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1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2001,2002,2003,2004,2005,2006,2007  Josh Coalson
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * - Redistributions of source code must retain the above copyright
9  * notice, this list of conditions and the following disclaimer.
10  *
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.
14  *
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.
18  *
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
23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef FLAC__METADATA_H
33 #define FLAC__METADATA_H
34 
35 #include <sys/types.h> /* for off_t */
36 #include "export.h"
37 #include "callback.h"
38 #include "format.h"
39 
40 /* --------------------------------------------------------------------
41    (For an example of how all these routines are used, see the source
42    code for the unit tests in src/test_libFLAC/metadata_*.c, or
43    metaflac in src/metaflac/)
44    ------------------------------------------------------------------*/
45 
46 /** \file include/FLAC/metadata.h
47  *
48  *  \brief
49  *  This module provides functions for creating and manipulating FLAC
50  *  metadata blocks in memory, and three progressively more powerful
51  *  interfaces for traversing and editing metadata in FLAC files.
52  *
53  *  See the detailed documentation for each interface in the
54  *  \link flac_metadata metadata \endlink module.
55  */
56 
57 /** \defgroup flac_metadata FLAC/metadata.h: metadata interfaces
58  *  \ingroup flac
59  *
60  *  \brief
61  *  This module provides functions for creating and manipulating FLAC
62  *  metadata blocks in memory, and three progressively more powerful
63  *  interfaces for traversing and editing metadata in native FLAC files.
64  *  Note that currently only the Chain interface (level 2) supports Ogg
65  *  FLAC files, and it is read-only i.e. no writing back changed
66  *  metadata to file.
67  *
68  *  There are three metadata interfaces of increasing complexity:
69  *
70  *  Level 0:
71  *  Read-only access to the STREAMINFO, VORBIS_COMMENT, CUESHEET, and
72  *  PICTURE blocks.
73  *
74  *  Level 1:
75  *  Read-write access to all metadata blocks.  This level is write-
76  *  efficient in most cases (more on this below), and uses less memory
77  *  than level 2.
78  *
79  *  Level 2:
80  *  Read-write access to all metadata blocks.  This level is write-
81  *  efficient in all cases, but uses more memory since all metadata for
82  *  the whole file is read into memory and manipulated before writing
83  *  out again.
84  *
85  *  What do we mean by efficient?  Since FLAC metadata appears at the
86  *  beginning of the file, when writing metadata back to a FLAC file
87  *  it is possible to grow or shrink the metadata such that the entire
88  *  file must be rewritten.  However, if the size remains the same during
89  *  changes or PADDING blocks are utilized, only the metadata needs to be
90  *  overwritten, which is much faster.
91  *
92  *  Efficient means the whole file is rewritten at most one time, and only
93  *  when necessary.  Level 1 is not efficient only in the case that you
94  *  cause more than one metadata block to grow or shrink beyond what can
95  *  be accomodated by padding.  In this case you should probably use level
96  *  2, which allows you to edit all the metadata for a file in memory and
97  *  write it out all at once.
98  *
99  *  All levels know how to skip over and not disturb an ID3v2 tag at the
100  *  front of the file.
101  *
102  *  All levels access files via their filenames.  In addition, level 2
103  *  has additional alternative read and write functions that take an I/O
104  *  handle and callbacks, for situations where access by filename is not
105  *  possible.
106  *
107  *  In addition to the three interfaces, this module defines functions for
108  *  creating and manipulating various metadata objects in memory.  As we see
109  *  from the Format module, FLAC metadata blocks in memory are very primitive
110  *  structures for storing information in an efficient way.  Reading
111  *  information from the structures is easy but creating or modifying them
112  *  directly is more complex.  The metadata object routines here facilitate
113  *  this by taking care of the consistency and memory management drudgery.
114  *
115  *  Unless you will be using the level 1 or 2 interfaces to modify existing
116  *  metadata however, you will not probably not need these.
117  *
118  *  From a dependency standpoint, none of the encoders or decoders require
119  *  the metadata module.  This is so that embedded users can strip out the
120  *  metadata module from libFLAC to reduce the size and complexity.
121  */
122 
123 #ifdef __cplusplus
124 extern "C" {
125 #endif
126 
127 
128 /** \defgroup flac_metadata_level0 FLAC/metadata.h: metadata level 0 interface
129  *  \ingroup flac_metadata
130  *
131  *  \brief
132  *  The level 0 interface consists of individual routines to read the
133  *  STREAMINFO, VORBIS_COMMENT, CUESHEET, and PICTURE blocks, requiring
134  *  only a filename.
135  *
136  *  They try to skip any ID3v2 tag at the head of the file.
137  *
138  * \{
139  */
140 
141 /** Read the STREAMINFO metadata block of the given FLAC file.  This function
142  *  will try to skip any ID3v2 tag at the head of the file.
143  *
144  * \param filename    The path to the FLAC file to read.
145  * \param streaminfo  A pointer to space for the STREAMINFO block.  Since
146  *                    FLAC__StreamMetadata is a simple structure with no
147  *                    memory allocation involved, you pass the address of
148  *                    an existing structure.  It need not be initialized.
149  * \assert
150  *    \code filename != NULL \endcode
151  *    \code streaminfo != NULL \endcode
152  * \retval FLAC__bool
153  *    \c true if a valid STREAMINFO block was read from \a filename.  Returns
154  *    \c false if there was a memory allocation error, a file decoder error,
155  *    or the file contained no STREAMINFO block.  (A memory allocation error
156  *    is possible because this function must set up a file decoder.)
157  */
158 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo);
159 
160 /** Read the VORBIS_COMMENT metadata block of the given FLAC file.  This
161  *  function will try to skip any ID3v2 tag at the head of the file.
162  *
163  * \param filename    The path to the FLAC file to read.
164  * \param tags        The address where the returned pointer will be
165  *                    stored.  The \a tags object must be deleted by
166  *                    the caller using FLAC__metadata_object_delete().
167  * \assert
168  *    \code filename != NULL \endcode
169  *    \code tags != NULL \endcode
170  * \retval FLAC__bool
171  *    \c true if a valid VORBIS_COMMENT block was read from \a filename,
172  *    and \a *tags will be set to the address of the metadata structure.
173  *    Returns \c false if there was a memory allocation error, a file
174  *    decoder error, or the file contained no VORBIS_COMMENT block, and
175  *    \a *tags will be set to \c NULL.
176  */
177 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags);
178 
179 /** Read the CUESHEET metadata block of the given FLAC file.  This
180  *  function will try to skip any ID3v2 tag at the head of the file.
181  *
182  * \param filename    The path to the FLAC file to read.
183  * \param cuesheet    The address where the returned pointer will be
184  *                    stored.  The \a cuesheet object must be deleted by
185  *                    the caller using FLAC__metadata_object_delete().
186  * \assert
187  *    \code filename != NULL \endcode
188  *    \code cuesheet != NULL \endcode
189  * \retval FLAC__bool
190  *    \c true if a valid CUESHEET block was read from \a filename,
191  *    and \a *cuesheet will be set to the address of the metadata
192  *    structure.  Returns \c false if there was a memory allocation
193  *    error, a file decoder error, or the file contained no CUESHEET
194  *    block, and \a *cuesheet will be set to \c NULL.
195  */
196 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet);
197 
198 /** Read a PICTURE metadata block of the given FLAC file.  This
199  *  function will try to skip any ID3v2 tag at the head of the file.
200  *  Since there can be more than one PICTURE block in a file, this
201  *  function takes a number of parameters that act as constraints to
202  *  the search.  The PICTURE block with the largest area matching all
203  *  the constraints will be returned, or \a *picture will be set to
204  *  \c NULL if there was no such block.
205  *
206  * \param filename    The path to the FLAC file to read.
207  * \param picture     The address where the returned pointer will be
208  *                    stored.  The \a picture object must be deleted by
209  *                    the caller using FLAC__metadata_object_delete().
210  * \param type        The desired picture type.  Use \c -1 to mean
211  *                    "any type".
212  * \param mime_type   The desired MIME type, e.g. "image/jpeg".  The
213  *                    string will be matched exactly.  Use \c NULL to
214  *                    mean "any MIME type".
215  * \param description The desired description.  The string will be
216  *                    matched exactly.  Use \c NULL to mean "any
217  *                    description".
218  * \param max_width   The maximum width in pixels desired.  Use
219  *                    \c (unsigned)(-1) to mean "any width".
220  * \param max_height  The maximum height in pixels desired.  Use
221  *                    \c (unsigned)(-1) to mean "any height".
222  * \param max_depth   The maximum color depth in bits-per-pixel desired.
223  *                    Use \c (unsigned)(-1) to mean "any depth".
224  * \param max_colors  The maximum number of colors desired.  Use
225  *                    \c (unsigned)(-1) to mean "any number of colors".
226  * \assert
227  *    \code filename != NULL \endcode
228  *    \code picture != NULL \endcode
229  * \retval FLAC__bool
230  *    \c true if a valid PICTURE block was read from \a filename,
231  *    and \a *picture will be set to the address of the metadata
232  *    structure.  Returns \c false if there was a memory allocation
233  *    error, a file decoder error, or the file contained no PICTURE
234  *    block, and \a *picture will be set to \c NULL.
235  */
236 FLAC_API FLAC__bool FLAC__metadata_get_picture(const char *filename, FLAC__StreamMetadata **picture, FLAC__StreamMetadata_Picture_Type type, const char *mime_type, const FLAC__byte *description, unsigned max_width, unsigned max_height, unsigned max_depth, unsigned max_colors);
237 
238 /* \} */
239 
240 
241 /** \defgroup flac_metadata_level1 FLAC/metadata.h: metadata level 1 interface
242  *  \ingroup flac_metadata
243  *
244  * \brief
245  * The level 1 interface provides read-write access to FLAC file metadata and
246  * operates directly on the FLAC file.
247  *
248  * The general usage of this interface is:
249  *
250  * - Create an iterator using FLAC__metadata_simple_iterator_new()
251  * - Attach it to a file using FLAC__metadata_simple_iterator_init() and check
252  *   the exit code.  Call FLAC__metadata_simple_iterator_is_writable() to
253  *   see if the file is writable, or only read access is allowed.
254  * - Use FLAC__metadata_simple_iterator_next() and
255  *   FLAC__metadata_simple_iterator_prev() to traverse the blocks.
256  *   This is does not read the actual blocks themselves.
257  *   FLAC__metadata_simple_iterator_next() is relatively fast.
258  *   FLAC__metadata_simple_iterator_prev() is slower since it needs to search
259  *   forward from the front of the file.
260  * - Use FLAC__metadata_simple_iterator_get_block_type() or
261  *   FLAC__metadata_simple_iterator_get_block() to access the actual data at
262  *   the current iterator position.  The returned object is yours to modify
263  *   and free.
264  * - Use FLAC__metadata_simple_iterator_set_block() to write a modified block
265  *   back.  You must have write permission to the original file.  Make sure to
266  *   read the whole comment to FLAC__metadata_simple_iterator_set_block()
267  *   below.
