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1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2001-2009  Josh Coalson
3  * Copyright (C) 2011-2016  Xiph.Org Foundation
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * - Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *
12  * - Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in the
14  * documentation and/or other materials provided with the distribution.
15  *
16  * - Neither the name of the Xiph.org Foundation nor the names of its
17  * contributors may be used to endorse or promote products derived from
18  * this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifndef FLAC__METADATA_H
34 #define FLAC__METADATA_H
35 
36 #include <sys/types.h> /* for off_t */
37 #include "export.h"
38 #include "callback.h"
39 #include "format.h"
40 
41 /* --------------------------------------------------------------------
42    (For an example of how all these routines are used, see the source
43    code for the unit tests in src/test_libFLAC/metadata_*.c, or
44    metaflac in src/metaflac/)
45    ------------------------------------------------------------------*/
46 
47 /** \file include/FLAC/metadata.h
48  *
49  *  \brief
50  *  This module provides functions for creating and manipulating FLAC
51  *  metadata blocks in memory, and three progressively more powerful
52  *  interfaces for traversing and editing metadata in FLAC files.
53  *
54  *  See the detailed documentation for each interface in the
55  *  \link flac_metadata metadata \endlink module.
56  */
57 
58 /** \defgroup flac_metadata FLAC/metadata.h: metadata interfaces
59  *  \ingroup flac
60  *
61  *  \brief
62  *  This module provides functions for creating and manipulating FLAC
63  *  metadata blocks in memory, and three progressively more powerful
64  *  interfaces for traversing and editing metadata in native FLAC files.
65  *  Note that currently only the Chain interface (level 2) supports Ogg
66  *  FLAC files, and it is read-only i.e. no writing back changed
67  *  metadata to file.
68  *
69  *  There are three metadata interfaces of increasing complexity:
70  *
71  *  Level 0:
72  *  Read-only access to the STREAMINFO, VORBIS_COMMENT, CUESHEET, and
73  *  PICTURE blocks.
74  *
75  *  Level 1:
76  *  Read-write access to all metadata blocks.  This level is write-
77  *  efficient in most cases (more on this below), and uses less memory
78  *  than level 2.
79  *
80  *  Level 2:
81  *  Read-write access to all metadata blocks.  This level is write-
82  *  efficient in all cases, but uses more memory since all metadata for
83  *  the whole file is read into memory and manipulated before writing
84  *  out again.
85  *
86  *  What do we mean by efficient?  Since FLAC metadata appears at the
87  *  beginning of the file, when writing metadata back to a FLAC file
88  *  it is possible to grow or shrink the metadata such that the entire
89  *  file must be rewritten.  However, if the size remains the same during
90  *  changes or PADDING blocks are utilized, only the metadata needs to be
91  *  overwritten, which is much faster.
92  *
93  *  Efficient means the whole file is rewritten at most one time, and only
94  *  when necessary.  Level 1 is not efficient only in the case that you
95  *  cause more than one metadata block to grow or shrink beyond what can
96  *  be accomodated by padding.  In this case you should probably use level
97  *  2, which allows you to edit all the metadata for a file in memory and
98  *  write it out all at once.
99  *
100  *  All levels know how to skip over and not disturb an ID3v2 tag at the
101  *  front of the file.
102  *
103  *  All levels access files via their filenames.  In addition, level 2
104  *  has additional alternative read and write functions that take an I/O
105  *  handle and callbacks, for situations where access by filename is not
106  *  possible.
107  *
108  *  In addition to the three interfaces, this module defines functions for
109  *  creating and manipulating various metadata objects in memory.  As we see
110  *  from the Format module, FLAC metadata blocks in memory are very primitive
111  *  structures for storing information in an efficient way.  Reading
112  *  information from the structures is easy but creating or modifying them
113  *  directly is more complex.  The metadata object routines here facilitate
114  *  this by taking care of the consistency and memory management drudgery.
115  *
116  *  Unless you will be using the level 1 or 2 interfaces to modify existing
117  *  metadata however, you will not probably not need these.
118  *
119  *  From a dependency standpoint, none of the encoders or decoders require
120  *  the metadata module.  This is so that embedded users can strip out the
121  *  metadata module from libFLAC to reduce the size and complexity.
122  */
123 
124 #ifdef __cplusplus
125 extern "C" {
126 #endif
127 
128 
129 /** \defgroup flac_metadata_level0 FLAC/metadata.h: metadata level 0 interface
130  *  \ingroup flac_metadata
131  *
132  *  \brief
133  *  The level 0 interface consists of individual routines to read the
134  *  STREAMINFO, VORBIS_COMMENT, CUESHEET, and PICTURE blocks, requiring
135  *  only a filename.
136  *
137  *  They try to skip any ID3v2 tag at the head of the file.
138  *
139  * \{
140  */
141 
142 /** Read the STREAMINFO metadata block of the given FLAC file.  This function
143  *  will try to skip any ID3v2 tag at the head of the file.
144  *
145  * \param filename    The path to the FLAC file to read.
146  * \param streaminfo  A pointer to space for the STREAMINFO block.  Since
147  *                    FLAC__StreamMetadata is a simple structure with no
148  *                    memory allocation involved, you pass the address of
149  *                    an existing structure.  It need not be initialized.
150  * \assert
151  *    \code filename != NULL \endcode
152  *    \code streaminfo != NULL \endcode
153  * \retval FLAC__bool
154  *    \c true if a valid STREAMINFO block was read from \a filename.  Returns
155  *    \c false if there was a memory allocation error, a file decoder error,
156  *    or the file contained no STREAMINFO block.  (A memory allocation error
157  *    is possible because this function must set up a file decoder.)
158  */
159 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo);
160 
161 /** Read the VORBIS_COMMENT metadata block of the given FLAC file.  This
162  *  function will try to skip any ID3v2 tag at the head of the file.
163  *
164  * \param filename    The path to the FLAC file to read.
