// read_wav.java     read_wav  ok.wav
//                         reads bytes one at a time as an int

import java.io.*;

public class read_wav
{
  char riff[] = new char[4];
  int  sread, swrite;
  int  fsize;
  char wave[] = new char[4];
  char fmt[] = new char[4];
  int  nbytes;
  short  ccode;
  short  channels;
  int rate;
  int avgrate;
  short blockalign;
  short bps; // bits per sample 
  char data[] = new char[4];
  int csize[] = new int[50]; // max 50 chunks
  int ncsize = 0; 
  int ibyte; // byte of cound
  char more[] = new char[4];
  int smin = 0;
  int smax = 0;
  int savg;
  int nbread; // number of bytes read 
  int outix;  // number of output samples
  int A[];    // output sound amplitude, bigger than outix

    public read_wav(String file_in, String file_out, boolean ifwrite)
  {
    wav_read(file_in);
    if(ifwrite) wav_write(file_out);
  }

  void wav_read(String inp)
  {
    System.out.println("read_wav running,  reading "+inp);
    outix = 0;

    try
    {
      FileInputStream ds = new FileInputStream(inp);

      sread = 4;
      for(int i=0; i<sread; i++) riff[i] = (char)ds.read();
      System.out.println("read "+sread+" bytes, should be 4");
      System.out.println("first 4 bytes should be RIFF "+
                         riff[0]+riff[1]+riff[2]+riff[3]);

      fsize = 0;
      smax = 1;
      for(int i=0; i<4; i++) { fsize += ds.read()*smax; smax *= 256;}
      System.out.println("file has "+fsize+" +8 bytes");

      for(int i=0; i<4; i++) wave[i] = (char)ds.read();
      System.out.println("4 bytes should be WAVE "+
                         wave[0]+wave[1]+wave[2]+wave[3]);

      for(int i=0; i<4; i++) fmt[i] = (char)ds.read();
      System.out.println("4 bytes should be fmt  "+
                         fmt[0]+fmt[1]+fmt[2]+fmt[3]);

      nbytes = 0;
      smax = 1;
      for(int i=0; i<4; i++) { nbytes += ds.read()*smax; smax *= 256;}
      System.out.println("block has "+nbytes+" bytes");

      ccode = 0;
      smax = 1;
      for(int i=0; i<2; i++) { ccode += ds.read()*smax; smax *= 256;}
      System.out.println("compression code = "+ccode);

      channels = 0;
      smax = 1;
      for(int i=0; i<2; i++) { channels += ds.read()*smax; smax *= 256;}
      System.out.println("channels = "+channels);

      rate = 0;
      smax = 1;
      for(int i=0; i<4; i++) { rate += ds.read()*smax; smax *= 256;}
      System.out.println("rate = "+rate);

      avgrate = 0;
      smax = 1;
      for(int i=0; i<4; i++) { avgrate += ds.read()*smax; smax *= 256;}
      System.out.println("avg rate = "+avgrate);

      blockalign = 0;
      smax = 1;
      for(int i=0; i<2; i++) { blockalign += ds.read()*smax; smax *= 256;}
      System.out.println("blockalign = "+blockalign);

      bps = 0;
      smax = 1;
      for(int i=0; i<2; i++) { bps += ds.read()*smax; smax *= 256;}
      System.out.println("bits per sample = "+bps);

      for(int i=0; i<4; i++) data[i] = (char)ds.read();
      System.out.println("4 bytes should be data "+
                         data[0]+data[1]+data[2]+data[3]);

      csize[ncsize] = 0;
      smax = 1;
      for(int i=0; i<4; i++) { csize[ncsize] += ds.read()*smax; smax *= 256;}
      System.out.println("chunk has "+csize[ncsize]+" bytes");

      nbread = 44;
      System.out.println(nbread+" bytes read so far");
      A = new int[fsize+8-nbread]; // -8 +8 below thus big enough
      outix = 0;

      savg = 0;
      for(int i=0; i<csize[ncsize]; i++)
      {
	ibyte = ds.read(); // signed byte
        if(ibyte>127) ibyte = ibyte-256;
        A[outix] = ibyte;
        outix++;
        savg = savg + ibyte;
        if(i==0) {smin=ibyte; smax=ibyte;}
        smin = ibyte<smin?ibyte:smin;
        smax = ibyte>smax?ibyte:smax;
        if(i<10 || i>csize[ncsize]-10)
           System.out.println("sound byte ="+ibyte);
      }
      savg = savg / csize[ncsize];
      System.out.println("smin="+smin+", smax="+smax+", savg="+savg);

      nbread = nbread+csize[ncsize];
      System.out.println(nbread+" bytes read so far");
      