268  * - Use FLAC__metadata_simple_iterator_insert_block_after() to add new blocks.
269  *   Use the object creation functions from
270  *   \link flac_metadata_object here \endlink to generate new objects.
271  * - Use FLAC__metadata_simple_iterator_delete_block() to remove the block
272  *   currently referred to by the iterator, or replace it with padding.
273  * - Destroy the iterator with FLAC__metadata_simple_iterator_delete() when
274  *   finished.
275  *
276  * \note
277  * The FLAC file remains open the whole time between
278  * FLAC__metadata_simple_iterator_init() and
279  * FLAC__metadata_simple_iterator_delete(), so make sure you are not altering
280  * the file during this time.
281  *
282  * \note
283  * Do not modify the \a is_last, \a length, or \a type fields of returned
284  * FLAC__StreamMetadata objects.  These are managed automatically.
285  *
286  * \note
287  * If any of the modification functions
288  * (FLAC__metadata_simple_iterator_set_block(),
289  * FLAC__metadata_simple_iterator_delete_block(),
290  * FLAC__metadata_simple_iterator_insert_block_after(), etc.) return \c false,
291  * you should delete the iterator as it may no longer be valid.
292  *
293  * \{
294  */
295 
296 struct FLAC__Metadata_SimpleIterator;
297 /** The opaque structure definition for the level 1 iterator type.
298  *  See the
299  *  \link flac_metadata_level1 metadata level 1 module \endlink
300  *  for a detailed description.
301  */
302 typedef struct FLAC__Metadata_SimpleIterator FLAC__Metadata_SimpleIterator;
303 
304 /** Status type for FLAC__Metadata_SimpleIterator.
305  *
306  *  The iterator's current status can be obtained by calling FLAC__metadata_simple_iterator_status().
307  */
308 typedef enum {
309 
310 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK = 0,
311 	/**< The iterator is in the normal OK state */
312 
313 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT,
314 	/**< The data passed into a function violated the function's usage criteria */
315 
316 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE,
317 	/**< The iterator could not open the target file */
318 
319 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE,
320 	/**< The iterator could not find the FLAC signature at the start of the file */
321 
322 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE,
323 	/**< The iterator tried to write to a file that was not writable */
324 
325 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA,
326 	/**< The iterator encountered input that does not conform to the FLAC metadata specification */
327 
328 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR,
329 	/**< The iterator encountered an error while reading the FLAC file */
330 
331 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR,
332 	/**< The iterator encountered an error while seeking in the FLAC file */
333 
334 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR,
335 	/**< The iterator encountered an error while writing the FLAC file */
336 
337 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR,
338 	/**< The iterator encountered an error renaming the FLAC file */
339 
340 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR,
341 	/**< The iterator encountered an error removing the temporary file */
342 
343 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR,
344 	/**< Memory allocation failed */
345 
346 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR
347 	/**< The caller violated an assertion or an unexpected error occurred */
348 
349 } FLAC__Metadata_SimpleIteratorStatus;
350 
351 /** Maps a FLAC__Metadata_SimpleIteratorStatus to a C string.
352  *
353  *  Using a FLAC__Metadata_SimpleIteratorStatus as the index to this array
354  *  will give the string equivalent.  The contents should not be modified.
355  */
356 extern FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[];
357 
358 
359 /** Create a new iterator instance.
360  *
361  * \retval FLAC__Metadata_SimpleIterator*
362  *    \c NULL if there was an error allocating memory, else the new instance.
363  */
364 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void);
365 
366 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
367  *
368  * \param iterator  A pointer to an existing iterator.
369  * \assert
370  *    \code iterator != NULL \endcode
371  */
372 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator);
373 
374 /** Get the current status of the iterator.  Call this after a function
375  *  returns \c false to get the reason for the error.  Also resets the status
376  *  to FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK.
377  *
378  * \param iterator  A pointer to an existing iterator.
379  * \assert
380  *    \code iterator != NULL \endcode
381  * \retval FLAC__Metadata_SimpleIteratorStatus
382  *    The current status of the iterator.
383  */
384 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator);
385 
386 /** Initialize the iterator to point to the first metadata block in the
387  *  given FLAC file.
388  *
389  * \param iterator             A pointer to an existing iterator.
390  * \param filename             The path to the FLAC file.
391  * \param read_only            If \c true, the FLAC file will be opened
392  *                             in read-only mode; if \c false, the FLAC
393  *                             file will be opened for edit even if no
394  *                             edits are performed.
395  * \param preserve_file_stats  If \c true, the owner and modification
396  *                             time will be preserved even if the FLAC
397  *                             file is written to.
398  * \assert
399  *    \code iterator != NULL \endcode
400  *    \code filename != NULL \endcode
401  * \retval FLAC__bool
402  *    \c false if a memory allocation error occurs, the file can't be
403  *    opened, or another error occurs, else \c true.
404  */
405 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_init(FLAC__Metadata_SimpleIterator *iterator, const char *filename, FLAC__bool read_only, FLAC__bool preserve_file_stats);
406 
407 /** Returns \c true if the FLAC file is writable.  If \c false, calls to
408  *  FLAC__metadata_simple_iterator_set_block() and
409  *  FLAC__metadata_simple_iterator_insert_block_after() will fail.
410  *
411  * \param iterator             A pointer to an existing iterator.
412  * \assert
413  *    \code iterator != NULL \endcode
414  * \retval FLAC__bool
415  *    See above.
416  */
417 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator);
418 
419 /** Moves the iterator forward one metadata block, returning \c false if
420  *  already at the end.
421  *
422  * \param iterator  A pointer to an existing initialized iterator.
423  * \assert
424  *    \code iterator != NULL \endcode
425  *    \a iterator has been successfully initialized with
426  *    FLAC__metadata_simple_iterator_init()
427  * \retval FLAC__bool
428  *    \c false if already at the last metadata block of the chain, else
429  *    \c true.
430  */
431 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator);
432 
433 /** Moves the iterator backward one metadata block, returning \c false if
434  *  already at the beginning.
435  *
436  * \param iterator  A pointer to an existing initialized iterator.
437  * \assert
438  *    \code iterator != NULL \endcode
439  *    \a iterator has been successfully initialized with
440  *    FLAC__metadata_simple_iterator_init()
441  * \retval FLAC__bool
442  *    \c false if already at the first metadata block of the chain, else
443  *    \c true.
444  */
445 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator);
446 
447 /** Returns a flag telling if the current metadata block is the last.
448  *
449  * \param iterator  A pointer to an existing initialized iterator.
450  * \assert
451  *    \code iterator != NULL \endcode
452  *    \a iterator has been successfully initialized with
453  *    FLAC__metadata_simple_iterator_init()
454  * \retval FLAC__bool
455  *    \c true if the current metadata block is the last in the file,
456  *    else \c false.
457  */
458 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator);
459 
460 /** Get the offset of the metadata block at the current position.  This
461  *  avoids reading the actual block data which can save time for large
462  *  blocks.
463  *
464  * \param iterator  A pointer to an existing initialized iterator.
465  * \assert
466  *    \code iterator != NULL \endcode
467  *    \a iterator has been successfully initialized with
468  *    FLAC__metadata_simple_iterator_init()
469  * \retval off_t
470  *    The offset of the metadata block at the current iterator position.
471  *    This is the byte offset relative to the beginning of the file of
472  *    the current metadata block's header.
473  */
474 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator);
475 
476 /** Get the type of the metadata block at the current position.  This
477  *  avoids reading the actual block data which can save time for large
478  *  blocks.
479  *
480  * \param iterator  A pointer to an existing initialized iterator.
481  * \assert
482  *    \code iterator != NULL \endcode
483  *    \a iterator has been successfully initialized with
484  *    FLAC__metadata_simple_iterator_init()
485  * \retval FLAC__MetadataType
486  *    The type of the metadata block at the current iterator position.
487  */
488 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator);
489 
490 /** Get the length of the metadata block at the current position.  This
491  *  avoids reading the actual block data which can save time for large
492  *  blocks.
493  *
494  * \param iterator  A pointer to an existing initialized iterator.
495  * \assert
496  *    \code iterator != NULL \endcode
497  *    \a iterator has been successfully initialized with
498  *    FLAC__metadata_simple_iterator_init()
499  * \retval unsigned
500  *    The length of the metadata block at the current iterator position.
501  *    The is same length as that in the
502  *    <a href="http://flac.sourceforge.net/format.html#metadata_block_header">metadata block header</a>,
503  *    i.e. the length of the metadata body that follows the header.
504  */
505 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator);
506 
507 /** Get the application ID of the \c APPLICATION block at the current
508  *  position.  This avoids reading the actual block data which can save
509  *  time for large blocks.
510  *
511  * \param iterator  A pointer to an existing initialized iterator.
512  * \param id        A pointer to a buffer of at least \c 4 bytes where
513  *                  the ID will be stored.
514  * \assert
515  *    \code iterator != NULL \endcode
516  *    \code id != NULL \endcode
517  *    \a iterator has been successfully initialized with
518  *    FLAC__metadata_simple_iterator_init()
519  * \retval FLAC__bool
520  *    \c true if the ID was successfully read, else \c false, in which
521  *    case you should check FLAC__metadata_simple_iterator_status() to
522  *    find out why.  If the status is
523  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT, then the
524  *    current metadata block is not an \c APPLICATION block.  Otherwise
525  *    if the status is
526  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR or
527  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR, an I/O error
528  *    occurred and the iterator can no longer be used.
529  */
530 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id);
531 
532 /** Get the metadata block at the current position.  You can modify the
533  *  block but must use FLAC__metadata_simple_iterator_set_block() to
534  *  write it back to the FLAC file.
535  *
536  *  You must call FLAC__metadata_object_delete() on the returned object
537  *  when you are finished with it.
538  *
539  * \param iterator  A pointer to an existing initialized iterator.
540  * \assert
541  *    \code iterator != NULL \endcode
542  *    \a iterator has been successfully initialized with
543  *    FLAC__metadata_simple_iterator_init()
544  * \retval FLAC__StreamMetadata*
545  *    The current metadata block, or \c NULL if there was a memory
546  *    allocation error.
547  */
548 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator);
549 
550 /** Write a block back to the FLAC file.  This function tries to be
551  *  as efficient as possible; how the block is actually written is
552  *  shown by the following:
553  *
554  *  Existing block is a STREAMINFO block and the new block is a
555  *  STREAMINFO block: the new block is written in place.  Make sure
556  *  you know what you're doing when changing the values of a
557  *  STREAMINFO block.
558  *
559  *  Existing block is a STREAMINFO block and the new block is a
560  *  not a STREAMINFO block: this is an error since the first block
561  *  must be a STREAMINFO block.  Returns \c false without altering the
562  *  file.
563  *
564  *  Existing block is not a STREAMINFO block and the new block is a
565  *  STREAMINFO block: this is an error since there may be only one
566  *  STREAMINFO block.  Returns \c false without altering the file.
567  *
568  *  Existing block and new block are the same length: the existing
569  *  block will be replaced by the new block, written in place.