165  * \param tags        The address where the returned pointer will be
166  *                    stored.  The \a tags object must be deleted by
167  *                    the caller using FLAC__metadata_object_delete().
168  * \assert
169  *    \code filename != NULL \endcode
170  *    \code tags != NULL \endcode
171  * \retval FLAC__bool
172  *    \c true if a valid VORBIS_COMMENT block was read from \a filename,
173  *    and \a *tags will be set to the address of the metadata structure.
174  *    Returns \c false if there was a memory allocation error, a file
175  *    decoder error, or the file contained no VORBIS_COMMENT block, and
176  *    \a *tags will be set to \c NULL.
177  */
178 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags);
179 
180 /** Read the CUESHEET metadata block of the given FLAC file.  This
181  *  function will try to skip any ID3v2 tag at the head of the file.
182  *
183  * \param filename    The path to the FLAC file to read.
184  * \param cuesheet    The address where the returned pointer will be
185  *                    stored.  The \a cuesheet object must be deleted by
186  *                    the caller using FLAC__metadata_object_delete().
187  * \assert
188  *    \code filename != NULL \endcode
189  *    \code cuesheet != NULL \endcode
190  * \retval FLAC__bool
191  *    \c true if a valid CUESHEET block was read from \a filename,
192  *    and \a *cuesheet will be set to the address of the metadata
193  *    structure.  Returns \c false if there was a memory allocation
194  *    error, a file decoder error, or the file contained no CUESHEET
195  *    block, and \a *cuesheet will be set to \c NULL.
196  */
197 FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet);
198 
199 /** Read a PICTURE metadata block of the given FLAC file.  This
200  *  function will try to skip any ID3v2 tag at the head of the file.
201  *  Since there can be more than one PICTURE block in a file, this
202  *  function takes a number of parameters that act as constraints to
203  *  the search.  The PICTURE block with the largest area matching all
204  *  the constraints will be returned, or \a *picture will be set to
205  *  \c NULL if there was no such block.
206  *
207  * \param filename    The path to the FLAC file to read.
208  * \param picture     The address where the returned pointer will be
209  *                    stored.  The \a picture object must be deleted by
210  *                    the caller using FLAC__metadata_object_delete().
211  * \param type        The desired picture type.  Use \c -1 to mean
212  *                    "any type".
213  * \param mime_type   The desired MIME type, e.g. "image/jpeg".  The
214  *                    string will be matched exactly.  Use \c NULL to
215  *                    mean "any MIME type".
216  * \param description The desired description.  The string will be
217  *                    matched exactly.  Use \c NULL to mean "any
218  *                    description".
219  * \param max_width   The maximum width in pixels desired.  Use
220  *                    \c (unsigned)(-1) to mean "any width".
221  * \param max_height  The maximum height in pixels desired.  Use
222  *                    \c (unsigned)(-1) to mean "any height".
223  * \param max_depth   The maximum color depth in bits-per-pixel desired.
224  *                    Use \c (unsigned)(-1) to mean "any depth".
225  * \param max_colors  The maximum number of colors desired.  Use
226  *                    \c (unsigned)(-1) to mean "any number of colors".
227  * \assert
228  *    \code filename != NULL \endcode
229  *    \code picture != NULL \endcode
230  * \retval FLAC__bool
231  *    \c true if a valid PICTURE block was read from \a filename,
232  *    and \a *picture will be set to the address of the metadata
233  *    structure.  Returns \c false if there was a memory allocation
234  *    error, a file decoder error, or the file contained no PICTURE
235  *    block, and \a *picture will be set to \c NULL.
236  */
237 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);
238 
239 /* \} */
240 
241 
242 /** \defgroup flac_metadata_level1 FLAC/metadata.h: metadata level 1 interface
243  *  \ingroup flac_metadata
244  *
245  * \brief
246  * The level 1 interface provides read-write access to FLAC file metadata and
247  * operates directly on the FLAC file.
248  *
249  * The general usage of this interface is:
250  *
251  * - Create an iterator using FLAC__metadata_simple_iterator_new()
252  * - Attach it to a file using FLAC__metadata_simple_iterator_init() and check
253  *   the exit code.  Call FLAC__metadata_simple_iterator_is_writable() to
254  *   see if the file is writable, or only read access is allowed.
255  * - Use FLAC__metadata_simple_iterator_next() and
256  *   FLAC__metadata_simple_iterator_prev() to traverse the blocks.
257  *   This is does not read the actual blocks themselves.
258  *   FLAC__metadata_simple_iterator_next() is relatively fast.
259  *   FLAC__metadata_simple_iterator_prev() is slower since it needs to search
260  *   forward from the front of the file.
261  * - Use FLAC__metadata_simple_iterator_get_block_type() or
262  *   FLAC__metadata_simple_iterator_get_block() to access the actual data at
263  *   the current iterator position.  The returned object is yours to modify
264  *   and free.
265  * - Use FLAC__metadata_simple_iterator_set_block() to write a modified block
266  *   back.  You must have write permission to the original file.  Make sure to
267  *   read the whole comment to FLAC__metadata_simple_iterator_set_block()
268  *   below.
269  * - Use FLAC__metadata_simple_iterator_insert_block_after() to add new blocks.
270  *   Use the object creation functions from
271  *   \link flac_metadata_object here \endlink to generate new objects.
272  * - Use FLAC__metadata_simple_iterator_delete_block() to remove the block
273  *   currently referred to by the iterator, or replace it with padding.
274  * - Destroy the iterator with FLAC__metadata_simple_iterator_delete() when
275  *   finished.
276  *
277  * \note
278  * The FLAC file remains open the whole time between
279  * FLAC__metadata_simple_iterator_init() and
280  * FLAC__metadata_simple_iterator_delete(), so make sure you are not altering
281  * the file during this time.
282  *
283  * \note
284  * Do not modify the \a is_last, \a length, or \a type fields of returned
285  * FLAC__StreamMetadata objects.  These are managed automatically.