      // read rest of chunks
      while(nbread+17<fsize)
      {
	ncsize++;
        for(int i=0; i<4; i++) more[i] = (char)ds.read();
        System.out.println("4 bytes should be WAVE "+
                           more[0]+more[1]+more[2]+more[3]);

        csize[ncsize] = 0;
        smax = 1;
        for(int i=0; i<4; i++) { csize[ncsize] += ds.read()*smax; smax *= 256;}
        System.out.println("chunk has "+csize[ncsize]+" bytes");

        for(int i=0; i<csize[ncsize]; i++)
        {
	  ibyte = ds.read(); // signed byte
          if(ibyte>127) ibyte = ibyte-256;
          A[outix] = ibyte;
          outix++;
	}
        nbread = nbread+8+csize[ncsize];
        System.out.println(nbread+" bytes read so far");
      }
      ds.close();
    }
    catch(Exception e)
    {
      System.out.println("wav_read, some exception thrown");
    }
    System.out.println("end wav_read");
  } // end wav_read 


  void wav_write(String outp)
  {
    System.out.println("read_write running,  writing "+outp);
    int inix = 0;

    ncsize=0;
    try
    {
      FileOutputStream ds = new FileOutputStream(outp);

      sread = 4;
      for(int i=0; i<sread; i++) ds.write(riff[i]);
      System.out.println("wrote "+sread+" bytes, should be 4");
      System.out.println("wrote first 4 bytes should be RIFF "+
                         riff[0]+riff[1]+riff[2]+riff[3]);

      smax = fsize;
      for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote file has "+fsize+" +8 bytes");

      for(int i=0; i<4; i++) ds.write(wave[i]);
      System.out.println("wrote 4 bytes should be WAVE "+
                         wave[0]+wave[1]+wave[2]+wave[3]);

      for(int i=0; i<4; i++) ds.write(fmt[i]);
      System.out.println("wrote 4 bytes should be fmt  "+
                         fmt[0]+fmt[1]+fmt[2]+fmt[3]);

      smax = nbytes;
      for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote block has "+nbytes+" bytes");

      smax = ccode;
      for(int i=0; i<2; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote compression code = "+ccode);

      smax = channels;
      for(int i=0; i<2; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote channels = "+channels);

      smax = rate;
      for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote rate = "+rate);

      smax = avgrate;
      for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote avg rate = "+avgrate);

      
      smax = blockalign;
      for(int i=0; i<2; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote blockalign = "+blockalign);

      
      smax = bps;
      for(int i=0; i<2; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote bits per sample = "+bps);

      for(int i=0; i<4; i++) ds.write(data[i]);
      System.out.println("wrote 4 bytes should be data "+
                         data[0]+data[1]+data[2]+data[3]);

      smax = csize[ncsize];
      for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
      System.out.println("wrote chunk has "+csize[ncsize]+" bytes");

      nbread = 44;
      System.out.println(nbread+" bytes written so far");

      savg = 0;
      for(int i=0; i<csize[ncsize]; i++)
      {
	ibyte = A[inix];
        inix++;
        if(ibyte<0) ibyte = ibyte+256;
	ds.write(ibyte); // signed byte
        if(inix>=outix) break;
      }

      nbread = nbread+csize[ncsize];
      System.out.println(nbread+" bytes written so far");

      // write rest of chunks
      while(nbread+17<fsize)
      {
	ncsize++;
        if(inix>=outix) break;
        for(int i=0; i<4; i++) ds.write(more[i]);
        System.out.println("wrote 4 bytes should be WAVE "+
                           more[0]+more[1]+more[2]+more[3]);

        smax = csize[ncsize];
        for(int i=0; i<4; i++) { ds.write(smax%256); smax /= 256;}
        System.out.println("wrote chunk has "+csize[ncsize]+" bytes");

        for(int i=0; i<csize[ncsize]; i++)
        {
	  ibyte = A[inix];
          inix++;
          if(ibyte<0) ibyte = ibyte+256;
	  ds.write(ibyte); // signed byte
          if(inix>=outix) break;
	}
        nbread = nbread+8+csize[ncsize];
        System.out.println(nbread+" bytes written so far");
      }
      // ds.write(0);  // on some files
      ds.close();
    }
    catch(Exception e)
    {
      System.out.println("wav_write, some exception thrown");
    }
    System.out.println("end wav_write");
  } // end wav_write

  public static void main (String[] args)
  {
    String file_in = "ok.wav";
    if(args.length>0)
    {
      file_in = args[0];
    }
    String file_out = "junk.wav";
    if(args.length>1)
    {
      file_out = args[1];
    }
    new read_wav(file_in, file_out, true);
  } // end main
} // end class read_wav of read_wav.java