1 /*
2 * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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24 */
25
26 package javax.sound.sampled.spi;
27
28 import java.util.Arrays;
29
30 import javax.sound.sampled.AudioFormat;
31 import javax.sound.sampled.AudioInputStream;
32
33 import static javax.sound.sampled.AudioFormat.Encoding;
34
35 /**
36 * A format conversion provider provides format conversion services from one or
37 * more input formats to one or more output formats. Converters include codecs,
38 * which encode and/or decode audio data, as well as transcoders, etc. Format
39 * converters provide methods for determining what conversions are supported and
40 * for obtaining an audio stream from which converted data can be read.
41 * <p>
42 * The source format represents the format of the incoming audio data, which
43 * will be converted.
44 * <p>
45 * The target format represents the format of the processed, converted audio
46 * data. This is the format of the data that can be read from the stream
47 * returned by one of the {@code getAudioInputStream} methods.
48 *
49 * @author Kara Kytle
50 * @since 1.3
51 */
52 public abstract class FormatConversionProvider {
53
54 /**
55 * Constructs a {@code FormatConversionProvider}.
56 */
57 protected FormatConversionProvider() {}
58
59 /**
60 * Obtains the set of source format encodings from which format conversion
61 * services are provided by this provider.
62 *
63 * @return array of source format encodings. If for some reason provider
64 * does not provide any conversion services, an array of length 0 is
65 * returned.
66 */
67 public abstract Encoding[] getSourceEncodings();
68
69 /**
70 * Obtains the set of target format encodings to which format conversion
71 * services are provided by this provider.
72 *
73 * @return array of target format encodings. If for some reason provider
74 * does not provide any conversion services, an array of length 0 is
75 * returned.
76 */
77 public abstract Encoding[] getTargetEncodings();
78
79 /**
80 * Indicates whether the format converter supports conversion from the
81 * specified source format encoding.
82 *
83 * @param sourceEncoding the source format encoding for which support is
84 * queried
85 * @return {@code true} if the encoding is supported, otherwise
86 * {@code false}
87 * @throws NullPointerException if {@code sourceEncoding} is {@code null}
88 */
89 public boolean isSourceEncodingSupported(final Encoding sourceEncoding) {
90 return Arrays.stream(getSourceEncodings())
91 .anyMatch(sourceEncoding::equals);
92 }
93
94 /**
95 * Indicates whether the format converter supports conversion to the
96 * specified target format encoding.
97 *
98 * @param targetEncoding the target format encoding for which support is
99 * queried
100 * @return {@code true} if the encoding is supported, otherwise
101 * {@code false}
102 * @throws NullPointerException if {@code targetEncoding} is {@code null}
103 */
104 public boolean isTargetEncodingSupported(final Encoding targetEncoding) {
105 return Arrays.stream(getTargetEncodings())
106 .anyMatch(targetEncoding::equals);
107 }
108
109 /**
110 * Obtains the set of target format encodings supported by the format
111 * converter given a particular source format. If no target format encodings
112 * are supported for this source format, an array of length 0 is returned.
113 *
114 * @param sourceFormat format of the incoming data
115 * @return array of supported target format encodings
116 * @throws NullPointerException if {@code sourceFormat} is {@code null}
117 */
118 public abstract Encoding[] getTargetEncodings(AudioFormat sourceFormat);
119
120 /**
121 * Indicates whether the format converter supports conversion to a
122 * particular encoding from a particular format.
123 *
124 * @param targetEncoding desired encoding of the outgoing data
125 * @param sourceFormat format of the incoming data
126 * @return {@code true} if the conversion is supported, otherwise
127 * {@code false}
128 * @throws NullPointerException if {@code targetEncoding} or
129 * {@code sourceFormat} are {@code null}
130 */
131 public boolean isConversionSupported(final Encoding targetEncoding,
132 final AudioFormat sourceFormat) {
133 return Arrays.stream(getTargetEncodings(sourceFormat))
134 .anyMatch(targetEncoding::equals);
135 }
136
137 /**
138 * Obtains the set of target formats with the encoding specified supported
139 * by the format converter. If no target formats with the specified encoding
140 * are supported for this source format, an array of length 0 is returned.
141 *
142 * @param targetEncoding desired encoding of the stream after processing
143 * @param sourceFormat format of the incoming data
144 * @return array of supported target formats
145 * @throws NullPointerException if {@code targetEncoding} or
146 * {@code sourceFormat} are {@code null}
147 */
148 public abstract AudioFormat[] getTargetFormats(Encoding targetEncoding,
149 AudioFormat sourceFormat);
150
151 /**
152 * Indicates whether the format converter supports conversion to one
153 * particular format from another.
154 *
155 * @param targetFormat desired format of outgoing data
156 * @param sourceFormat format of the incoming data
157 * @return {@code true} if the conversion is supported, otherwise
158 * {@code false}
159 * @throws NullPointerException if {@code targetFormat} or
160 * {@code sourceFormat} are {@code null}
161 */
162 public boolean isConversionSupported(final AudioFormat targetFormat,
163 final AudioFormat sourceFormat) {
164 final Encoding targetEncoding = targetFormat.getEncoding();
165 return Arrays.stream(getTargetFormats(targetEncoding, sourceFormat))
166 .anyMatch(targetFormat::matches);
167 }
168
169 /**
170 * Obtains an audio input stream with the specified encoding from the given
171 * audio input stream.
172 *
173 * @param targetEncoding desired encoding of the stream after processing
174 * @param sourceStream stream from which data to be processed should be
175 * read
176 * @return stream from which processed data with the specified target
177 * encoding may be read
178 * @throws IllegalArgumentException if the format combination supplied is
179 * not supported
180 * @throws NullPointerException if {@code targetEncoding} or
181 * {@code sourceStream} are {@code null}
182 */
183 public abstract AudioInputStream getAudioInputStream(
184 Encoding targetEncoding, AudioInputStream sourceStream);
185
186 /**
187 * Obtains an audio input stream with the specified format from the given
188 * audio input stream.
189 *
190 * @param targetFormat desired data format of the stream after processing
191 * @param sourceStream stream from which data to be processed should be
192 * read
193 * @return stream from which processed data with the specified format may be
194 * read
195 * @throws IllegalArgumentException if the format combination supplied is
196 * not supported
197 * @throws NullPointerException if {@code targetFormat} or
198 * {@code sourceStream} are {@code null}
199 */
200 public abstract AudioInputStream getAudioInputStream(
201 AudioFormat targetFormat, AudioInputStream sourceStream);
202 }