286  *
287  * \note
288  * If any of the modification functions
289  * (FLAC__metadata_simple_iterator_set_block(),
290  * FLAC__metadata_simple_iterator_delete_block(),
291  * FLAC__metadata_simple_iterator_insert_block_after(), etc.) return \c false,
292  * you should delete the iterator as it may no longer be valid.
293  *
294  * \{
295  */
296 
297 struct FLAC__Metadata_SimpleIterator;
298 /** The opaque structure definition for the level 1 iterator type.
299  *  See the
300  *  \link flac_metadata_level1 metadata level 1 module \endlink
301  *  for a detailed description.
302  */
303 typedef struct FLAC__Metadata_SimpleIterator FLAC__Metadata_SimpleIterator;
304 
305 /** Status type for FLAC__Metadata_SimpleIterator.
306  *
307  *  The iterator's current status can be obtained by calling FLAC__metadata_simple_iterator_status().
308  */
309 typedef enum {
310 
311 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK = 0,
312 	/**< The iterator is in the normal OK state */
313 
314 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT,
315 	/**< The data passed into a function violated the function's usage criteria */
316 
317 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE,
318 	/**< The iterator could not open the target file */
319 
320 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE,
321 	/**< The iterator could not find the FLAC signature at the start of the file */
322 
323 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE,
324 	/**< The iterator tried to write to a file that was not writable */
325 
326 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA,
327 	/**< The iterator encountered input that does not conform to the FLAC metadata specification */
328 
329 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR,
330 	/**< The iterator encountered an error while reading the FLAC file */
331 
332 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR,
333 	/**< The iterator encountered an error while seeking in the FLAC file */
334 
335 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR,
336 	/**< The iterator encountered an error while writing the FLAC file */
337 
338 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR,
339 	/**< The iterator encountered an error renaming the FLAC file */
340 
341 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR,
342 	/**< The iterator encountered an error removing the temporary file */
343 
344 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR,
345 	/**< Memory allocation failed */
346 
347 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR
348 	/**< The caller violated an assertion or an unexpected error occurred */
349 
350 } FLAC__Metadata_SimpleIteratorStatus;
351 
352 /** Maps a FLAC__Metadata_SimpleIteratorStatus to a C string.
353  *
354  *  Using a FLAC__Metadata_SimpleIteratorStatus as the index to this array
355  *  will give the string equivalent.  The contents should not be modified.
356  */
357 extern FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[];
358 
359 
360 /** Create a new iterator instance.
361  *
362  * \retval FLAC__Metadata_SimpleIterator*
363  *    \c NULL if there was an error allocating memory, else the new instance.
364  */
365 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new(void);
366 
367 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
368  *
369  * \param iterator  A pointer to an existing iterator.
370  * \assert
371  *    \code iterator != NULL \endcode
372  */
373 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator);
374 
375 /** Get the current status of the iterator.  Call this after a function
376  *  returns \c false to get the reason for the error.  Also resets the status
377  *  to FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK.
378  *
379  * \param iterator  A pointer to an existing iterator.
380  * \assert
381  *    \code iterator != NULL \endcode
382  * \retval FLAC__Metadata_SimpleIteratorStatus
383  *    The current status of the iterator.
384  */
385 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator);
386 
387 /** Initialize the iterator to point to the first metadata block in the
388  *  given FLAC file.
389  *
390  * \param iterator             A pointer to an existing iterator.
391  * \param filename             The path to the FLAC file.
392  * \param read_only            If \c true, the FLAC file will be opened
393  *                             in read-only mode; if \c false, the FLAC
394  *                             file will be opened for edit even if no
395  *                             edits are performed.
396  * \param preserve_file_stats  If \c true, the owner and modification
397  *                             time will be preserved even if the FLAC
398  *                             file is written to.
399  * \assert
400  *    \code iterator != NULL \endcode
401  *    \code filename != NULL \endcode
402  * \retval FLAC__bool
403  *    \c false if a memory allocation error occurs, the file can't be
404  *    opened, or another error occurs, else \c true.
405  */
406 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);
407 
408 /** Returns \c true if the FLAC file is writable.  If \c false, calls to
409  *  FLAC__metadata_simple_iterator_set_block() and
410  *  FLAC__metadata_simple_iterator_insert_block_after() will fail.
411  *
412  * \param iterator             A pointer to an existing iterator.
413  * \assert
414  *    \code iterator != NULL \endcode
415  * \retval FLAC__bool
416  *    See above.
417  */
418 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator);
419 
420 /** Moves the iterator forward one metadata block, returning \c false if
421  *  already at the end.
422  *
423  * \param iterator  A pointer to an existing initialized iterator.
424  * \assert
425  *    \code iterator != NULL \endcode
426  *    \a iterator has been successfully initialized with
427  *    FLAC__metadata_simple_iterator_init()
428  * \retval FLAC__bool
429  *    \c false if already at the last metadata block of the chain, else
430  *    \c true.
431  */
432 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator);
433 
434 /** Moves the iterator backward one metadata block, returning \c false if
435  *  already at the beginning.
436  *
437  * \param iterator  A pointer to an existing initialized iterator.
438  * \assert
439  *    \code iterator != NULL \endcode
440  *    \a iterator has been successfully initialized with
441  *    FLAC__metadata_simple_iterator_init()
442  * \retval FLAC__bool
443  *    \c false if already at the first metadata block of the chain, else
444  *    \c true.
445  */
446 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator);
447 
448 /** Returns a flag telling if the current metadata block is the last.
449  *
450  * \param iterator  A pointer to an existing initialized iterator.
451  * \assert
452  *    \code iterator != NULL \endcode
453  *    \a iterator has been successfully initialized with
454  *    FLAC__metadata_simple_iterator_init()
455  * \retval FLAC__bool
456  *    \c true if the current metadata block is the last in the file,
457  *    else \c false.
