音頻文件總時長
   * @param filePath 文件路徑
   * @return
   */
  public static long getTimeLen(File file){
    long tlen = 0;
    if(file!=null && file.exists()){
      Encoder encoder = new Encoder();
      try {
         MultimediaInfo m = encoder.getInfo(file);
         long ls = m.getDuration();
         tlen = ls/1000;
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
    return tlen;
  }
  /**
  * 數(shù)組反轉(zhuǎn)
  * @param array
  */
  public static byte[] reverse(byte[] array){
    byte temp;
    int len=array.length;
    for(int i=0;i<len/2;i++){
      temp=array[i];
      array[i]=array[len-1-i];
      array[len-1-i]=temp;
    }
    return array;
  }
  public static void main(String[] args){
    System.out.println(cut("f:\\111.wav","f:\\111-cut_0_10.wav",0,10));
    System.out.println(cut("f:\\111.wav","f:\\111-cut_10_20.wav",10,20));
    System.out.println(cut("f:\\111.wav","f:\\111-cut_20_28.wav",20,28));
  }
}

/**
 * wave文件頭信息
 * @author lwj
 *
 */
public class Head {
  public int riff_id;      //4 byte , 'RIFF'
  public int file_size;     //4 byte , 文件長度（數(shù)據(jù)長度+36）
  public int riff_type;     //4 byte , 'WAVE'
  public int fmt_id;      //4 byte , 'fmt'
  public int fmt_size;     //4 byte , 數(shù)值為16或18，18則最后又附加信息
  public short fmt_tag;     //2 byte , 編碼方式，一般為0x0001
  public short fmt_channel;   //2 byte , 聲道數(shù)目，1--單聲道；2--雙聲道
  public int fmt_samplesPerSec;//4 byte , 采樣頻率
  public int avgBytesPerSec;  //4 byte , 每秒所需字節(jié)數(shù),記錄每秒的數(shù)據(jù)量
  public short blockAlign;   //2 byte , 數(shù)據(jù)塊對齊單位(每個采樣需要的字節(jié)數(shù))
  public short bitsPerSample;  //2 byte , 每個采樣需要的bit數(shù)
  public int data_id;      //4 byte , 字符data
  public int data_size;     //4 byte , 數(shù)據(jù)長度
  public int getRiff_id() {
    return riff_id;
  }
  public void setRiff_id(int riff_id) {
    this.riff_id = riff_id;
  }
  public int getFile_size() {
    return file_size;
  }
  public void setFile_size(int file_size) {
    this.file_size = file_size;
  }
  public int getRiff_type() {
    return riff_type;
  }
  public void setRiff_type(int riff_type) {
    this.riff_type = riff_type;
  }
  public int getFmt_id() {
    return fmt_id;
  }
  public void setFmt_id(int fmt_id) {
    this.fmt_id = fmt_id;
  }
  public int getFmt_size() {
    return fmt_size;
  }
  public void setFmt_size(int fmt_size) {
    this.fmt_size = fmt_size;
  }
  public short getFmt_tag() {
    return fmt_tag;
  }
  public void setFmt_tag(short fmt_tag) {
    this.fmt_tag = fmt_tag;
  }
  public short getFmt_channel() {
    return fmt_channel;
  }
  public void setFmt_channel(short fmt_channel) {
    this.fmt_channel = fmt_channel;
  }
  public int getFmt_samplesPerSec() {
    return fmt_samplesPerSec;
  }
  public void setFmt_samplesPerSec(int fmt_samplesPerSec) {
    this.fmt_samplesPerSec = fmt_samplesPerSec;
  }
  public int getAvgBytesPerSec() {
    return avgBytesPerSec;
  }
  public void setAvgBytesPerSec(int avgBytesPerSec) {
    this.avgBytesPerSec = avgBytesPerSec;
  }
  public short getBlockAlign() {
    return blockAlign;
  }
  public void setBlockAlign(short blockAlign) {
    this.blockAlign = blockAlign;
  }
  public short getBitsPerSample() {
    return bitsPerSample;
  }
  public void setBitsPerSample(short bitsPerSample) {
    this.bitsPerSample = bitsPerSample;
  }
  public int getData_id() {
    return data_id;
  }
  public void setData_id(int data_id) {
    this.data_id = data_id;
  }
  public int getData_size() {
    return data_size;
  }
  public void setData_size(int data_size) {
    this.data_size = data_size;
  }
}