570  *
571  *  Existing block is longer than new block: if use_padding is \c true,
572  *  the existing block will be overwritten in place with the new
573  *  block followed by a PADDING block, if possible, to make the total
574  *  size the same as the existing block.  Remember that a padding
575  *  block requires at least four bytes so if the difference in size
576  *  between the new block and existing block is less than that, the
577  *  entire file will have to be rewritten, using the new block's
578  *  exact size.  If use_padding is \c false, the entire file will be
579  *  rewritten, replacing the existing block by the new block.
580  *
581  *  Existing block is shorter than new block: if use_padding is \c true,
582  *  the function will try and expand the new block into the following
583  *  PADDING block, if it exists and doing so won't shrink the PADDING
584  *  block to less than 4 bytes.  If there is no following PADDING
585  *  block, or it will shrink to less than 4 bytes, or use_padding is
586  *  \c false, the entire file is rewritten, replacing the existing block
587  *  with the new block.  Note that in this case any following PADDING
588  *  block is preserved as is.
589  *
590  *  After writing the block, the iterator will remain in the same
591  *  place, i.e. pointing to the new block.
592  *
593  * \param iterator     A pointer to an existing initialized iterator.
594  * \param block        The block to set.
595  * \param use_padding  See above.
596  * \assert
597  *    \code iterator != NULL \endcode
598  *    \a iterator has been successfully initialized with
599  *    FLAC__metadata_simple_iterator_init()
600  *    \code block != NULL \endcode
601  * \retval FLAC__bool
602  *    \c true if successful, else \c false.
603  */
604 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
605 
606 /** This is similar to FLAC__metadata_simple_iterator_set_block()
607  *  except that instead of writing over an existing block, it appends
608  *  a block after the existing block.  \a use_padding is again used to
609  *  tell the function to try an expand into following padding in an
610  *  attempt to avoid rewriting the entire file.
611  *
612  *  This function will fail and return \c false if given a STREAMINFO
613  *  block.
614  *
615  *  After writing the block, the iterator will be pointing to the
616  *  new block.
617  *
618  * \param iterator     A pointer to an existing initialized iterator.
619  * \param block        The block to set.
620  * \param use_padding  See above.
621  * \assert
622  *    \code iterator != NULL \endcode
623  *    \a iterator has been successfully initialized with
624  *    FLAC__metadata_simple_iterator_init()
625  *    \code block != NULL \endcode
626  * \retval FLAC__bool
627  *    \c true if successful, else \c false.
628  */
629 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
630 
631 /** Deletes the block at the current position.  This will cause the
632  *  entire FLAC file to be rewritten, unless \a use_padding is \c true,
633  *  in which case the block will be replaced by an equal-sized PADDING
634  *  block.  The iterator will be left pointing to the block before the
635  *  one just deleted.
636  *
637  *  You may not delete the STREAMINFO block.
638  *
639  * \param iterator     A pointer to an existing initialized iterator.
640  * \param use_padding  See above.
641  * \assert
642  *    \code iterator != NULL \endcode
643  *    \a iterator has been successfully initialized with
644  *    FLAC__metadata_simple_iterator_init()
645  * \retval FLAC__bool
646  *    \c true if successful, else \c false.
647  */
648 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding);
649 
650 /* \} */
651 
652 
653 /** \defgroup flac_metadata_level2 FLAC/metadata.h: metadata level 2 interface
654  *  \ingroup flac_metadata
655  *
656  * \brief
657  * The level 2 interface provides read-write access to FLAC file metadata;
658  * all metadata is read into memory, operated on in memory, and then written
659  * to file, which is more efficient than level 1 when editing multiple blocks.
660  *
661  * Currently Ogg FLAC is supported for read only, via
662  * FLAC__metadata_chain_read_ogg() but a subsequent
663  * FLAC__metadata_chain_write() will fail.
664  *
665  * The general usage of this interface is:
666  *
667  * - Create a new chain using FLAC__metadata_chain_new().  A chain is a
668  *   linked list of FLAC metadata blocks.
669  * - Read all metadata into the the chain from a FLAC file using
670  *   FLAC__metadata_chain_read() or FLAC__metadata_chain_read_ogg() and
671  *   check the status.
672  * - Optionally, consolidate the padding using
673  *   FLAC__metadata_chain_merge_padding() or
674  *   FLAC__metadata_chain_sort_padding().
675  * - Create a new iterator using FLAC__metadata_iterator_new()
676  * - Initialize the iterator to point to the first element in the chain
677  *   using FLAC__metadata_iterator_init()
678  * - Traverse the chain using FLAC__metadata_iterator_next and
679  *   FLAC__metadata_iterator_prev().
680  * - Get a block for reading or modification using
681  *   FLAC__metadata_iterator_get_block().  The pointer to the object
682  *   inside the chain is returned, so the block is yours to modify.
683  *   Changes will be reflected in the FLAC file when you write the
684  *   chain.  You can also add and delete blocks (see functions below).
685  * - When done, write out the chain using FLAC__metadata_chain_write().
686  *   Make sure to read the whole comment to the function below.
687  * - Delete the chain using FLAC__metadata_chain_delete().
688  *
689  * \note
690  * Even though the FLAC file is not open while the chain is being
691  * manipulated, you must not alter the file externally during
692  * this time.  The chain assumes the FLAC file will not change
693  * between the time of FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg()
694  * and FLAC__metadata_chain_write().
695  *
696  * \note
697  * Do not modify the is_last, length, or type fields of returned
698  * FLAC__StreamMetadata objects.  These are managed automatically.
699  *
700  * \note
701  * The metadata objects returned by FLAC__metadata_iterator_get_block()
702  * are owned by the chain; do not FLAC__metadata_object_delete() them.
703  * In the same way, blocks passed to FLAC__metadata_iterator_set_block()
704  * become owned by the chain and they will be deleted when the chain is
705  * deleted.
706  *
707  * \{
708  */
709 
710 struct FLAC__Metadata_Chain;
711 /** The opaque structure definition for the level 2 chain type.
712  */
713 typedef struct FLAC__Metadata_Chain FLAC__Metadata_Chain;
714 
715 struct FLAC__Metadata_Iterator;
716 /** The opaque structure definition for the level 2 iterator type.
717  */
718 typedef struct FLAC__Metadata_Iterator FLAC__Metadata_Iterator;
719 
720 typedef enum {
721 	FLAC__METADATA_CHAIN_STATUS_OK = 0,
722 	/**< The chain is in the normal OK state */
723 
724 	FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT,
725 	/**< The data passed into a function violated the function's usage criteria */
726 
727 	FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE,
728 	/**< The chain could not open the target file */
729 
730 	FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE,
731 	/**< The chain could not find the FLAC signature at the start of the file */
732 
733 	FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE,
734 	/**< The chain tried to write to a file that was not writable */
735 
736 	FLAC__METADATA_CHAIN_STATUS_BAD_METADATA,
737 	/**< The chain encountered input that does not conform to the FLAC metadata specification */
738 
739 	FLAC__METADATA_CHAIN_STATUS_READ_ERROR,
740 	/**< The chain encountered an error while reading the FLAC file */
741 
742 	FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR,
743 	/**< The chain encountered an error while seeking in the FLAC file */
744 
745 	FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR,
746 	/**< The chain encountered an error while writing the FLAC file */
747 
748 	FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR,
749 	/**< The chain encountered an error renaming the FLAC file */
750 
751 	FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR,
752 	/**< The chain encountered an error removing the temporary file */
753 
754 	FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR,
755 	/**< Memory allocation failed */
756 
757 	FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR,
758 	/**< The caller violated an assertion or an unexpected error occurred */
759 
760 	FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS,
761 	/**< One or more of the required callbacks was NULL */
762 
763 	FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH,
764 	/**< FLAC__metadata_chain_write() was called on a chain read by
765 	 *   FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
766 	 *   or
767 	 *   FLAC__metadata_chain_write_with_callbacks()/FLAC__metadata_chain_write_with_callbacks_and_tempfile()
768 	 *   was called on a chain read by
769 	 *   FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
770 	 *   Matching read/write methods must always be used. */
771 
772 	FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL
773 	/**< FLAC__metadata_chain_write_with_callbacks() was called when the
774 	 *   chain write requires a tempfile; use
775 	 *   FLAC__metadata_chain_write_with_callbacks_and_tempfile() instead.
776 	 *   Or, FLAC__metadata_chain_write_with_callbacks_and_tempfile() was
777 	 *   called when the chain write does not require a tempfile; use
778 	 *   FLAC__metadata_chain_write_with_callbacks() instead.
779 	 *   Always check FLAC__metadata_chain_check_if_tempfile_needed()
780 	 *   before writing via callbacks. */
781 
782 } FLAC__Metadata_ChainStatus;
783 
784 /** Maps a FLAC__Metadata_ChainStatus to a C string.
785  *
786  *  Using a FLAC__Metadata_ChainStatus as the index to this array
787  *  will give the string equivalent.  The contents should not be modified.
788  */
789 extern FLAC_API const char * const FLAC__Metadata_ChainStatusString[];
790 
791 /*********** FLAC__Metadata_Chain ***********/
792 
793 /** Create a new chain instance.
794  *
795  * \retval FLAC__Metadata_Chain*
796  *    \c NULL if there was an error allocating memory, else the new instance.
797  */
798 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void);
799 
800 /** Free a chain instance.  Deletes the object pointed to by \a chain.
801  *
802  * \param chain  A pointer to an existing chain.
803  * \assert
804  *    \code chain != NULL \endcode
805  */
806 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain);
807 
808 /** Get the current status of the chain.  Call this after a function
809  *  returns \c false to get the reason for the error.  Also resets the
810  *  status to FLAC__METADATA_CHAIN_STATUS_OK.
811  *
812  * \param chain    A pointer to an existing chain.
813  * \assert
814  *    \code chain != NULL \endcode
815  * \retval FLAC__Metadata_ChainStatus
816  *    The current status of the chain.
817  */
818 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain);
819 
820 /** Read all metadata from a FLAC file into the chain.
821  *
822  * \param chain    A pointer to an existing chain.
823  * \param filename The path to the FLAC file to read.
824  * \assert
825  *    \code chain != NULL \endcode
826  *    \code filename != NULL \endcode
827  * \retval FLAC__bool
828  *    \c true if a valid list of metadata blocks was read from
829  *    \a filename, else \c false.  On failure, check the status with
830  *    FLAC__metadata_chain_status().
831  */
832 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename);
833 
834 /** Read all metadata from an Ogg FLAC file into the chain.
835  *
836  * \note Ogg FLAC metadata data writing is not supported yet and
837  * FLAC__metadata_chain_write() will fail.
838  *
839  * \param chain    A pointer to an existing chain.
840  * \param filename The path to the Ogg FLAC file to read.
841  * \assert
842  *    \code chain != NULL \endcode
843  *    \code filename != NULL \endcode
844  * \retval FLAC__bool
845  *    \c true if a valid list of metadata blocks was read from
846  *    \a filename, else \c false.  On failure, check the status with
847  *    FLAC__metadata_chain_status().
