package org.jaudiotagger.audio.flac;

 import org.jaudiotagger.audio.exceptions.CannotReadException;

 import java.io.RandomAccessFile;

 import java.io.IOException;

 /**

  * Flac Stream

  * <p/>

  * Identifies this is in fact a flac stream

  */

 public class FlacStream

 {

     public static final int FLAC_STREAM_IDENTIFIER_LENGTH = 4;

     public static final String FLAC_STREAM_IDENTIFIER = "fLaC";

     /**

      * Reads the stream block to ensure it is a flac file

      *

      * @param raf

      * @throws IOException

      * @throws CannotReadException

      */

     public static void findStream(RandomAccessFile raf) throws IOException, CannotReadException

     {

         //Begins tag parsing

         if (raf.length() == 0)

         {

             //Empty File

             throw new CannotReadException("Error: File empty");

         }

         raf.seek(0);

         //FLAC Stream

         byte[] b = new byte[FlacStream.FLAC_STREAM_IDENTIFIER_LENGTH];

         raf.read(b);

         String flac = new String(b);

         if (!flac.equals(FlacStream.FLAC_STREAM_IDENTIFIER))

         {

             throw new CannotReadException("fLaC Header not found, not a flac file");

         }

     }

 }