/* riffread class reads existing RIFF format file and determines 
      (1) if valid RIFF file
      (2) chunk structure
      (3) details of fmt chunk
                           by M. Gallant   2/14/97        */


import java.io.* ;
import java.awt.* ;
import java.util.Date ;
public class riffread {

 public static void main(String args[]) throws IOException {
   String nl = System.getProperty("line.separator") ;
   String fileSeparator = System.getProperty("file.separator") ;
  String selectFileDir ;
  String selectFile;
  FileInputStream fis = null ;
  FileOutputStream fos = null ;
 
     Frame myFrame = new Frame("Parent Frame") ;
     FileDialog myFD; 
       myFrame.resize(200,200) ;
       //myFrame.show() ;
       myFrame.hide() ;

  myFD= new FileDialog(myFrame, "Open a Text File") ;
  myFD.show() ;    // this blocks main program thread until select.

   //System.out.println("Chosen File"  +myFD.getFile() );
   //System.out.println("Chosen Directory" +myFD.getDirectory() ) ;

  selectFileDir = myFD.getDirectory() ;  // determine is file directory ends properly.
   if( selectFileDir.charAt(selectFileDir.length()-1) != fileSeparator.charAt(0)) 
         selectFileDir += fileSeparator ;

  selectFile = selectFileDir + myFD.getFile() ;
  //System.out.println("Input File Location  " + selectFile) ;

  try {fis = new  FileInputStream(selectFile); }
   catch (IOException ie) { }


 DataInputStream dis = new DataInputStream(fis) ;
 

try {  

  int riffdata=0;  // size of RIFF data chunk.
  int chunkSize=0, bytecount=0;
  String sfield="" ;
  String sp = "     " ;  // spacer string.
  String indent = sp + "     " ;
long filesize = (new File(selectFile)).length() ;  // get file length.
System.out.println(" ******  FILE:  " + selectFile   + "    LENGTH:  " + filesize + " bytes ****** \n") ; 

/*  --------  Get RIFF chunk header --------- */
  for (int i=1; i<=4; i++) 
     sfield+=(char)dis.readByte() ;
   if (!sfield.equals("RIFF")) {
     System.out.println(" ****  Not a valid RIFF file  ****") ;
     return ;
    }      

  for (int i=0; i<4; i++) 
    chunkSize += dis.readUnsignedByte() *(int)Math.pow(256,i) ;
  System.out.println(sp+sfield + "    ----- data size: "+chunkSize+ " bytes") ;
   
sfield="" ;
  for (int i=1; i<=4; i++) 
     sfield+=(char)dis.readByte() ;
 System.out.println(sp+"        ----- form type: "+ sfield + "\n") ;

  riffdata=chunkSize ;
/* --------------------------------------------- */

   bytecount = 4 ;  // initialize bytecount to include RIFF form-type bytes.

  while (bytecount < riffdata )  {    // check for chunks inside RIFF data area. 
      sfield="" ;
          for (int i=1; i<=4; i++) 
            sfield+=(char)dis.readByte() ;

     chunkSize=0 ;
         for (int i=0; i<4; i++) 
           chunkSize += dis.readUnsignedByte() *(int)Math.pow(256,i) ;
      bytecount += (8+chunkSize) ;
     System.out.println("\n" +sp+ sfield + "    ----- data size: "+chunkSize+ " bytes") ;

    if (sfield.equals("fmt ")) {               // extract info from "format" chunk.
         if (chunkSize<16) {
             System.out.println(" ****  Not a valid fmt chunk  ****") ;
             return ;
           }      
       int wFormatTag = dis.readUnsignedByte() ;
         dis.skipBytes(1) ;  
            if (wFormatTag == 1) 
              System.out.println(indent + "wFormatTag:  MS PCM format") ;
            else
              System.out.println(indent + "wFormatTag:  non-PCM format") ;
       int nChannels = dis.readUnsignedByte() ;
           dis.skipBytes(1) ;
             System.out.println(indent + "nChannels:  "+nChannels) ;
       int nSamplesPerSec=0 ;
         for (int i=0; i<4; i++) 
           nSamplesPerSec += dis.readUnsignedByte() *(int)Math.pow(256,i) ;
             System.out.println(indent + "nSamplesPerSec:  "+nSamplesPerSec) ;
       int nAvgBytesPerSec=0 ;
         for (int i=0; i<4; i++) 
           nAvgBytesPerSec += dis.readUnsignedByte() *(int)Math.pow(256,i) ;
             System.out.println(indent + "nAvgBytesPerSec:  "+nAvgBytesPerSec) ;
       int nBlockAlign=0;
         for (int i=0; i<2; i++)
           nBlockAlign += dis.readUnsignedByte() *(int)Math.pow(256,i) ;
             System.out.println(indent + "nBlockAlign:  "+nBlockAlign) ;
          if (wFormatTag ==1) {     // if MS PCM format
             int nBitsPerSample = dis.readUnsignedByte() ;
             dis.skipBytes(1) ;
             System.out.println(indent + "nBitsPerSample:  "+nBitsPerSample) ;
            }
           else  dis.skipBytes(2) ;
          dis.skipBytes(chunkSize-16) ; //skip over any extra bytes in format specific field.                                  
      }
     else    // if NOT the fmt chunk.
   dis.skipBytes(chunkSize) ;

  }  // end while.

    System.out.println("\n"+sp+"Final RIFF data bytecount: " + bytecount) ;
     if ((8+bytecount) != (int)filesize) 
        System.out.println(sp+"!!!!!!! Problem with file structure  !!!!!!!!! ") ; 
      else 
        System.out.println(sp+"File chunk structure consistent with valid RIFF ") ; 
     System.out.println(" -------------------------------------------------------") ;   
 }  // end try.


 finally {
         myFrame.dispose() ;
         dis.close() ;                         // close all streams.
         fis.close() ;
       }
 }



}