848  */
849 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename);
850 
851 /** Read all metadata from a FLAC stream into the chain via I/O callbacks.
852  *
853  *  The \a handle need only be open for reading, but must be seekable.
854  *  The equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
855  *  for Windows).
856  *
857  * \param chain    A pointer to an existing chain.
858  * \param handle   The I/O handle of the FLAC stream to read.  The
859  *                 handle will NOT be closed after the metadata is read;
860  *                 that is the duty of the caller.
861  * \param callbacks
862  *                 A set of callbacks to use for I/O.  The mandatory
863  *                 callbacks are \a read, \a seek, and \a tell.
864  * \assert
865  *    \code chain != NULL \endcode
866  * \retval FLAC__bool
867  *    \c true if a valid list of metadata blocks was read from
868  *    \a handle, else \c false.  On failure, check the status with
869  *    FLAC__metadata_chain_status().
870  */
871 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
872 
873 /** Read all metadata from an Ogg FLAC stream into the chain via I/O callbacks.
874  *
875  *  The \a handle need only be open for reading, but must be seekable.
876  *  The equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
877  *  for Windows).
878  *
879  * \note Ogg FLAC metadata data writing is not supported yet and
880  * FLAC__metadata_chain_write() will fail.
881  *
882  * \param chain    A pointer to an existing chain.
883  * \param handle   The I/O handle of the Ogg FLAC stream to read.  The
884  *                 handle will NOT be closed after the metadata is read;
885  *                 that is the duty of the caller.
886  * \param callbacks
887  *                 A set of callbacks to use for I/O.  The mandatory
888  *                 callbacks are \a read, \a seek, and \a tell.
889  * \assert
890  *    \code chain != NULL \endcode
891  * \retval FLAC__bool
892  *    \c true if a valid list of metadata blocks was read from
893  *    \a handle, else \c false.  On failure, check the status with
894  *    FLAC__metadata_chain_status().
895  */
896 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
897 
898 /** Checks if writing the given chain would require the use of a
899  *  temporary file, or if it could be written in place.
900  *
901  *  Under certain conditions, padding can be utilized so that writing
902  *  edited metadata back to the FLAC file does not require rewriting the
903  *  entire file.  If rewriting is required, then a temporary workfile is
904  *  required.  When writing metadata using callbacks, you must check
905  *  this function to know whether to call
906  *  FLAC__metadata_chain_write_with_callbacks() or
907  *  FLAC__metadata_chain_write_with_callbacks_and_tempfile().  When
908  *  writing with FLAC__metadata_chain_write(), the temporary file is
909  *  handled internally.
910  *
911  * \param chain    A pointer to an existing chain.
912  * \param use_padding
913  *                 Whether or not padding will be allowed to be used
914  *                 during the write.  The value of \a use_padding given
915  *                 here must match the value later passed to
916  *                 FLAC__metadata_chain_write_with_callbacks() or
917  *                 FLAC__metadata_chain_write_with_callbacks_with_tempfile().
918  * \assert
919  *    \code chain != NULL \endcode
920  * \retval FLAC__bool
921  *    \c true if writing the current chain would require a tempfile, or
922  *    \c false if metadata can be written in place.
923  */
924 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding);
925 
926 /** Write all metadata out to the FLAC file.  This function tries to be as
927  *  efficient as possible; how the metadata is actually written is shown by
928  *  the following:
929  *
930  *  If the current chain is the same size as the existing metadata, the new
931  *  data is written in place.
932  *
933  *  If the current chain is longer than the existing metadata, and
934  *  \a use_padding is \c true, and the last block is a PADDING block of
935  *  sufficient length, the function will truncate the final padding block
936  *  so that the overall size of the metadata is the same as the existing
937  *  metadata, and then just rewrite the metadata.  Otherwise, if not all of
938  *  the above conditions are met, the entire FLAC file must be rewritten.
939  *  If you want to use padding this way it is a good idea to call
940  *  FLAC__metadata_chain_sort_padding() first so that you have the maximum
941  *  amount of padding to work with, unless you need to preserve ordering
942  *  of the PADDING blocks for some reason.
943  *
944  *  If the current chain is shorter than the existing metadata, and
945  *  \a use_padding is \c true, and the final block is a PADDING block, the padding
946  *  is extended to make the overall size the same as the existing data.  If
947  *  \a use_padding is \c true and the last block is not a PADDING block, a new
948  *  PADDING block is added to the end of the new data to make it the same
949  *  size as the existing data (if possible, see the note to
950  *  FLAC__metadata_simple_iterator_set_block() about the four byte limit)
951  *  and the new data is written in place.  If none of the above apply or
952  *  \a use_padding is \c false, the entire FLAC file is rewritten.
953  *
954  *  If \a preserve_file_stats is \c true, the owner and modification time will
955  *  be preserved even if the FLAC file is written.
956  *
957  *  For this write function to be used, the chain must have been read with
958  *  FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg(), not
959  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks().
960  *
961  * \param chain               A pointer to an existing chain.
962  * \param use_padding         See above.
963  * \param preserve_file_stats See above.
964  * \assert
965  *    \code chain != NULL \endcode
966  * \retval FLAC__bool
967  *    \c true if the write succeeded, else \c false.  On failure,
968  *    check the status with FLAC__metadata_chain_status().
969  */
970 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats);
971 
972 /** Write all metadata out to a FLAC stream via callbacks.
973  *
974  *  (See FLAC__metadata_chain_write() for the details on how padding is
975  *  used to write metadata in place if possible.)
976  *
977  *  The \a handle must be open for updating and be seekable.  The
978  *  equivalent minimum stdio fopen() file mode is \c "r+" (or \c "r+b"
979  *  for Windows).
980  *
981  *  For this write function to be used, the chain must have been read with
982  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
983  *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
984  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
985  *  \c false.
986  *
987  * \param chain        A pointer to an existing chain.
988  * \param use_padding  See FLAC__metadata_chain_write()
989  * \param handle       The I/O handle of the FLAC stream to write.  The
990  *                     handle will NOT be closed after the metadata is
991  *                     written; that is the duty of the caller.
992  * \param callbacks    A set of callbacks to use for I/O.  The mandatory
993  *                     callbacks are \a write and \a seek.
994  * \assert
995  *    \code chain != NULL \endcode
996  * \retval FLAC__bool
997  *    \c true if the write succeeded, else \c false.  On failure,
998  *    check the status with FLAC__metadata_chain_status().
999  */
1000 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
1001 
1002 /** Write all metadata out to a FLAC stream via callbacks.
1003  *
1004  *  (See FLAC__metadata_chain_write() for the details on how padding is
1005  *  used to write metadata in place if possible.)
1006  *
1007  *  This version of the write-with-callbacks function must be used when
1008  *  FLAC__metadata_chain_check_if_tempfile_needed() returns true.  In
1009  *  this function, you must supply an I/O handle corresponding to the
1010  *  FLAC file to edit, and a temporary handle to which the new FLAC
1011  *  file will be written.  It is the caller's job to move this temporary
1012  *  FLAC file on top of the original FLAC file to complete the metadata
1013  *  edit.
1014  *
1015  *  The \a handle must be open for reading and be seekable.  The
1016  *  equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
1017  *  for Windows).
1018  *
1019  *  The \a temp_handle must be open for writing.  The
1020  *  equivalent minimum stdio fopen() file mode is \c "w" (or \c "wb"
1021  *  for Windows).  It should be an empty stream, or at least positioned
1022  *  at the start-of-file (in which case it is the caller's duty to
1023  *  truncate it on return).
1024  *
1025  *  For this write function to be used, the chain must have been read with
1026  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
1027  *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
1028  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
1029  *  \c true.
1030  *
1031  * \param chain        A pointer to an existing chain.
1032  * \param use_padding  See FLAC__metadata_chain_write()
1033  * \param handle       The I/O handle of the original FLAC stream to read.
1034  *                     The handle will NOT be closed after the metadata is
1035  *                     written; that is the duty of the caller.
1036  * \param callbacks    A set of callbacks to use for I/O on \a handle.
1037  *                     The mandatory callbacks are \a read, \a seek, and
1038  *                     \a eof.
1039  * \param temp_handle  The I/O handle of the FLAC stream to write.  The
1040  *                     handle will NOT be closed after the metadata is
1041  *                     written; that is the duty of the caller.
1042  * \param temp_callbacks
1043  *                     A set of callbacks to use for I/O on temp_handle.
1044  *                     The only mandatory callback is \a write.
1045  * \assert
1046  *    \code chain != NULL \endcode
1047  * \retval FLAC__bool
1048  *    \c true if the write succeeded, else \c false.  On failure,
1049  *    check the status with FLAC__metadata_chain_status().
1050  */
1051 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks_and_tempfile(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks, FLAC__IOHandle temp_handle, FLAC__IOCallbacks temp_callbacks);
1052 
1053 /** Merge adjacent PADDING blocks into a single block.
1054  *
1055  * \note This function does not write to the FLAC file, it only
1056  * modifies the chain.
1057  *
1058  * \warning Any iterator on the current chain will become invalid after this
1059  * call.  You should delete the iterator and get a new one.
1060  *
1061  * \param chain               A pointer to an existing chain.
1062  * \assert
1063  *    \code chain != NULL \endcode
1064  */
1065 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain);
1066 
1067 /** This function will move all PADDING blocks to the end on the metadata,
1068  *  then merge them into a single block.
1069  *
1070  * \note This function does not write to the FLAC file, it only
1071  * modifies the chain.
1072  *
1073  * \warning Any iterator on the current chain will become invalid after this
1074  * call.  You should delete the iterator and get a new one.
1075  *
1076  * \param chain  A pointer to an existing chain.
1077  * \assert
1078  *    \code chain != NULL \endcode
1079  */
1080 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain);
1081 
1082 
1083 /*********** FLAC__Metadata_Iterator ***********/
1084 
1085 /** Create a new iterator instance.
1086  *
1087  * \retval FLAC__Metadata_Iterator*
1088  *    \c NULL if there was an error allocating memory, else the new instance.
1089  */
1090 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void);
1091 
1092 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
1093  *
1094  * \param iterator  A pointer to an existing iterator.
1095  * \assert
1096  *    \code iterator != NULL \endcode
1097  */
1098 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator);
1099 
1100 /** Initialize the iterator to point to the first metadata block in the
1101  *  given chain.
1102  *
1103  * \param iterator  A pointer to an existing iterator.
1104  * \param chain     A pointer to an existing and initialized (read) chain.
1105  * \assert
1106  *    \code iterator != NULL \endcode
1107  *    \code chain != NULL \endcode
1108  */
1109 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain);
1110 
1111 /** Moves the iterator forward one metadata block, returning \c false if
1112  *  already at the end.
1113  *
1114  * \param iterator  A pointer to an existing initialized iterator.
1115  * \assert
1116  *    \code iterator != NULL \endcode
1117  *    \a iterator has been successfully initialized with
1118  *    FLAC__metadata_iterator_init()
1119  * \retval FLAC__bool
1120  *    \c false if already at the last metadata block of the chain, else
1121  *    \c true.
