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1   /*
2    * Copyright (c) 2002-2021, City of Paris
3    * All rights reserved.
4    *
5    * Redistribution and use in source and binary forms, with or without
6    * modification, are permitted provided that the following conditions
7    * are met:
8    *
9    *  1. Redistributions of source code must retain the above copyright notice
10   *     and the following disclaimer.
11   *
12   *  2. Redistributions in binary form must reproduce the above copyright notice
13   *     and the following disclaimer in the documentation and/or other materials
14   *     provided with the distribution.
15   *
16   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
17   *     contributors may be used to endorse or promote products derived from
18   *     this software without specific prior written permission.
19   *
20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30   * POSSIBILITY OF SUCH DAMAGE.
31   *
32   * License 1.0
33   */
34  package fr.paris.lutece.plugins.captcha.modules.jcaptcha.service.sound.filter;
35  
36  import javax.sound.sampled.AudioFormat;
37  import javax.sound.sampled.AudioFormat.Encoding;
38  import javax.sound.sampled.AudioInputStream;
39  
40  /**
41   *
42   */
43  public class PitchFilter extends SoundFilter
44  {
45      private float _pitchMinValue;
46      private float _pitchMaxValue;
47  
48      /**
49       * Creates an PitchFilter with the specified minimum and maximum relative original sound pitch (in percent)
50       * <p>
51       * 
52       * @param pitchMinValue
53       *            the pitch Min Value
54       * @param pitchMaxValue
55       *            the pitch Max Value
56       */
57      public PitchFilter( float pitchMinValue, float pitchMaxValue )
58      {
59          _pitchMinValue = pitchMinValue / 100f;
60          this._pitchMaxValue = pitchMaxValue / 100f;
61      }
62  
63      /**
64       * Filter do nothing, only AudioFormat was modified
65       *
66       * @param samples
67       *            the samples
68       * @param offset
69       *            the offset
70       * @param length
71       *            the length
72       * @param sampleSizeInBits
73       *            the sample size in bits
74       */
75      public void filter( byte [ ] samples, int offset, int length, int sampleSizeInBits )
76      {
77          // Do nothing
78      }
79  
80      /**
81       * Apply coefficient to the original audio input format pitch
82       *
83       * @param audioInputStream
84       *            the audio input stream
85       * @return the audio format
86       */
87      public AudioFormat getAudioFormat( AudioInputStream audioInputStream )
88      {
89          AudioFormat originalFormat = audioInputStream.getFormat( );
90          float coef = (float) ( Math.random( ) * ( _pitchMaxValue - _pitchMinValue ) ) + _pitchMinValue;
91          float messagePitchRate = originalFormat.getFrameRate( ) * coef;
92  
93          return new AudioFormat( messagePitchRate, originalFormat.getSampleSizeInBits( ), originalFormat.getChannels( ),
94                  originalFormat.getEncoding( ).equals( Encoding.PCM_SIGNED ), originalFormat.isBigEndian( ) );
95      }
96  
97      /**
98       *
99       * @return the pitch min value
100      */
101     public float getPitchMinValue( )
102     {
103         return _pitchMinValue;
104     }
105 
106     /**
107      * ste the pitch min value
108      *
109      * @param pitchMinValue
110      *            the pitch min value
111      */
112     public void setPitchMinValue( float pitchMinValue )
113     {
114         _pitchMinValue = pitchMinValue;
115     }
116 
117     /**
118      *
119      * @return the pitch max value
120      */
121     public float getPitchMaxValue( )
122     {
123         return _pitchMaxValue;
124     }
125 
126     /**
127      * set the pitch max value
128      *
129      * @param pitchMaxValue
130      *            the pitch max value
131      */
132     public void setPitchMaxValue( float pitchMaxValue )
133     {
134         this._pitchMaxValue = pitchMaxValue;
135     }
136 }