458  */
459 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator);
460 
461 /** Get the offset of the metadata block at the current position.  This
462  *  avoids reading the actual block data which can save time for large
463  *  blocks.
464  *
465  * \param iterator  A pointer to an existing initialized iterator.
466  * \assert
467  *    \code iterator != NULL \endcode
468  *    \a iterator has been successfully initialized with
469  *    FLAC__metadata_simple_iterator_init()
470  * \retval off_t
471  *    The offset of the metadata block at the current iterator position.
472  *    This is the byte offset relative to the beginning of the file of
473  *    the current metadata block's header.
474  */
475 FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const FLAC__Metadata_SimpleIterator *iterator);
476 
477 /** Get the type of the metadata block at the current position.  This
478  *  avoids reading the actual block data which can save time for large
479  *  blocks.
480  *
481  * \param iterator  A pointer to an existing initialized iterator.
482  * \assert
483  *    \code iterator != NULL \endcode
484  *    \a iterator has been successfully initialized with
485  *    FLAC__metadata_simple_iterator_init()
486  * \retval FLAC__MetadataType
487  *    The type of the metadata block at the current iterator position.
488  */
489 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator);
490 
491 /** Get the length of the metadata block at the current position.  This
492  *  avoids reading the actual block data which can save time for large
493  *  blocks.
494  *
495  * \param iterator  A pointer to an existing initialized iterator.
496  * \assert
497  *    \code iterator != NULL \endcode
498  *    \a iterator has been successfully initialized with
499  *    FLAC__metadata_simple_iterator_init()
500  * \retval unsigned
501  *    The length of the metadata block at the current iterator position.
502  *    The is same length as that in the
503  *    <a href="http://xiph.org/flac/format.html#metadata_block_header">metadata block header</a>,
504  *    i.e. the length of the metadata body that follows the header.
505  */
506 FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator);
507 
508 /** Get the application ID of the \c APPLICATION block at the current
509  *  position.  This avoids reading the actual block data which can save
510  *  time for large blocks.
511  *
512  * \param iterator  A pointer to an existing initialized iterator.
513  * \param id        A pointer to a buffer of at least \c 4 bytes where
514  *                  the ID will be stored.
515  * \assert
516  *    \code iterator != NULL \endcode
517  *    \code id != NULL \endcode
518  *    \a iterator has been successfully initialized with
519  *    FLAC__metadata_simple_iterator_init()
520  * \retval FLAC__bool
521  *    \c true if the ID was successfully read, else \c false, in which
522  *    case you should check FLAC__metadata_simple_iterator_status() to
523  *    find out why.  If the status is
524  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT, then the
525  *    current metadata block is not an \c APPLICATION block.  Otherwise
526  *    if the status is
527  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR or
528  *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR, an I/O error
529  *    occurred and the iterator can no longer be used.
530  */
531 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id);
532 
533 /** Get the metadata block at the current position.  You can modify the
534  *  block but must use FLAC__metadata_simple_iterator_set_block() to
535  *  write it back to the FLAC file.
536  *
537  *  You must call FLAC__metadata_object_delete() on the returned object
538  *  when you are finished with it.
539  *
540  * \param iterator  A pointer to an existing initialized iterator.
541  * \assert
542  *    \code iterator != NULL \endcode
543  *    \a iterator has been successfully initialized with
544  *    FLAC__metadata_simple_iterator_init()
545  * \retval FLAC__StreamMetadata*
546  *    The current metadata block, or \c NULL if there was a memory
547  *    allocation error.
548  */
549 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator);
550 
551 /** Write a block back to the FLAC file.  This function tries to be
552  *  as efficient as possible; how the block is actually written is
553  *  shown by the following:
554  *
555  *  Existing block is a STREAMINFO block and the new block is a
556  *  STREAMINFO block: the new block is written in place.  Make sure
557  *  you know what you're doing when changing the values of a
558  *  STREAMINFO block.
559  *
560  *  Existing block is a STREAMINFO block and the new block is a
561  *  not a STREAMINFO block: this is an error since the first block
562  *  must be a STREAMINFO block.  Returns \c false without altering the
563  *  file.
564  *
565  *  Existing block is not a STREAMINFO block and the new block is a
566  *  STREAMINFO block: this is an error since there may be only one
567  *  STREAMINFO block.  Returns \c false without altering the file.
568  *
569  *  Existing block and new block are the same length: the existing
570  *  block will be replaced by the new block, written in place.
571  *
572  *  Existing block is longer than new block: if use_padding is \c true,
573  *  the existing block will be overwritten in place with the new
574  *  block followed by a PADDING block, if possible, to make the total
575  *  size the same as the existing block.  Remember that a padding
576  *  block requires at least four bytes so if the difference in size
577  *  between the new block and existing block is less than that, the
578  *  entire file will have to be rewritten, using the new block's
579  *  exact size.  If use_padding is \c false, the entire file will be
580  *  rewritten, replacing the existing block by the new block.
581  *
582  *  Existing block is shorter than new block: if use_padding is \c true,
583  *  the function will try and expand the new block into the following
584  *  PADDING block, if it exists and doing so won't shrink the PADDING
585  *  block to less than 4 bytes.  If there is no following PADDING
586  *  block, or it will shrink to less than 4 bytes, or use_padding is
587  *  \c false, the entire file is rewritten, replacing the existing block
588  *  with the new block.  Note that in this case any following PADDING
589  *  block is preserved as is.
590  *
591  *  After writing the block, the iterator will remain in the same
592  *  place, i.e. pointing to the new block.
593  *
594  * \param iterator     A pointer to an existing initialized iterator.
595  * \param block        The block to set.
596  * \param use_padding  See above.
597  * \assert
598  *    \code iterator != NULL \endcode
599  *    \a iterator has been successfully initialized with
600  *    FLAC__metadata_simple_iterator_init()
601  *    \code block != NULL \endcode
602  * \retval FLAC__bool
603  *    \c true if successful, else \c false.