1122  */
1123 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator);
1124 
1125 /** Moves the iterator backward one metadata block, returning \c false if
1126  *  already at the beginning.
1127  *
1128  * \param iterator  A pointer to an existing initialized iterator.
1129  * \assert
1130  *    \code iterator != NULL \endcode
1131  *    \a iterator has been successfully initialized with
1132  *    FLAC__metadata_iterator_init()
1133  * \retval FLAC__bool
1134  *    \c false if already at the first metadata block of the chain, else
1135  *    \c true.
1136  */
1137 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator);
1138 
1139 /** Get the type of the metadata block at the current position.
1140  *
1141  * \param iterator  A pointer to an existing initialized iterator.
1142  * \assert
1143  *    \code iterator != NULL \endcode
1144  *    \a iterator has been successfully initialized with
1145  *    FLAC__metadata_iterator_init()
1146  * \retval FLAC__MetadataType
1147  *    The type of the metadata block at the current iterator position.
1148  */
1149 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator);
1150 
1151 /** Get the metadata block at the current position.  You can modify
1152  *  the block in place but must write the chain before the changes
1153  *  are reflected to the FLAC file.  You do not need to call
1154  *  FLAC__metadata_iterator_set_block() to reflect the changes;
1155  *  the pointer returned by FLAC__metadata_iterator_get_block()
1156  *  points directly into the chain.
1157  *
1158  * \warning
1159  * Do not call FLAC__metadata_object_delete() on the returned object;
1160  * to delete a block use FLAC__metadata_iterator_delete_block().
1161  *
1162  * \param iterator  A pointer to an existing initialized iterator.
1163  * \assert
1164  *    \code iterator != NULL \endcode
1165  *    \a iterator has been successfully initialized with
1166  *    FLAC__metadata_iterator_init()
1167  * \retval FLAC__StreamMetadata*
1168  *    The current metadata block.
1169  */
1170 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator);
1171 
1172 /** Set the metadata block at the current position, replacing the existing
1173  *  block.  The new block passed in becomes owned by the chain and it will be
1174  *  deleted when the chain is deleted.
1175  *
1176  * \param iterator  A pointer to an existing initialized iterator.
1177  * \param block     A pointer to a metadata block.
1178  * \assert
1179  *    \code iterator != NULL \endcode
1180  *    \a iterator has been successfully initialized with
1181  *    FLAC__metadata_iterator_init()
1182  *    \code block != NULL \endcode
1183  * \retval FLAC__bool
1184  *    \c false if the conditions in the above description are not met, or
1185  *    a memory allocation error occurs, otherwise \c true.
1186  */
1187 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1188 
1189 /** Removes the current block from the chain.  If \a replace_with_padding is
1190  *  \c true, the block will instead be replaced with a padding block of equal
1191  *  size.  You can not delete the STREAMINFO block.  The iterator will be
1192  *  left pointing to the block before the one just "deleted", even if
1193  *  \a replace_with_padding is \c true.
1194  *
1195  * \param iterator              A pointer to an existing initialized iterator.
1196  * \param replace_with_padding  See above.
1197  * \assert
1198  *    \code iterator != NULL \endcode
1199  *    \a iterator has been successfully initialized with
1200  *    FLAC__metadata_iterator_init()
1201  * \retval FLAC__bool
1202  *    \c false if the conditions in the above description are not met,
1203  *    otherwise \c true.
1204  */
1205 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding);
1206 
1207 /** Insert a new block before the current block.  You cannot insert a block
1208  *  before the first STREAMINFO block.  You cannot insert a STREAMINFO block
1209  *  as there can be only one, the one that already exists at the head when you
1210  *  read in a chain.  The chain takes ownership of the new block and it will be
1211  *  deleted when the chain is deleted.  The iterator will be left pointing to
1212  *  the new block.
1213  *
1214  * \param iterator  A pointer to an existing initialized iterator.
1215  * \param block     A pointer to a metadata block to insert.
1216  * \assert
1217  *    \code iterator != NULL \endcode
1218  *    \a iterator has been successfully initialized with
1219  *    FLAC__metadata_iterator_init()
1220  * \retval FLAC__bool
1221  *    \c false if the conditions in the above description are not met, or
1222  *    a memory allocation error occurs, otherwise \c true.
1223  */
1224 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1225 
1226 /** Insert a new block after the current block.  You cannot insert a STREAMINFO
1227  *  block as there can be only one, the one that already exists at the head when
1228  *  you read in a chain.  The chain takes ownership of the new block and it will
1229  *  be deleted when the chain is deleted.  The iterator will be left pointing to
1230  *  the new block.
1231  *
1232  * \param iterator  A pointer to an existing initialized iterator.
1233  * \param block     A pointer to a metadata block to insert.
1234  * \assert
1235  *    \code iterator != NULL \endcode
1236  *    \a iterator has been successfully initialized with
1237  *    FLAC__metadata_iterator_init()
1238  * \retval FLAC__bool
1239  *    \c false if the conditions in the above description are not met, or
1240  *    a memory allocation error occurs, otherwise \c true.
1241  */
1242 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1243 
1244 /* \} */
1245 
1246 
1247 /** \defgroup flac_metadata_object FLAC/metadata.h: metadata object methods
1248  *  \ingroup flac_metadata
1249  *
1250  * \brief
1251  * This module contains methods for manipulating FLAC metadata objects.
1252  *
1253  * Since many are variable length we have to be careful about the memory
1254  * management.  We decree that all pointers to data in the object are
1255  * owned by the object and memory-managed by the object.
1256  *
1257  * Use the FLAC__metadata_object_new() and FLAC__metadata_object_delete()
1258  * functions to create all instances.  When using the
1259  * FLAC__metadata_object_set_*() functions to set pointers to data, set
1260  * \a copy to \c true to have the function make it's own copy of the data, or
1261  * to \c false to give the object ownership of your data.  In the latter case
1262  * your pointer must be freeable by free() and will be free()d when the object
1263  * is FLAC__metadata_object_delete()d.  It is legal to pass a null pointer as
1264  * the data pointer to a FLAC__metadata_object_set_*() function as long as
1265  * the length argument is 0 and the \a copy argument is \c false.
1266  *
1267  * The FLAC__metadata_object_new() and FLAC__metadata_object_clone() function
1268  * will return \c NULL in the case of a memory allocation error, otherwise a new
1269  * object.  The FLAC__metadata_object_set_*() functions return \c false in the
1270  * case of a memory allocation error.
1271  *
1272  * We don't have the convenience of C++ here, so note that the library relies
1273  * on you to keep the types straight.  In other words, if you pass, for
1274  * example, a FLAC__StreamMetadata* that represents a STREAMINFO block to
1275  * FLAC__metadata_object_application_set_data(), you will get an assertion
1276  * failure.
1277  *
1278  * For convenience the FLAC__metadata_object_vorbiscomment_*() functions
1279  * maintain a trailing NUL on each Vorbis comment entry.  This is not counted
1280  * toward the length or stored in the stream, but it can make working with plain
1281  * comments (those that don't contain embedded-NULs in the value) easier.
1282  * Entries passed into these functions have trailing NULs added if missing, and
1283  * returned entries are guaranteed to have a trailing NUL.
1284  *
1285  * The FLAC__metadata_object_vorbiscomment_*() functions that take a Vorbis
1286  * comment entry/name/value will first validate that it complies with the Vorbis
1287  * comment specification and return false if it does not.
1288  *
1289  * There is no need to recalculate the length field on metadata blocks you
1290  * have modified.  They will be calculated automatically before they  are
1291  * written back to a file.
1292  *
1293  * \{
1294  */
1295 
1296 
1297 /** Create a new metadata object instance of the given type.
1298  *
1299  *  The object will be "empty"; i.e. values and data pointers will be \c 0,
1300  *  with the exception of FLAC__METADATA_TYPE_VORBIS_COMMENT, which will have
1301  *  the vendor string set (but zero comments).
1302  *
1303  *  Do not pass in a value greater than or equal to
1304  *  \a FLAC__METADATA_TYPE_UNDEFINED unless you really know what you're
1305  *  doing.
1306  *
1307  * \param type  Type of object to create
1308  * \retval FLAC__StreamMetadata*
1309  *    \c NULL if there was an error allocating memory or the type code is
1310  *    greater than FLAC__MAX_METADATA_TYPE_CODE, else the new instance.
1311  */
1312 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_new(FLAC__MetadataType type);
1313 
1314 /** Create a copy of an existing metadata object.
1315  *
1316  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
1317  *  object is also copied.  The caller takes ownership of the new block and
1318  *  is responsible for freeing it with FLAC__metadata_object_delete().
1319  *
1320  * \param object  Pointer to object to copy.
1321  * \assert
1322  *    \code object != NULL \endcode
1323  * \retval FLAC__StreamMetadata*
1324  *    \c NULL if there was an error allocating memory, else the new instance.
1325  */
1326 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_clone(const FLAC__StreamMetadata *object);
1327 
1328 /** Free a metadata object.  Deletes the object pointed to by \a object.
1329  *
1330  *  The delete is a "deep" delete, i.e. dynamically allocated data within the
1331  *  object is also deleted.
1332  *
1333  * \param object  A pointer to an existing object.
1334  * \assert
1335  *    \code object != NULL \endcode
1336  */
1337 FLAC_API void FLAC__metadata_object_delete(FLAC__StreamMetadata *object);
1338 
1339 /** Compares two metadata objects.
1340  *
1341  *  The compare is "deep", i.e. dynamically allocated data within the
1342  *  object is also compared.
1343  *
1344  * \param block1  A pointer to an existing object.
1345  * \param block2  A pointer to an existing object.
1346  * \assert
1347  *    \code block1 != NULL \endcode
1348  *    \code block2 != NULL \endcode
1349  * \retval FLAC__bool
1350  *    \c true if objects are identical, else \c false.
1351  */
1352 FLAC_API FLAC__bool FLAC__metadata_object_is_equal(const FLAC__StreamMetadata *block1, const FLAC__StreamMetadata *block2);
1353 
1354 /** Sets the application data of an APPLICATION block.
1355  *
1356  *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
1357  *  takes ownership of the pointer.  The existing data will be freed if this
1358  *  function is successful, otherwise the original data will remain if \a copy
1359  *  is \c true and malloc() fails.
1360  *
1361  * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
1362  *
1363  * \param object  A pointer to an existing APPLICATION object.
1364  * \param data    A pointer to the data to set.
1365  * \param length  The length of \a data in bytes.
1366  * \param copy    See above.
1367  * \assert
1368  *    \code object != NULL \endcode
1369  *    \code object->type == FLAC__METADATA_TYPE_APPLICATION \endcode
1370  *    \code (data != NULL && length > 0) ||
1371  * (data == NULL && length == 0 && copy == false) \endcode
1372  * \retval FLAC__bool
1373  *    \c false if \a copy is \c true and malloc() fails, else \c true.
1374  */
1375 FLAC_API FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, unsigned length, FLAC__bool copy);
1376 
1377 /** Resize the seekpoint array.
