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 java.io.FilterInputStream;
37 import java.io.IOException;
38
39 import javax.sound.sampled.AudioInputStream;
40
41 /**
42 * The FilteredSoundStream class is a FilterInputStream that applies a SoundFilter to the underlying input stream.
43 *
44 * @see SoundFilter
45 */
46 public class FilteredSoundStream extends FilterInputStream
47 {
48 private static final int REMAINING_SIZE_UNKNOWN = -1;
49 private SoundFilter _soundFilter;
50 private int _remainingSize;
51 private int _sampleSizeInBits;
52
53 /**
54 * Creates a new FilteredSoundStream object with the specified InputStream and SoundFilter.
55 *
56 * @param in
57 * the file sound stream
58 * @param soundFilter
59 * the sound filter
60 */
61 public FilteredSoundStream( AudioInputStream in, SoundFilter soundFilter )
62 {
63 super( in );
64 _soundFilter = soundFilter;
65 _remainingSize = REMAINING_SIZE_UNKNOWN;
66 _sampleSizeInBits = in.getFormat( ).getSampleSizeInBits( );
67 }
68
69 /**
70 * Overrides the FilterInputStream method to apply this filter whenever bytes are read
71 *
72 * @param samples
73 * the samples
74 * @param offset
75 * the offset
76 * @param length
77 * the length of sample
78 * @return the byte read
79 * @throws IOException
80 * the IOException
81 */
82 public int read( byte [ ] samples, int offset, int length ) throws IOException
83 {
84 int nLengthReturn = length;
85
86 // read and filter the sound samples in the stream
87 int bytesRead = super.read( samples, offset, nLengthReturn );
88
89 if ( bytesRead > 0 )
90 {
91 _soundFilter.filter( samples, offset, bytesRead, _sampleSizeInBits );
92
93 return bytesRead;
94 }
95
96 // if there are no remaining bytes in the sound stream,
97 // check if the filter has any remaining bytes ("echoes").
98 if ( _remainingSize == REMAINING_SIZE_UNKNOWN )
99 {
100 _remainingSize = _soundFilter.getRemainingSize( );
101 // round down to nearest multiple of 4
102 // (typical frame size)
103 _remainingSize = _remainingSize / 4 * 4;
104 }
105
106 if ( _remainingSize > 0 )
107 {
108 nLengthReturn = Math.min( nLengthReturn, _remainingSize );
109
110 // clear the buffer
111 for ( int i = offset; i < ( offset + nLengthReturn ); i++ )
112 {
113 samples [i] = 0;
114 }
115
116 // filter the remaining bytes
117 _soundFilter.filter( samples, offset, nLengthReturn, _sampleSizeInBits );
118 _remainingSize -= nLengthReturn;
119
120 return nLengthReturn;
121 }
122 else
123 {
124 // end of stream
125 return -1;
126 }
127 }
128 }