604  */
605 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
606 
607 /** This is similar to FLAC__metadata_simple_iterator_set_block()
608  *  except that instead of writing over an existing block, it appends
609  *  a block after the existing block.  \a use_padding is again used to
610  *  tell the function to try an expand into following padding in an
611  *  attempt to avoid rewriting the entire file.
612  *
613  *  This function will fail and return \c false if given a STREAMINFO
614  *  block.
615  *
616  *  After writing the block, the iterator will be pointing to the
617  *  new block.
618  *
619  * \param iterator     A pointer to an existing initialized iterator.
620  * \param block        The block to set.
621  * \param use_padding  See above.
622  * \assert
623  *    \code iterator != NULL \endcode
624  *    \a iterator has been successfully initialized with
625  *    FLAC__metadata_simple_iterator_init()
626  *    \code block != NULL \endcode
627  * \retval FLAC__bool
628  *    \c true if successful, else \c false.
629  */
630 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
631 
632 /** Deletes the block at the current position.  This will cause the
633  *  entire FLAC file to be rewritten, unless \a use_padding is \c true,
634  *  in which case the block will be replaced by an equal-sized PADDING
635  *  block.  The iterator will be left pointing to the block before the
636  *  one just deleted.
637  *
638  *  You may not delete the STREAMINFO block.
639  *
640  * \param iterator     A pointer to an existing initialized iterator.
641  * \param use_padding  See above.
642  * \assert
643  *    \code iterator != NULL \endcode
644  *    \a iterator has been successfully initialized with
645  *    FLAC__metadata_simple_iterator_init()
646  * \retval FLAC__bool
647  *    \c true if successful, else \c false.
648  */
649 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding);
650 
651 /* \} */
652 
653 
654 /** \defgroup flac_metadata_level2 FLAC/metadata.h: metadata level 2 interface
655  *  \ingroup flac_metadata
656  *
657  * \brief
658  * The level 2 interface provides read-write access to FLAC file metadata;
659  * all metadata is read into memory, operated on in memory, and then written
660  * to file, which is more efficient than level 1 when editing multiple blocks.
661  *
662  * Currently Ogg FLAC is supported for read only, via
663  * FLAC__metadata_chain_read_ogg() but a subsequent
664  * FLAC__metadata_chain_write() will fail.
665  *
666  * The general usage of this interface is:
667  *
668  * - Create a new chain using FLAC__metadata_chain_new().  A chain is a
669  *   linked list of FLAC metadata blocks.
670  * - Read all metadata into the chain from a FLAC file using
671  *   FLAC__metadata_chain_read() or FLAC__metadata_chain_read_ogg() and
672  *   check the status.
673  * - Optionally, consolidate the padding using
674  *   FLAC__metadata_chain_merge_padding() or
675  *   FLAC__metadata_chain_sort_padding().
676  * - Create a new iterator using FLAC__metadata_iterator_new()
677  * - Initialize the iterator to point to the first element in the chain
678  *   using FLAC__metadata_iterator_init()
679  * - Traverse the chain using FLAC__metadata_iterator_next and
680  *   FLAC__metadata_iterator_prev().
681  * - Get a block for reading or modification using
682  *   FLAC__metadata_iterator_get_block().  The pointer to the object
683  *   inside the chain is returned, so the block is yours to modify.
684  *   Changes will be reflected in the FLAC file when you write the
685  *   chain.  You can also add and delete blocks (see functions below).
686  * - When done, write out the chain using FLAC__metadata_chain_write().
687  *   Make sure to read the whole comment to the function below.
688  * - Delete the chain using FLAC__metadata_chain_delete().
689  *
690  * \note
691  * Even though the FLAC file is not open while the chain is being
692  * manipulated, you must not alter the file externally during
693  * this time.  The chain assumes the FLAC file will not change
694  * between the time of FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg()
695  * and FLAC__metadata_chain_write().
696  *
697  * \note
698  * Do not modify the is_last, length, or type fields of returned
699  * FLAC__StreamMetadata objects.  These are managed automatically.
700  *
701  * \note
702  * The metadata objects returned by FLAC__metadata_iterator_get_block()
703  * are owned by the chain; do not FLAC__metadata_object_delete() them.
704  * In the same way, blocks passed to FLAC__metadata_iterator_set_block()
705  * become owned by the chain and they will be deleted when the chain is
706  * deleted.
707  *
708  * \{
709  */
710 
711 struct FLAC__Metadata_Chain;
712 /** The opaque structure definition for the level 2 chain type.
713  */
714 typedef struct FLAC__Metadata_Chain FLAC__Metadata_Chain;
715 
716 struct FLAC__Metadata_Iterator;
717 /** The opaque structure definition for the level 2 iterator type.
718  */
719 typedef struct FLAC__Metadata_Iterator FLAC__Metadata_Iterator;
720 
721 typedef enum {
722 	FLAC__METADATA_CHAIN_STATUS_OK = 0,
723 	/**< The chain is in the normal OK state */
724 
725 	FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT,
726 	/**< The data passed into a function violated the function's usage criteria */
727 
728 	FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE,
729 	/**< The chain could not open the target file */
730 
731 	FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE,
732 	/**< The chain could not find the FLAC signature at the start of the file */
733 
734 	FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE,
735 	/**< The chain tried to write to a file that was not writable */
736 
737 	FLAC__METADATA_CHAIN_STATUS_BAD_METADATA,
738 	/**< The chain encountered input that does not conform to the FLAC metadata specification */
739 
740 	FLAC__METADATA_CHAIN_STATUS_READ_ERROR,
741 	/**< The chain encountered an error while reading the FLAC file */
742 
743 	FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR,
744 	/**< The chain encountered an error while seeking in the FLAC file */
745 
746 	FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR,
747 	/**< The chain encountered an error while writing the FLAC file */
748 
749 	FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR,
750 	/**< The chain encountered an error renaming the FLAC file */
751 
752 	FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR,
753 	/**< The chain encountered an error removing the temporary file */
754 
755 	FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR,
756 	/**< Memory allocation failed */
757 
758 	FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR,
759 	/**< The caller violated an assertion or an unexpected error occurred */
760 
761 	FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS,
762 	/**< One or more of the required callbacks was NULL */
763 
764 	FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH,
765 	/**< FLAC__metadata_chain_write() was called on a chain read by
766 	 *   FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
767 	 *   or
768 	 *   FLAC__metadata_chain_write_with_callbacks()/FLAC__metadata_chain_write_with_callbacks_and_tempfile()
769 	 *   was called on a chain read by
770 	 *   FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
771 	 *   Matching read/write methods must always be used. */
772 
773 	FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL
774 	/**< FLAC__metadata_chain_write_with_callbacks() was called when the
775 	 *   chain write requires a tempfile; use
776 	 *   FLAC__metadata_chain_write_with_callbacks_and_tempfile() instead.
