1 /* libFLAC - Free Lossless Audio Codec library
2 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006 Josh Coalson
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
8 * - Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * - Neither the name of the Xiph.org Foundation nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
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24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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42 #include "stream_decoder.h"
43 #include "stream_encoder.h"
47 * \section intro Introduction
49 * This is the documentation for the FLAC C and C++ APIs. It is
50 * highly interconnected; this introduction should give you a top
51 * level idea of the structure and how to find the information you
52 * need. As a prerequisite you should have at least a basic
53 * knowledge of the FLAC format, documented
54 * <A HREF="../format.html">here</A>.
56 * \section c_api FLAC C API
58 * The FLAC C API is the interface to libFLAC, a set of structures
59 * describing the components of FLAC streams, and functions for
60 * encoding and decoding streams, as well as manipulating FLAC
61 * metadata in files. The public include files will be installed
62 * in your include area as <include>/FLAC/...
64 * By writing a little code and linking against libFLAC, it is
65 * relatively easy to add FLAC support to another program. The
66 * library is licensed under <A HREF="../license.html">Xiph's BSD license</A>.
67 * Complete source code of libFLAC as well as the command-line
68 * encoder and plugins is available and is a useful source of
71 * Aside from encoders and decoders, libFLAC provides a powerful
72 * metadata interface for manipulating metadata in FLAC files. It
73 * allows the user to add, delete, and modify FLAC metadata blocks
74 * and it can automatically take advantage of PADDING blocks to avoid
75 * rewriting the entire FLAC file when changing the size of the
78 * libFLAC usually only requires the standard C library and C math
79 * library. In particular, threading is not used so there is no
80 * dependency on a thread library. However, libFLAC does not use
81 * global variables and should be thread-safe.
83 * There is also a libOggFLAC library which wraps around libFLAC
84 * to provide routines for encoding to and decoding from FLAC streams
85 * inside an Ogg container. The interfaces are very similar or identical
86 * to their counterparts in libFLAC. libOggFLAC is also licensed under
87 * <A HREF="../license.html">Xiph's BSD license</A>.
89 * \section cpp_api FLAC C++ API
91 * The FLAC C++ API is a set of classes that encapsulate the
92 * structures and functions in libFLAC. They provide slightly more
93 * functionality with respect to metadata but are otherwise
94 * equivalent. For the most part, they share the same usage as
95 * their counterparts in libFLAC, and the FLAC C API documentation
96 * can be used as a supplement. The public include files
97 * for the C++ API will be installed in your include area as
98 * <include>/FLAC++/...
100 * There is also a libOggFLAC++ library, which provides classes
101 * for encoding to and decoding from FLAC streams in an Ogg container.
102 * The classes are very similar to their counterparts in libFLAC++.
104 * Both libFLAC++ libOggFLAC++ are also licensed under
105 * <A HREF="../license.html">Xiph's BSD license</A>.
107 * \section getting_started Getting Started
109 * A good starting point for learning the API is to browse through
110 * the <A HREF="modules.html">modules</A>. Modules are logical
111 * groupings of related functions or classes, which correspond roughly
112 * to header files or sections of header files. Each module includes a
113 * detailed description of the general usage of its functions or
116 * From there you can go on to look at the documentation of
117 * individual functions. You can see different views of the individual
118 * functions through the links in top bar across this page.
120 * \section porting_guide Porting Guide
122 * Starting with FLAC 1.1.3 a \link porting Porting Guide \endlink
123 * has been introduced which gives detailed instructions on how to
124 * port your code to newer versions of FLAC.
126 * \section embedded_developers Embedded Developers
128 * libFLAC has grown larger over time as more functionality has been
129 * included, but much of it may be unnecessary for a particular embedded
130 * implementation. Unused parts may be pruned by some simple editing of
131 * src/libFLAC/Makefile.am. In general, the decoders, encoders, and
132 * metadata interface are all independent from each other.
134 * It is easiest to just describe the dependencies:
136 * - All modules depend on the \link flac_format Format \endlink module.
137 * - The decoders and encoders are independent of each other.
138 * - The metadata interface requires the file decoder.
139 * - The decoder and encoder layers depend on the layers below them, but
140 * not above them; e.g. the seekable stream decoder depends on the stream
141 * decoder but not the file decoder
143 * For example, if your application only requires the stream decoder, no
144 * encoders, and no metadata interface, you can remove the seekable stream
145 * decoder, file decoder, all encoders, and the metadata interface, which
146 * will greatly reduce the size of the library.
149 /** \defgroup porting Porting Guide for New Versions
151 * This module describes differences in the library interfaces from
152 * version to version. It assists in the porting of code that uses
153 * the libraries to newer versions of FLAC.
156 /** \defgroup porting_1_1_2_to_1_1_3 Porting from FLAC 1.1.2 to 1.1.3
160 * This module describes porting from FLAC 1.1.2 to FLAC 1.1.3.