1378  *
1379  *  If the size shrinks, elements will truncated; if it grows, new placeholder
1380  *  points will be added to the end.
1381  *
1382  * \param object          A pointer to an existing SEEKTABLE object.
1383  * \param new_num_points  The desired length of the array; may be \c 0.
1384  * \assert
1385  *    \code object != NULL \endcode
1386  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1387  *    \code (object->data.seek_table.points == NULL && object->data.seek_table.num_points == 0) ||
1388  * (object->data.seek_table.points != NULL && object->data.seek_table.num_points > 0) \endcode
1389  * \retval FLAC__bool
1390  *    \c false if memory allocation error, else \c true.
1391  */
1392 FLAC_API FLAC__bool FLAC__metadata_object_seektable_resize_points(FLAC__StreamMetadata *object, unsigned new_num_points);
1393 
1394 /** Set a seekpoint in a seektable.
1395  *
1396  * \param object     A pointer to an existing SEEKTABLE object.
1397  * \param point_num  Index into seekpoint array to set.
1398  * \param point      The point to set.
1399  * \assert
1400  *    \code object != NULL \endcode
1401  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1402  *    \code object->data.seek_table.num_points > point_num \endcode
1403  */
1404 FLAC_API void FLAC__metadata_object_seektable_set_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
1405 
1406 /** Insert a seekpoint into a seektable.
1407  *
1408  * \param object     A pointer to an existing SEEKTABLE object.
1409  * \param point_num  Index into seekpoint array to set.
1410  * \param point      The point to set.
1411  * \assert
1412  *    \code object != NULL \endcode
1413  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1414  *    \code object->data.seek_table.num_points >= point_num \endcode
1415  * \retval FLAC__bool
1416  *    \c false if memory allocation error, else \c true.
1417  */
1418 FLAC_API FLAC__bool FLAC__metadata_object_seektable_insert_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
1419 
1420 /** Delete a seekpoint from a seektable.
1421  *
1422  * \param object     A pointer to an existing SEEKTABLE object.
1423  * \param point_num  Index into seekpoint array to set.
1424  * \assert
1425  *    \code object != NULL \endcode
1426  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1427  *    \code object->data.seek_table.num_points > point_num \endcode
1428  * \retval FLAC__bool
1429  *    \c false if memory allocation error, else \c true.
1430  */
1431 FLAC_API FLAC__bool FLAC__metadata_object_seektable_delete_point(FLAC__StreamMetadata *object, unsigned point_num);
1432 
1433 /** Check a seektable to see if it conforms to the FLAC specification.
1434  *  See the format specification for limits on the contents of the
1435  *  seektable.
1436  *
1437  * \param object  A pointer to an existing SEEKTABLE object.
1438  * \assert
1439  *    \code object != NULL \endcode
1440  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1441  * \retval FLAC__bool
1442  *    \c false if seek table is illegal, else \c true.
1443  */
1444 FLAC_API FLAC__bool FLAC__metadata_object_seektable_is_legal(const FLAC__StreamMetadata *object);
1445 
1446 /** Append a number of placeholder points to the end of a seek table.
1447  *
1448  * \note
1449  * As with the other ..._seektable_template_... functions, you should
1450  * call FLAC__metadata_object_seektable_template_sort() when finished
1451  * to make the seek table legal.
1452  *
1453  * \param object  A pointer to an existing SEEKTABLE object.
1454  * \param num     The number of placeholder points to append.
1455  * \assert
1456  *    \code object != NULL \endcode
1457  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1458  * \retval FLAC__bool
1459  *    \c false if memory allocation fails, else \c true.
1460  */
1461 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_placeholders(FLAC__StreamMetadata *object, unsigned num);
1462 
1463 /** Append a specific seek point template to the end of a seek table.
1464  *
1465  * \note
1466  * As with the other ..._seektable_template_... functions, you should
1467  * call FLAC__metadata_object_seektable_template_sort() when finished
1468  * to make the seek table legal.
1469  *
1470  * \param object  A pointer to an existing SEEKTABLE object.
1471  * \param sample_number  The sample number of the seek point template.
1472  * \assert
1473  *    \code object != NULL \endcode
1474  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1475  * \retval FLAC__bool
1476  *    \c false if memory allocation fails, else \c true.
1477  */
1478 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_point(FLAC__StreamMetadata *object, FLAC__uint64 sample_number);
1479 
1480 /** Append specific seek point templates to the end of a seek table.
1481  *
1482  * \note
1483  * As with the other ..._seektable_template_... functions, you should
1484  * call FLAC__metadata_object_seektable_template_sort() when finished
1485  * to make the seek table legal.
1486  *
1487  * \param object  A pointer to an existing SEEKTABLE object.
1488  * \param sample_numbers  An array of sample numbers for the seek points.
1489  * \param num     The number of seek point templates to append.
1490  * \assert
1491  *    \code object != NULL \endcode
1492  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1493  * \retval FLAC__bool
1494  *    \c false if memory allocation fails, else \c true.
1495  */
1496 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_points(FLAC__StreamMetadata *object, FLAC__uint64 sample_numbers[], unsigned num);
1497 
1498 /** Append a set of evenly-spaced seek point templates to the end of a
1499  *  seek table.
1500  *
1501  * \note
1502  * As with the other ..._seektable_template_... functions, you should
1503  * call FLAC__metadata_object_seektable_template_sort() when finished
1504  * to make the seek table legal.
1505  *
1506  * \param object  A pointer to an existing SEEKTABLE object.
1507  * \param num     The number of placeholder points to append.
1508  * \param total_samples  The total number of samples to be encoded;
1509  *                       the seekpoints will be spaced approximately
1510  *                       \a total_samples / \a num samples apart.
1511  * \assert
1512  *    \code object != NULL \endcode
1513  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1514  *    \code total_samples > 0 \endcode
1515  * \retval FLAC__bool
1516  *    \c false if memory allocation fails, else \c true.
1517  */
1518 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points(FLAC__StreamMetadata *object, unsigned num, FLAC__uint64 total_samples);
1519 
1520 /** Append a set of evenly-spaced seek point templates to the end of a
1521  *  seek table.
1522  *
1523  * \note
1524  * As with the other ..._seektable_template_... functions, you should
1525  * call FLAC__metadata_object_seektable_template_sort() when finished
1526  * to make the seek table legal.
1527  *
1528  * \param object  A pointer to an existing SEEKTABLE object.
1529  * \param samples The number of samples apart to space the placeholder
1530  *                points.  The first point will be at sample \c 0, the
1531  *                second at sample \a samples, then 2*\a samples, and
1532  *                so on.  As long as \a samples and \a total_samples
1533  *                are greater than \c 0, there will always be at least
1534  *                one seekpoint at sample \c 0.
1535  * \param total_samples  The total number of samples to be encoded;
1536  *                       the seekpoints will be spaced
1537  *                       \a samples samples apart.
1538  * \assert
1539  *    \code object != NULL \endcode
1540  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1541  *    \code samples > 0 \endcode
1542  *    \code total_samples > 0 \endcode
1543  * \retval FLAC__bool
1544  *    \c false if memory allocation fails, else \c true.
1545  */
1546 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points_by_samples(FLAC__StreamMetadata *object, unsigned samples, FLAC__uint64 total_samples);
1547 
1548 /** Sort a seek table's seek points according to the format specification,
1549  *  removing duplicates.
1550  *
1551  * \param object   A pointer to a seek table to be sorted.
1552  * \param compact  If \c false, behaves like FLAC__format_seektable_sort().
1553  *                 If \c true, duplicates are deleted and the seek table is
1554  *                 shrunk appropriately; the number of placeholder points
1555  *                 present in the seek table will be the same after the call
1556  *                 as before.
1557  * \assert
1558  *    \code object != NULL \endcode
1559  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1560  * \retval FLAC__bool
1561  *    \c false if realloc() fails, else \c true.
1562  */
1563 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_sort(FLAC__StreamMetadata *object, FLAC__bool compact);
1564 
1565 /** Sets the vendor string in a VORBIS_COMMENT block.
1566  *
1567  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1568  *  one already.
1569  *
1570  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1571  *  takes ownership of the \c entry.entry pointer.
1572  *
1573  *  \note If this function returns \c false, the caller still owns the
1574  *  pointer.
1575  *
1576  * \param object  A pointer to an existing VORBIS_COMMENT object.
1577  * \param entry   The entry to set the vendor string to.
1578  * \param copy    See above.
1579  * \assert
1580  *    \code object != NULL \endcode
1581  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1582  *    \code (entry.entry != NULL && entry.length > 0) ||
1583  * (entry.entry == NULL && entry.length == 0) \endcode
1584  * \retval FLAC__bool
1585  *    \c false if memory allocation fails or \a entry does not comply with the
1586  *    Vorbis comment specification, else \c true.
1587  */
1588 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1589 
1590 /** Resize the comment array.
1591  *
1592  *  If the size shrinks, elements will truncated; if it grows, new empty
1593  *  fields will be added to the end.
1594  *
1595  * \param object            A pointer to an existing VORBIS_COMMENT object.
1596  * \param new_num_comments  The desired length of the array; may be \c 0.
1597  * \assert
1598  *    \code object != NULL \endcode
1599  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1600  *    \code (object->data.vorbis_comment.comments == NULL && object->data.vorbis_comment.num_comments == 0) ||
1601  * (object->data.vorbis_comment.comments != NULL && object->data.vorbis_comment.num_comments > 0) \endcode
1602  * \retval FLAC__bool
1603  *    \c false if memory allocation fails, else \c true.
1604  */
1605 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_resize_comments(FLAC__StreamMetadata *object, unsigned new_num_comments);
1606 
1607 /** Sets a comment in a VORBIS_COMMENT block.
1608  *
1609  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1610  *  one already.
1611  *
1612  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1613  *  takes ownership of the \c entry.entry pointer.
1614  *
1615  *  \note If this function returns \c false, the caller still owns the
1616  *  pointer.
1617  *
1618  * \param object       A pointer to an existing VORBIS_COMMENT object.
1619  * \param comment_num  Index into comment array to set.
1620  * \param entry        The entry to set the comment to.
1621  * \param copy         See above.
1622  * \assert
1623  *    \code object != NULL \endcode
1624  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1625  *    \code comment_num < object->data.vorbis_comment.num_comments \endcode
1626  *    \code (entry.entry != NULL && entry.length > 0) ||
1627  * (entry.entry == NULL && entry.length == 0) \endcode
1628  * \retval FLAC__bool
1629  *    \c false if memory allocation fails or \a entry does not comply with the
1630  *    Vorbis comment specification, else \c true.
1631  */
1632 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1633 
1634 /** Insert a comment in a VORBIS_COMMENT block at the given index.
1635  *
1636  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1637  *  one already.
1638  *
1639  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1640  *  takes ownership of the \c entry.entry pointer.
1641  *
1642  *  \note If this function returns \c false, the caller still owns the
1643  *  pointer.
1644  *
1645  * \param object       A pointer to an existing VORBIS_COMMENT object.
1646  * \param comment_num  The index at which to insert the comment.  The comments
1647  *                     at and after \a comment_num move right one position.