777 	 *   Or, FLAC__metadata_chain_write_with_callbacks_and_tempfile() was
778 	 *   called when the chain write does not require a tempfile; use
779 	 *   FLAC__metadata_chain_write_with_callbacks() instead.
780 	 *   Always check FLAC__metadata_chain_check_if_tempfile_needed()
781 	 *   before writing via callbacks. */
782 
783 } FLAC__Metadata_ChainStatus;
784 
785 /** Maps a FLAC__Metadata_ChainStatus to a C string.
786  *
787  *  Using a FLAC__Metadata_ChainStatus as the index to this array
788  *  will give the string equivalent.  The contents should not be modified.
789  */
790 extern FLAC_API const char * const FLAC__Metadata_ChainStatusString[];
791 
792 /*********** FLAC__Metadata_Chain ***********/
793 
794 /** Create a new chain instance.
795  *
796  * \retval FLAC__Metadata_Chain*
797  *    \c NULL if there was an error allocating memory, else the new instance.
798  */
799 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new(void);
800 
801 /** Free a chain instance.  Deletes the object pointed to by \a chain.
802  *
803  * \param chain  A pointer to an existing chain.
804  * \assert
805  *    \code chain != NULL \endcode
806  */
807 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain);
808 
809 /** Get the current status of the chain.  Call this after a function
810  *  returns \c false to get the reason for the error.  Also resets the
811  *  status to FLAC__METADATA_CHAIN_STATUS_OK.
812  *
813  * \param chain    A pointer to an existing chain.
814  * \assert
815  *    \code chain != NULL \endcode
816  * \retval FLAC__Metadata_ChainStatus
817  *    The current status of the chain.
818  */
819 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain);
820 
821 /** Read all metadata from a FLAC file into the chain.
822  *
823  * \param chain    A pointer to an existing chain.
824  * \param filename The path to the FLAC file to read.
825  * \assert
826  *    \code chain != NULL \endcode
827  *    \code filename != NULL \endcode
828  * \retval FLAC__bool
829  *    \c true if a valid list of metadata blocks was read from
830  *    \a filename, else \c false.  On failure, check the status with
831  *    FLAC__metadata_chain_status().
832  */
833 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename);
834 
835 /** Read all metadata from an Ogg FLAC file into the chain.
836  *
837  * \note Ogg FLAC metadata data writing is not supported yet and
838  * FLAC__metadata_chain_write() will fail.
839  *
840  * \param chain    A pointer to an existing chain.
841  * \param filename The path to the Ogg FLAC file to read.
842  * \assert
843  *    \code chain != NULL \endcode
844  *    \code filename != NULL \endcode
845  * \retval FLAC__bool
846  *    \c true if a valid list of metadata blocks was read from
847  *    \a filename, else \c false.  On failure, check the status with
848  *    FLAC__metadata_chain_status().
849  */
850 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg(FLAC__Metadata_Chain *chain, const char *filename);
851 
852 /** Read all metadata from a FLAC stream into the chain via I/O callbacks.
853  *
854  *  The \a handle need only be open for reading, but must be seekable.
855  *  The equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
856  *  for Windows).
857  *
858  * \param chain    A pointer to an existing chain.
859  * \param handle   The I/O handle of the FLAC stream to read.  The
860  *                 handle will NOT be closed after the metadata is read;
861  *                 that is the duty of the caller.
862  * \param callbacks
863  *                 A set of callbacks to use for I/O.  The mandatory
864  *                 callbacks are \a read, \a seek, and \a tell.
865  * \assert
866  *    \code chain != NULL \endcode
867  * \retval FLAC__bool
868  *    \c true if a valid list of metadata blocks was read from
869  *    \a handle, else \c false.  On failure, check the status with
870  *    FLAC__metadata_chain_status().
871  */
872 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
873 
874 /** Read all metadata from an Ogg FLAC stream into the chain via I/O callbacks.
875  *
876  *  The \a handle need only be open for reading, but must be seekable.
877  *  The equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
878  *  for Windows).
879  *
880  * \note Ogg FLAC metadata data writing is not supported yet and
881  * FLAC__metadata_chain_write() will fail.
882  *
883  * \param chain    A pointer to an existing chain.
884  * \param handle   The I/O handle of the Ogg FLAC stream to read.  The
885  *                 handle will NOT be closed after the metadata is read;
886  *                 that is the duty of the caller.
887  * \param callbacks
888  *                 A set of callbacks to use for I/O.  The mandatory
889  *                 callbacks are \a read, \a seek, and \a tell.
890  * \assert
891  *    \code chain != NULL \endcode
892  * \retval FLAC__bool
893  *    \c true if a valid list of metadata blocks was read from
894  *    \a handle, else \c false.  On failure, check the status with
895  *    FLAC__metadata_chain_status().
896  */
897 FLAC_API FLAC__bool FLAC__metadata_chain_read_ogg_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
898 
899 /** Checks if writing the given chain would require the use of a
900  *  temporary file, or if it could be written in place.
