import it.sauronsoftware.jave.Encoder;
import it.sauronsoftware.jave.EncoderException;
import it.sauronsoftware.jave.MultimediaInfo;


import java.io.*;
import java.nio.ByteBuffer;

/**
 * FileName: WavCut
 * Author:   xuan zongjun
 * Date:     2018/10/18 10:45
 * Description: wav視訊切割
 */


public class WavCut {
    /**
     * @param sourcefile
     * @param targetfile
     * @param start
     * @param end
     * @return
     */
    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;  //音訊資料大小（44為128kbps位元率wav檔案頭長度）
            long splitSize = (wavSize / t1) * (end - start);  //擷取的音訊資料大小
            long skipSize = (wavSize / t1) * start;  //擷取時跳過的音訊資料大小
            int splitSizeInt = Integer.parseInt( String.valueOf( splitSize ) );
            int skipSizeInt = Integer.parseInt( String.valueOf( skipSize ) );

            ByteBuffer buf1 = ByteBuffer.allocate( 4 );  //存放檔案大小,4代表一個int佔用位元組數
            buf1.putInt( splitSizeInt + 36 );  //放入檔案長度資訊
            byte[] flen = buf1.array();  //代表檔案長度
            ByteBuffer buf2 = ByteBuffer.allocate( 4 );  //存放音訊資料大小，4代表一個int佔用位元組數
            buf2.putInt( splitSizeInt );  //放入資料長度資訊
            byte[] dlen = buf2.array();  //代表資料長度
            flen = reverse( flen );  //陣列反轉
            dlen = reverse( dlen );
            byte[] head = new byte[44];  //定義wav頭部資訊陣列
            fis.read( head, 0, head.length );  //讀取源wav檔案頭部資訊
            for (int i = 0; i < 4; i++) {  //4代表一個int佔用位元組數
                head[i + 4] = flen[i];  //替換原頭部資訊裡的檔案長度
                head[i + 40] = dlen[i];  //替換原頭部資訊裡的資料長度
            }
            byte[] fbyte = new byte[splitSizeInt + head.length];  //存放擷取的音訊資料
            for (int i = 0; i < head.length; i++) {  //放入修改後的頭部資訊
                fbyte[i] = head[i];
            }
            byte[] skipBytes = new byte[skipSizeInt];  //存放擷取時跳過的音訊資料
            fis.read( skipBytes, 0, skipBytes.length );  //跳過不需要擷取的資料
            fis.read( fbyte, head.length, fbyte.length - head.length );  //讀取要擷取的資料到目標陣列
            fis.close();

            File target = new File( targetfile );
            if (target.exists()) {  //如果目標檔案已存在，則刪除目標檔案
                target.delete();
            }
            FileOutputStream fos = new FileOutputStream( target );
            fos.write( fbyte );
            fos.flush();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
        return true;
    }


    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;
    }

    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) {
    String fileName ="D:\\wav\\pcmpcmpcm.wav";
    String targetName1 ="D:\\wav2\\pcmpcmpcm1.wav";
    String targetName2 ="D:\\wav2\\pcmpcmpcm2.wav";

    boolean result1 =  cut(fileName,targetName1,0,5);
    boolean result3 = cut(fileName,targetName2,5,9);
    System.out.println(result1);
    System.out.println(result3);
}

}