1648  *                     To append a comment to the end, set \a comment_num to
1649  *                     \c object->data.vorbis_comment.num_comments .
1650  * \param entry        The comment to insert.
1651  * \param copy         See above.
1652  * \assert
1653  *    \code object != NULL \endcode
1654  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1655  *    \code object->data.vorbis_comment.num_comments >= comment_num \endcode
1656  *    \code (entry.entry != NULL && entry.length > 0) ||
1657  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1658  * \retval FLAC__bool
1659  *    \c false if memory allocation fails or \a entry does not comply with the
1660  *    Vorbis comment specification, else \c true.
1661  */
1662 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_insert_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1663 
1664 /** Appends a comment to a VORBIS_COMMENT block.
1665  *
1666  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1667  *  one already.
1668  *
1669  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1670  *  takes ownership of the \c entry.entry pointer.
1671  *
1672  *  \note If this function returns \c false, the caller still owns the
1673  *  pointer.
1674  *
1675  * \param object       A pointer to an existing VORBIS_COMMENT object.
1676  * \param entry        The comment to insert.
1677  * \param copy         See above.
1678  * \assert
1679  *    \code object != NULL \endcode
1680  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1681  *    \code (entry.entry != NULL && entry.length > 0) ||
1682  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1683  * \retval FLAC__bool
1684  *    \c false if memory allocation fails or \a entry does not comply with the
1685  *    Vorbis comment specification, else \c true.
1686  */
1687 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_append_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1688 
1689 /** Replaces comments in a VORBIS_COMMENT block with a new one.
1690  *
1691  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1692  *  one already.
1693  *
1694  *  Depending on the the value of \a all, either all or just the first comment
1695  *  whose field name(s) match the given entry's name will be replaced by the
1696  *  given entry.  If no comments match, \a entry will simply be appended.
1697  *
1698  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1699  *  takes ownership of the \c entry.entry pointer.
1700  *
1701  *  \note If this function returns \c false, the caller still owns the
1702  *  pointer.
1703  *
1704  * \param object       A pointer to an existing VORBIS_COMMENT object.
1705  * \param entry        The comment to insert.
1706  * \param all          If \c true, all comments whose field name matches
1707  *                     \a entry's field name will be removed, and \a entry will
1708  *                     be inserted at the position of the first matching
1709  *                     comment.  If \c false, only the first comment whose
1710  *                     field name matches \a entry's field name will be
1711  *                     replaced with \a entry.
1712  * \param copy         See above.
1713  * \assert
1714  *    \code object != NULL \endcode
1715  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1716  *    \code (entry.entry != NULL && entry.length > 0) ||
1717  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1718  * \retval FLAC__bool
1719  *    \c false if memory allocation fails or \a entry does not comply with the
1720  *    Vorbis comment specification, else \c true.
1721  */
1722 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_replace_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool all, FLAC__bool copy);
1723 
1724 /** Delete a comment in a VORBIS_COMMENT block at the given index.
1725  *
1726  * \param object       A pointer to an existing VORBIS_COMMENT object.
1727  * \param comment_num  The index of the comment to delete.
1728  * \assert
1729  *    \code object != NULL \endcode
1730  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1731  *    \code object->data.vorbis_comment.num_comments > comment_num \endcode
1732  * \retval FLAC__bool
1733  *    \c false if realloc() fails, else \c true.
1734  */
1735 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_delete_comment(FLAC__StreamMetadata *object, unsigned comment_num);
1736 
1737 /** Creates a Vorbis comment entry from NUL-terminated name and value strings.
1738  *
1739  *  On return, the filled-in \a entry->entry pointer will point to malloc()ed
1740  *  memory and shall be owned by the caller.  For convenience the entry will
1741  *  have a terminating NUL.
1742  *
1743  * \param entry              A pointer to a Vorbis comment entry.  The entry's
1744  *                           \c entry pointer should not point to allocated
1745  *                           memory as it will be overwritten.
1746  * \param field_name         The field name in ASCII, \c NUL terminated.
1747  * \param field_value        The field value in UTF-8, \c NUL terminated.
1748  * \assert
1749  *    \code entry != NULL \endcode
1750  *    \code field_name != NULL \endcode
1751  *    \code field_value != NULL \endcode
1752  * \retval FLAC__bool
1753  *    \c false if malloc() fails, or if \a field_name or \a field_value does
1754  *    not comply with the Vorbis comment specification, else \c true.
1755  */
1756 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(FLAC__StreamMetadata_VorbisComment_Entry *entry, const char *field_name, const char *field_value);
1757 
1758 /** Splits a Vorbis comment entry into NUL-terminated name and value strings.
1759  *
1760  *  The returned pointers to name and value will be allocated by malloc()
1761  *  and shall be owned by the caller.
1762  *
1763  * \param entry              An existing Vorbis comment entry.
1764  * \param field_name         The address of where the returned pointer to the
1765  *                           field name will be stored.
1766  * \param field_value        The address of where the returned pointer to the
1767  *                           field value will be stored.
1768  * \assert
1769  *    \code (entry.entry != NULL && entry.length > 0) \endcode
1770  *    \code memchr(entry.entry, '=', entry.length) != NULL \endcode
1771  *    \code field_name != NULL \endcode
1772  *    \code field_value != NULL \endcode
1773  * \retval FLAC__bool
1774  *    \c false if memory allocation fails or \a entry does not comply with the
1775  *    Vorbis comment specification, else \c true.
1776  */
1777 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_to_name_value_pair(const FLAC__StreamMetadata_VorbisComment_Entry entry, char **field_name, char **field_value);
1778 
1779 /** Check if the given Vorbis comment entry's field name matches the given
1780  *  field name.
1781  *
1782  * \param entry              An existing Vorbis comment entry.
1783  * \param field_name         The field name to check.
1784  * \param field_name_length  The length of \a field_name, not including the
1785  *                           terminating \c NUL.
1786  * \assert
1787  *    \code (entry.entry != NULL && entry.length > 0) \endcode
1788  * \retval FLAC__bool
1789  *    \c true if the field names match, else \c false
1790  */
1791 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_matches(const FLAC__StreamMetadata_VorbisComment_Entry entry, const char *field_name, unsigned field_name_length);
1792 
1793 /** Find a Vorbis comment with the given field name.
1794  *
1795  *  The search begins at entry number \a offset; use an offset of 0 to
1796  *  search from the beginning of the comment array.
1797  *
1798  * \param object      A pointer to an existing VORBIS_COMMENT object.
1799  * \param offset      The offset into the comment array from where to start
1800  *                    the search.
1801  * \param field_name  The field name of the comment to find.
1802  * \assert
1803  *    \code object != NULL \endcode
1804  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1805  *    \code field_name != NULL \endcode
1806  * \retval int
1807  *    The offset in the comment array of the first comment whose field
1808  *    name matches \a field_name, or \c -1 if no match was found.
1809  */
1810 FLAC_API int FLAC__metadata_object_vorbiscomment_find_entry_from(const FLAC__StreamMetadata *object, unsigned offset, const char *field_name);
1811 
1812 /** Remove first Vorbis comment matching the given field name.
1813  *
1814  * \param object      A pointer to an existing VORBIS_COMMENT object.
1815  * \param field_name  The field name of comment to delete.
1816  * \assert
1817  *    \code object != NULL \endcode
1818  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1819  * \retval int
1820  *    \c -1 for memory allocation error, \c 0 for no matching entries,
1821  *    \c 1 for one matching entry deleted.
1822  */
1823 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entry_matching(FLAC__StreamMetadata *object, const char *field_name);
1824 
1825 /** Remove all Vorbis comments matching the given field name.
1826  *
1827  * \param object      A pointer to an existing VORBIS_COMMENT object.
1828  * \param field_name  The field name of comments to delete.
1829  * \assert
1830  *    \code object != NULL \endcode
1831  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1832  * \retval int
1833  *    \c -1 for memory allocation error, \c 0 for no matching entries,
1834  *    else the number of matching entries deleted.
1835  */
1836 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entries_matching(FLAC__StreamMetadata *object, const char *field_name);
1837 
1838 /** Create a new CUESHEET track instance.
1839  *
1840  *  The object will be "empty"; i.e. values and data pointers will be \c 0.
1841  *
1842  * \retval FLAC__StreamMetadata_CueSheet_Track*
1843  *    \c NULL if there was an error allocating memory, else the new instance.
1844  */
1845 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_new(void);
1846 
1847 /** Create a copy of an existing CUESHEET track object.
1848  *
1849  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
1850  *  object is also copied.  The caller takes ownership of the new object and
1851  *  is responsible for freeing it with
1852  *  FLAC__metadata_object_cuesheet_track_delete().
1853  *
1854  * \param object  Pointer to object to copy.
1855  * \assert
1856  *    \code object != NULL \endcode
1857  * \retval FLAC__StreamMetadata_CueSheet_Track*
1858  *    \c NULL if there was an error allocating memory, else the new instance.
1859  */
1860 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_clone(const FLAC__StreamMetadata_CueSheet_Track *object);
1861 
1862 /** Delete a CUESHEET track object
1863  *
1864  * \param object       A pointer to an existing CUESHEET track object.
1865  * \assert
1866  *    \code object != NULL \endcode
1867  */
1868 FLAC_API void FLAC__metadata_object_cuesheet_track_delete(FLAC__StreamMetadata_CueSheet_Track *object);
1869 
1870 /** Resize a track's index point array.
1871  *
1872  *  If the size shrinks, elements will truncated; if it grows, new blank
1873  *  indices will be added to the end.
1874  *
1875  * \param object           A pointer to an existing CUESHEET object.
1876  * \param track_num        The index of the track to modify.  NOTE: this is not
1877  *                         necessarily the same as the track's \a number field.
1878  * \param new_num_indices  The desired length of the array; may be \c 0.
1879  * \assert
1880  *    \code object != NULL \endcode
1881  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1882  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1883  *    \code (object->data.cue_sheet.tracks[track_num].indices == NULL && object->data.cue_sheet.tracks[track_num].num_indices == 0) ||
1884  * (object->data.cue_sheet.tracks[track_num].indices != NULL && object->data.cue_sheet.tracks[track_num].num_indices > 0) \endcode
1885  * \retval FLAC__bool
1886  *    \c false if memory allocation error, else \c true.
1887  */
1888 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_resize_indices(FLAC__StreamMetadata *object, unsigned track_num, unsigned new_num_indices);
1889 
1890 /** Insert an index point in a CUESHEET track at the given index.
1891  *
1892  * \param object       A pointer to an existing CUESHEET object.
1893  * \param track_num    The index of the track to modify.  NOTE: this is not
1894  *                     necessarily the same as the track's \a number field.
1895  * \param index_num    The index into the track's index array at which to
1896  *                     insert the index point.  NOTE: this is not necessarily
1897  *                     the same as the index point's \a number field.  The
1898  *                     indices at and after \a index_num move right one
1899  *                     position.  To append an index point to the end, set
1900  *                     \a index_num to
1901  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
1902  * \param index        The index point to insert.