901  *
902  *  Under certain conditions, padding can be utilized so that writing
903  *  edited metadata back to the FLAC file does not require rewriting the
904  *  entire file.  If rewriting is required, then a temporary workfile is
905  *  required.  When writing metadata using callbacks, you must check
906  *  this function to know whether to call
907  *  FLAC__metadata_chain_write_with_callbacks() or
908  *  FLAC__metadata_chain_write_with_callbacks_and_tempfile().  When
909  *  writing with FLAC__metadata_chain_write(), the temporary file is
910  *  handled internally.
911  *
912  * \param chain    A pointer to an existing chain.
913  * \param use_padding
914  *                 Whether or not padding will be allowed to be used
915  *                 during the write.  The value of \a use_padding given
916  *                 here must match the value later passed to
917  *                 FLAC__metadata_chain_write_with_callbacks() or
918  *                 FLAC__metadata_chain_write_with_callbacks_with_tempfile().
919  * \assert
920  *    \code chain != NULL \endcode
921  * \retval FLAC__bool
922  *    \c true if writing the current chain would require a tempfile, or
923  *    \c false if metadata can be written in place.
924  */
925 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding);
926 
927 /** Write all metadata out to the FLAC file.  This function tries to be as
928  *  efficient as possible; how the metadata is actually written is shown by
929  *  the following:
930  *
931  *  If the current chain is the same size as the existing metadata, the new
932  *  data is written in place.
933  *
934  *  If the current chain is longer than the existing metadata, and
935  *  \a use_padding is \c true, and the last block is a PADDING block of
936  *  sufficient length, the function will truncate the final padding block
937  *  so that the overall size of the metadata is the same as the existing
938  *  metadata, and then just rewrite the metadata.  Otherwise, if not all of
939  *  the above conditions are met, the entire FLAC file must be rewritten.
940  *  If you want to use padding this way it is a good idea to call
941  *  FLAC__metadata_chain_sort_padding() first so that you have the maximum
942  *  amount of padding to work with, unless you need to preserve ordering
943  *  of the PADDING blocks for some reason.
944  *
945  *  If the current chain is shorter than the existing metadata, and
946  *  \a use_padding is \c true, and the final block is a PADDING block, the padding
947  *  is extended to make the overall size the same as the existing data.  If
948  *  \a use_padding is \c true and the last block is not a PADDING block, a new
949  *  PADDING block is added to the end of the new data to make it the same
950  *  size as the existing data (if possible, see the note to
951  *  FLAC__metadata_simple_iterator_set_block() about the four byte limit)
952  *  and the new data is written in place.  If none of the above apply or
953  *  \a use_padding is \c false, the entire FLAC file is rewritten.
954  *
955  *  If \a preserve_file_stats is \c true, the owner and modification time will
956  *  be preserved even if the FLAC file is written.
957  *
958  *  For this write function to be used, the chain must have been read with
959  *  FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg(), not
960  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks().
961  *
962  * \param chain               A pointer to an existing chain.
963  * \param use_padding         See above.
964  * \param preserve_file_stats See above.
965  * \assert
966  *    \code chain != NULL \endcode
967  * \retval FLAC__bool
968  *    \c true if the write succeeded, else \c false.  On failure,
969  *    check the status with FLAC__metadata_chain_status().
970  */
971 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats);
972 
973 /** Write all metadata out to a FLAC stream via callbacks.
974  *
975  *  (See FLAC__metadata_chain_write() for the details on how padding is
976  *  used to write metadata in place if possible.)
977  *
978  *  The \a handle must be open for updating and be seekable.  The
979  *  equivalent minimum stdio fopen() file mode is \c "r+" (or \c "r+b"
980  *  for Windows).
981  *
982  *  For this write function to be used, the chain must have been read with
983  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
984  *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
985  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
986  *  \c false.
987  *
988  * \param chain        A pointer to an existing chain.
989  * \param use_padding  See FLAC__metadata_chain_write()
990  * \param handle       The I/O handle of the FLAC stream to write.  The
991  *                     handle will NOT be closed after the metadata is
992  *                     written; that is the duty of the caller.
993  * \param callbacks    A set of callbacks to use for I/O.  The mandatory
994  *                     callbacks are \a write and \a seek.
995  * \assert
996  *    \code chain != NULL \endcode
997  * \retval FLAC__bool
998  *    \c true if the write succeeded, else \c false.  On failure,
999  *    check the status with FLAC__metadata_chain_status().
1000  */
1001 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
1002 
1003 /** Write all metadata out to a FLAC stream via callbacks.
1004  *
1005  *  (See FLAC__metadata_chain_write() for the details on how padding is
1006  *  used to write metadata in place if possible.)
1007  *
1008  *  This version of the write-with-callbacks function must be used when
1009  *  FLAC__metadata_chain_check_if_tempfile_needed() returns true.  In
1010  *  this function, you must supply an I/O handle corresponding to the
1011  *  FLAC file to edit, and a temporary handle to which the new FLAC
1012  *  file will be written.  It is the caller's job to move this temporary
1013  *  FLAC file on top of the original FLAC file to complete the metadata
1014  *  edit.
1015  *
1016  *  The \a handle must be open for reading and be seekable.  The
1017  *  equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
1018  *  for Windows).
1019  *
1020  *  The \a temp_handle must be open for writing.  The
1021  *  equivalent minimum stdio fopen() file mode is \c "w" (or \c "wb"
1022  *  for Windows).  It should be an empty stream, or at least positioned
1023  *  at the start-of-file (in which case it is the caller's duty to
1024  *  truncate it on return).
1025  *
1026  *  For this write function to be used, the chain must have been read with
1027  *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_with_callbacks(),
1028  *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
1029  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
1030  *  \c true.
1031  *
1032  * \param chain        A pointer to an existing chain.