162 * The main change between the APIs in 1.1.2 and 1.1.3 is that the three
163 * decoding layers and three encoding layers have been merged into a
164 * single stream decoder and stream encoder. That is, the functionality
165 * of FLAC__SeekableStreamDecoder and FLAC__FileDecoder has been merged
166 * into FLAC__StreamDecoder, and FLAC__SeekableStreamEncoder and
167 * FLAC__FileEncoder into FLAC__StreamEncoder. Only the
168 * FLAC__StreamDecoder and FLAC__StreamEncoder remain. This can
169 * simplify code that needs to process both seekable and non-seekable
172 * Instead of creating an encoder or decoder of a certain layer, now the
173 * client will always create a FLAC__StreamEncoder or
174 * FLAC__StreamDecoder. The different layers are differentiated by the
175 * initialization function. For example, for the decoder,
176 * FLAC__stream_decoder_init() has been replaced by
177 * FLAC__stream_decoder_init_stream(). This init function takes
178 * callbacks for the I/O, and the seeking callbacks are optional. This
179 * allows the client to use the same object for seekable and
180 * non-seekable streams. For decoding a FLAC file directly, the client
181 * can use FLAC__stream_decoder_init_file() and pass just a filename
182 * and fewer callbacks; most of the other callbacks are supplied
183 * internally. For situations where fopen()ing by filename is not
184 * possible (e.g. Unicode filenames on Windows) the client can instead
185 * open the file itself and supply the FILE* to
186 * FLAC__stream_decoder_init_FILE(). The init functions now returns a
187 * FLAC__StreamDecoderInitStatus instead of FLAC__StreamDecoderState.
188 * Since the callbacks and client data are now passed to the init
189 * function, the FLAC__stream_decoder_set_*_callback() functions and
190 * FLAC__stream_decoder_set_client_data() are no longer needed. The
191 * rest of the calls to the decoder are the same as before.
193 * As an example, in FLAC 1.1.2 a seekable stream decoder would be set
197 * FLAC__SeekableStreamDecoder *decoder = FLAC__seekable_stream_decoder_new();
198 * if(decoder == NULL) do_something;
199 * FLAC__seekable_stream_decoder_set_md5_checking(decoder, true);
200 * [... other settings ...]
201 * FLAC__seekable_stream_decoder_set_read_callback(decoder, my_read_callback);
202 * FLAC__seekable_stream_decoder_set_seek_callback(decoder, my_seek_callback);
203 * FLAC__seekable_stream_decoder_set_tell_callback(decoder, my_tell_callback);
204 * FLAC__seekable_stream_decoder_set_length_callback(decoder, my_length_callback);
205 * FLAC__seekable_stream_decoder_set_eof_callback(decoder, my_eof_callback);
206 * FLAC__seekable_stream_decoder_set_write_callback(decoder, my_write_callback);
207 * FLAC__seekable_stream_decoder_set_metadata_callback(decoder, my_metadata_callback);
208 * FLAC__seekable_stream_decoder_set_error_callback(decoder, my_error_callback);
209 * FLAC__seekable_stream_decoder_set_client_data(decoder, my_client_data);
210 * if(FLAC__seekable_stream_decoder_init(decoder) != FLAC__SEEKABLE_STREAM_DECODER_OK) do_something;
213 * In FLAC 1.1.3 it is like this:
216 * FLAC__StreamDecoder *decoder = FLAC__stream_decoder_new();
217 * if(decoder == NULL) do_something;
218 * FLAC__stream_decoder_set_md5_checking(decoder, true);
219 * [... other settings ...]
220 * if(FLAC__stream_decoder_init_stream(
223 * my_seek_callback, // or NULL
224 * my_tell_callback, // or NULL
225 * my_length_callback, // or NULL
226 * my_eof_callback, // or NULL
228 * my_metadata_callback, // or NULL
231 * ) != FLAC__STREAM_DECODER_INIT_STATUS_OK) do_something;
238 * FILE *file = fopen("somefile.flac","rb");
239 * if(file == NULL) do_somthing;
240 * if(FLAC__stream_decoder_init_FILE(
244 * my_metadata_callback, // or NULL
247 * ) != FLAC__STREAM_DECODER_INIT_STATUS_OK) do_something;
254 * if(FLAC__stream_decoder_init_FILE(
258 * my_metadata_callback, // or NULL
261 * ) != FLAC__STREAM_DECODER_INIT_STATUS_OK) do_something;
264 * Another small change to the decoder is in how it handles unparseable
265 * streams. Before, when the decoder found an unparseable stream
266 * (reserved for when the decoder encounters a stream from a future
267 * encoder that it can't parse), it changed the state to
268 * \c FLAC__STREAM_DECODER_UNPARSEABLE_STREAM. Now the decoder instead
269 * drops sync and calls the error callback with a new error code
270 * \c FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM. This is
271 * more robust. If your error callback does not discriminate on the the
272 * error state, your code does not need to be changed.
274 * The encoder now has a new setting:
275 * FLAC__stream_encoder_set_apodization(). This is for setting the
276 * method used to window the data before LPC analysis. You only need to
277 * add a call to this function if the default is not There are also
278 * two new convenience functions that may be useful:
279 * FLAC__metadata_object_cuesheet_calculate_cddb_id() and
280 * FLAC__metadata_get_cuesheet().
282 * In libOggFLAC++, OggFLAC::Decoder::Stream now inherits from
283 * FLAC::Decoder::Stream and OggFLAC::Encoder::Stream now inherits from
284 * FLAC::Encoder::Stream, which means both OggFLAC and FLAC can be
285 * supported by using common code for everything after initialization.
288 /** \defgroup flac FLAC C API
290 * The FLAC C API is the interface to libFLAC, a set of structures
291 * describing the components of FLAC streams, and functions for
292 * encoding and decoding streams, as well as manipulating FLAC
295 * You should start with the format components as all other modules
296 * are dependent on it.