/*

  * Copyright (c) 2002-2014, Mairie de Paris

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  *

  *  1. Redistributions of source code must retain the above copyright notice

  *     and the following disclaimer.

  *

  *  2. Redistributions in binary form must reproduce the above copyright notice

  *     and the following disclaimer in the documentation and/or other materials

  *     provided with the distribution.

  *

  *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its

  *     contributors may be used to endorse or promote products derived from

  *     this software without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  *

  * License 1.0

  */

 package fr.paris.lutece.plugins.captcha.modules.jcaptcha.service.sound.filter;

 import java.io.FilterInputStream;

 import java.io.IOException;

 import javax.sound.sampled.AudioInputStream;

 /**

  * The FilteredSoundStream class is a FilterInputStream that applies a

  * SoundFilter to the underlying input stream.

  *

  * @see SoundFilter

  */

 public class FilteredSoundStream extends FilterInputStream

 {

     private static final int REMAINING_SIZE_UNKNOWN = -1;

     private SoundFilter _soundFilter;

     private int _remainingSize;

     private int _sampleSizeInBits;

     /**

      * Creates a new FilteredSoundStream object with the specified InputStream

      * and SoundFilter.

      *

      * @param in the file sound stream

      * @param soundFilter the sound filter

      */

     public FilteredSoundStream( AudioInputStream in, SoundFilter soundFilter )

     {

         super( in );

         _soundFilter = soundFilter;

         _remainingSize = REMAINING_SIZE_UNKNOWN;

         _sampleSizeInBits = in.getFormat(  ).getSampleSizeInBits(  );

     }

     /**

      * Overrides the FilterInputStream method to apply this filter whenever

      * bytes are read

      *

      * @param samples the samples

      * @param offset the offset

      * @param length the length of sample

      * @return the byte read

      * @throws IOException the IOException

      */

     public int read( byte[] samples, int offset, int length )

         throws IOException

     {

         int nLengthReturn = length;

         // read and filter the sound samples in the stream

         int bytesRead = super.read( samples, offset, nLengthReturn );

         if ( bytesRead > 0 )

         {

             _soundFilter.filter( samples, offset, bytesRead, _sampleSizeInBits );

             return bytesRead;

         }

         // if there are no remaining bytes in the sound stream,

         // check if the filter has any remaining bytes ("echoes").

         if ( _remainingSize == REMAINING_SIZE_UNKNOWN )

         {

             _remainingSize = _soundFilter.getRemainingSize(  );

             // round down to nearest multiple of 4

             // (typical frame size)

             _remainingSize = _remainingSize / 4 * 4;

         }

         if ( _remainingSize > 0 )

         {

             nLengthReturn = Math.min( nLengthReturn, _remainingSize );

             // clear the buffer

             for ( int i = offset; i < ( offset + nLengthReturn ); i++ )

             {

                 samples[i] = 0;

             }

             // filter the remaining bytes

             _soundFilter.filter( samples, offset, nLengthReturn, _sampleSizeInBits );

             _remainingSize -= nLengthReturn;

             return nLengthReturn;

         }

         else

         {

             // end of stream

             return -1;

         }

     }

 }