1903  * \assert
1904  *    \code object != NULL \endcode
1905  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1906  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1907  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
1908  * \retval FLAC__bool
1909  *    \c false if realloc() fails, else \c true.
1910  */
1911 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num, FLAC__StreamMetadata_CueSheet_Index index);
1912 
1913 /** Insert a blank index point in a CUESHEET track at the given index.
1914  *
1915  *  A blank index point is one in which all field values are zero.
1916  *
1917  * \param object       A pointer to an existing CUESHEET object.
1918  * \param track_num    The index of the track to modify.  NOTE: this is not
1919  *                     necessarily the same as the track's \a number field.
1920  * \param index_num    The index into the track's index array at which to
1921  *                     insert the index point.  NOTE: this is not necessarily
1922  *                     the same as the index point's \a number field.  The
1923  *                     indices at and after \a index_num move right one
1924  *                     position.  To append an index point to the end, set
1925  *                     \a index_num to
1926  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
1927  * \assert
1928  *    \code object != NULL \endcode
1929  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1930  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1931  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
1932  * \retval FLAC__bool
1933  *    \c false if realloc() fails, else \c true.
1934  */
1935 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_blank_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
1936 
1937 /** Delete an index point in a CUESHEET track at the given index.
1938  *
1939  * \param object       A pointer to an existing CUESHEET object.
1940  * \param track_num    The index into the track array of the track to
1941  *                     modify.  NOTE: this is not necessarily the same
1942  *                     as the track's \a number field.
1943  * \param index_num    The index into the track's index array of the index
1944  *                     to delete.  NOTE: this is not necessarily the same
1945  *                     as the index's \a number field.
1946  * \assert
1947  *    \code object != NULL \endcode
1948  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1949  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1950  *    \code object->data.cue_sheet.tracks[track_num].num_indices > index_num \endcode
1951  * \retval FLAC__bool
1952  *    \c false if realloc() fails, else \c true.
1953  */
1954 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_delete_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
1955 
1956 /** Resize the track array.
1957  *
1958  *  If the size shrinks, elements will truncated; if it grows, new blank
1959  *  tracks will be added to the end.
1960  *
1961  * \param object            A pointer to an existing CUESHEET object.
1962  * \param new_num_tracks    The desired length of the array; may be \c 0.
1963  * \assert
1964  *    \code object != NULL \endcode
1965  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1966  *    \code (object->data.cue_sheet.tracks == NULL && object->data.cue_sheet.num_tracks == 0) ||
1967  * (object->data.cue_sheet.tracks != NULL && object->data.cue_sheet.num_tracks > 0) \endcode
1968  * \retval FLAC__bool
1969  *    \c false if memory allocation error, else \c true.
1970  */
1971 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_resize_tracks(FLAC__StreamMetadata *object, unsigned new_num_tracks);
1972 
1973 /** Sets a track in a CUESHEET block.
1974  *
1975  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
1976  *  takes ownership of the \a track pointer.
1977  *
1978  * \param object       A pointer to an existing CUESHEET object.
1979  * \param track_num    Index into track array to set.  NOTE: this is not
1980  *                     necessarily the same as the track's \a number field.
1981  * \param track        The track to set the track to.  You may safely pass in
1982  *                     a const pointer if \a copy is \c true.
1983  * \param copy         See above.
1984  * \assert
1985  *    \code object != NULL \endcode
1986  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1987  *    \code track_num < object->data.cue_sheet.num_tracks \endcode
1988  *    \code (track->indices != NULL && track->num_indices > 0) ||
1989  * (track->indices == NULL && track->num_indices == 0)
1990  * \retval FLAC__bool
1991  *    \c false if \a copy is \c true and malloc() fails, else \c true.
1992  */
1993 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_set_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
1994 
1995 /** Insert a track in a CUESHEET block at the given index.
1996  *
1997  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
1998  *  takes ownership of the \a track pointer.
1999  *
2000  * \param object       A pointer to an existing CUESHEET object.
2001  * \param track_num    The index at which to insert the track.  NOTE: this
2002  *                     is not necessarily the same as the track's \a number
2003  *                     field.  The tracks at and after \a track_num move right
2004  *                     one position.  To append a track to the end, set
2005  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
2006  * \param track        The track to insert.  You may safely pass in a const
2007  *                     pointer if \a copy is \c true.
2008  * \param copy         See above.
2009  * \assert
2010  *    \code object != NULL \endcode
2011  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2012  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
2013  * \retval FLAC__bool
2014  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2015  */
2016 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
2017 
2018 /** Insert a blank track in a CUESHEET block at the given index.
2019  *
2020  *  A blank track is one in which all field values are zero.
2021  *
2022  * \param object       A pointer to an existing CUESHEET object.
2023  * \param track_num    The index at which to insert the track.  NOTE: this
2024  *                     is not necessarily the same as the track's \a number
2025  *                     field.  The tracks at and after \a track_num move right
2026  *                     one position.  To append a track to the end, set
2027  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
2028  * \assert
2029  *    \code object != NULL \endcode
2030  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2031  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
2032  * \retval FLAC__bool
2033  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2034  */
2035 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_blank_track(FLAC__StreamMetadata *object, unsigned track_num);
2036 
2037 /** Delete a track in a CUESHEET block at the given index.
2038  *
2039  * \param object       A pointer to an existing CUESHEET object.
2040  * \param track_num    The index into the track array of the track to
2041  *                     delete.  NOTE: this is not necessarily the same
2042  *                     as the track's \a number field.
2043  * \assert
2044  *    \code object != NULL \endcode
2045  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2046  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
2047  * \retval FLAC__bool
2048  *    \c false if realloc() fails, else \c true.
2049  */
2050 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_delete_track(FLAC__StreamMetadata *object, unsigned track_num);
2051 
2052 /** Check a cue sheet to see if it conforms to the FLAC specification.
2053  *  See the format specification for limits on the contents of the
2054  *  cue sheet.
2055  *
2056  * \param object     A pointer to an existing CUESHEET object.
2057  * \param check_cd_da_subset  If \c true, check CUESHEET against more
2058  *                   stringent requirements for a CD-DA (audio) disc.
2059  * \param violation  Address of a pointer to a string.  If there is a
2060  *                   violation, a pointer to a string explanation of the
2061  *                   violation will be returned here. \a violation may be
2062  *                   \c NULL if you don't need the returned string.  Do not
2063  *                   free the returned string; it will always point to static
2064  *                   data.
2065  * \assert
2066  *    \code object != NULL \endcode
2067  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2068  * \retval FLAC__bool
2069  *    \c false if cue sheet is illegal, else \c true.
2070  */
2071 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_is_legal(const FLAC__StreamMetadata *object, FLAC__bool check_cd_da_subset, const char **violation);
2072 
2073 /** Calculate and return the CDDB/freedb ID for a cue sheet.  The function
2074  *  assumes the cue sheet corresponds to a CD; the result is undefined
2075  *  if the cuesheet's is_cd bit is not set.
2076  *
2077  * \param object     A pointer to an existing CUESHEET object.
2078  * \assert
2079  *    \code object != NULL \endcode
2080  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2081  * \retval FLAC__uint32
2082  *    The unsigned integer representation of the CDDB/freedb ID
2083  */
2084 FLAC_API FLAC__uint32 FLAC__metadata_object_cuesheet_calculate_cddb_id(const FLAC__StreamMetadata *object);
2085 
2086 /** Sets the MIME type of a PICTURE block.
2087  *
2088  *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
2089  *  takes ownership of the pointer.  The existing string will be freed if this
2090  *  function is successful, otherwise the original string will remain if \a copy
2091  *  is \c true and malloc() fails.
2092  *
2093  * \note It is safe to pass a const pointer to \a mime_type if \a copy is \c true.
2094  *
2095  * \param object      A pointer to an existing PICTURE object.
2096  * \param mime_type   A pointer to the MIME type string.  The string must be
2097  *                    ASCII characters 0x20-0x7e, NUL-terminated.  No validation
2098  *                    is done.
2099  * \param copy        See above.
2100  * \assert
2101  *    \code object != NULL \endcode
2102  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2103  *    \code (mime_type != NULL) \endcode
2104  * \retval FLAC__bool
2105  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2106  */
2107 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_mime_type(FLAC__StreamMetadata *object, char *mime_type, FLAC__bool copy);
2108 
2109 /** Sets the description of a PICTURE block.
2110  *
2111  *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
2112  *  takes ownership of the pointer.  The existing string will be freed if this
2113  *  function is successful, otherwise the original string will remain if \a copy
2114  *  is \c true and malloc() fails.
2115  *
2116  * \note It is safe to pass a const pointer to \a description if \a copy is \c true.
2117  *
2118  * \param object      A pointer to an existing PICTURE object.
2119  * \param description A pointer to the description string.  The string must be
2120  *                    valid UTF-8, NUL-terminated.  No validation is done.
2121  * \param copy        See above.
2122  * \assert
2123  *    \code object != NULL \endcode
2124  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2125  *    \code (description != NULL) \endcode
2126  * \retval FLAC__bool
2127  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2128  */
2129 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_description(FLAC__StreamMetadata *object, FLAC__byte *description, FLAC__bool copy);
2130 
2131 /** Sets the picture data of a PICTURE block.
2132  *
2133  *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
2134  *  takes ownership of the pointer.  Also sets the \a data_length field of the
2135  *  metadata object to what is passed in as the \a length parameter.  The
2136  *  existing data will be freed if this function is successful, otherwise the
2137  *  original data and data_length will remain if \a copy is \c true and
2138  *  malloc() fails.
2139  *
2140  * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
2141  *
2142  * \param object  A pointer to an existing PICTURE object.
2143  * \param data    A pointer to the data to set.
2144  * \param length  The length of \a data in bytes.
2145  * \param copy    See above.
2146  * \assert
2147  *    \code object != NULL \endcode
2148  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2149  *    \code (data != NULL && length > 0) ||
2150  * (data == NULL && length == 0 && copy == false) \endcode
2151  * \retval FLAC__bool
2152  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2153  */
2154 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, FLAC__uint32 length, FLAC__bool copy);
2155 
2156 /** Check a PICTURE block to see if it conforms to the FLAC specification.
2157  *  See the format specification for limits on the contents of the
2158  *  PICTURE block.
2159  *
2160  * \param object     A pointer to existing PICTURE block to be checked.
2161  * \param violation  Address of a pointer to a string.  If there is a
2162  *                   violation, a pointer to a string explanation of the
2163  *                   violation will be returned here. \a violation may be
2164  *                   \c NULL if you don't need the returned string.  Do not
2165  *                   free the returned string; it will always point to static
2166  *                   data.
2167  * \assert
2168  *    \code object != NULL \endcode
2169  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2170  * \retval FLAC__bool
2171  *    \c false if PICTURE block is illegal, else \c true.
2172  */
2173 FLAC_API FLAC__bool FLAC__metadata_object_picture_is_legal(const FLAC__StreamMetadata *object, const char **violation);
2174 
2175 /* \} */
2176 
2177 #ifdef __cplusplus
2178 }
2179 #endif
2180 
2181 #endif
2182