1033  * \param use_padding  See FLAC__metadata_chain_write()
1034  * \param handle       The I/O handle of the original FLAC stream to read.
1035  *                     The handle will NOT be closed after the metadata is
1036  *                     written; that is the duty of the caller.
1037  * \param callbacks    A set of callbacks to use for I/O on \a handle.
1038  *                     The mandatory callbacks are \a read, \a seek, and
1039  *                     \a eof.
1040  * \param temp_handle  The I/O handle of the FLAC stream to write.  The
1041  *                     handle will NOT be closed after the metadata is
1042  *                     written; that is the duty of the caller.
1043  * \param temp_callbacks
1044  *                     A set of callbacks to use for I/O on temp_handle.
1045  *                     The only mandatory callback is \a write.
1046  * \assert
1047  *    \code chain != NULL \endcode
1048  * \retval FLAC__bool
1049  *    \c true if the write succeeded, else \c false.  On failure,
1050  *    check the status with FLAC__metadata_chain_status().
1051  */
1052 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);
1053 
1054 /** Merge adjacent PADDING blocks into a single block.
1055  *
1056  * \note This function does not write to the FLAC file, it only
1057  * modifies the chain.
1058  *
1059  * \warning Any iterator on the current chain will become invalid after this
1060  * call.  You should delete the iterator and get a new one.
1061  *
1062  * \param chain               A pointer to an existing chain.
1063  * \assert
1064  *    \code chain != NULL \endcode
1065  */
1066 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain);
1067 
1068 /** This function will move all PADDING blocks to the end on the metadata,
1069  *  then merge them into a single block.
1070  *
1071  * \note This function does not write to the FLAC file, it only
1072  * modifies the chain.
1073  *
1074  * \warning Any iterator on the current chain will become invalid after this
1075  * call.  You should delete the iterator and get a new one.
1076  *
1077  * \param chain  A pointer to an existing chain.
1078  * \assert
1079  *    \code chain != NULL \endcode
1080  */
1081 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain);
1082 
1083 
1084 /*********** FLAC__Metadata_Iterator ***********/
1085 
1086 /** Create a new iterator instance.
1087  *
1088  * \retval FLAC__Metadata_Iterator*
1089  *    \c NULL if there was an error allocating memory, else the new instance.
1090  */
1091 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new(void);
1092 
1093 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
1094  *
1095  * \param iterator  A pointer to an existing iterator.
1096  * \assert
1097  *    \code iterator != NULL \endcode
1098  */
1099 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator);
1100 
1101 /** Initialize the iterator to point to the first metadata block in the
1102  *  given chain.
1103  *
1104  * \param iterator  A pointer to an existing iterator.
1105  * \param chain     A pointer to an existing and initialized (read) chain.
1106  * \assert
1107  *    \code iterator != NULL \endcode
1108  *    \code chain != NULL \endcode
1109  */
1110 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain);
1111 
1112 /** Moves the iterator forward one metadata block, returning \c false if
1113  *  already at the end.
1114  *
1115  * \param iterator  A pointer to an existing initialized iterator.
1116  * \assert
1117  *    \code iterator != NULL \endcode
1118  *    \a iterator has been successfully initialized with
1119  *    FLAC__metadata_iterator_init()
1120  * \retval FLAC__bool
1121  *    \c false if already at the last metadata block of the chain, else
1122  *    \c true.
1123  */
1124 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator);
1125 
1126 /** Moves the iterator backward one metadata block, returning \c false if
1127  *  already at the beginning.
1128  *
1129  * \param iterator  A pointer to an existing initialized iterator.
1130  * \assert
1131  *    \code iterator != NULL \endcode
1132  *    \a iterator has been successfully initialized with
1133  *    FLAC__metadata_iterator_init()
1134  * \retval FLAC__bool
1135  *    \c false if already at the first metadata block of the chain, else
1136  *    \c true.
1137  */
1138 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator);
1139 
1140 /** Get the type of the metadata block at the current position.
1141  *
1142  * \param iterator  A pointer to an existing initialized iterator.
1143  * \assert
1144  *    \code iterator != NULL \endcode
1145  *    \a iterator has been successfully initialized with
1146  *    FLAC__metadata_iterator_init()
1147  * \retval FLAC__MetadataType
1148  *    The type of the metadata block at the current iterator position.
1149  */
1150 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator);
1151 
1152 /** Get the metadata block at the current position.  You can modify
1153  *  the block in place but must write the chain before the changes
1154  *  are reflected to the FLAC file.  You do not need to call
1155  *  FLAC__metadata_iterator_set_block() to reflect the changes;
1156  *  the pointer returned by FLAC__metadata_iterator_get_block()
1157  *  points directly into the chain.
1158  *
1159  * \warning
1160  * Do not call FLAC__metadata_object_delete() on the returned object;
1161  * to delete a block use FLAC__metadata_iterator_delete_block().
1162  *
1163  * \param iterator  A pointer to an existing initialized iterator.
1164  * \assert
1165  *    \code iterator != NULL \endcode
1166  *    \a iterator has been successfully initialized with
1167  *    FLAC__metadata_iterator_init()
1168  * \retval FLAC__StreamMetadata*
1169  *    The current metadata block.
1170  */
1171 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator);
1172 
1173 /** Set the metadata block at the current position, replacing the existing
1174  *  block.  The new block passed in becomes owned by the chain and it will be
1175  *  deleted when the chain is deleted.
1176  *
1177  * \param iterator  A pointer to an existing initialized iterator.
1178  * \param block     A pointer to a metadata block.
1179  * \assert
1180  *    \code iterator != NULL \endcode
1181  *    \a iterator has been successfully initialized with
1182  *    FLAC__metadata_iterator_init()
1183  *    \code block != NULL \endcode
1184  * \retval FLAC__bool
1185  *    \c false if the conditions in the above description are not met, or
1186  *    a memory allocation error occurs, otherwise \c true.
1187  */
1188 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1189 
1190 /** Removes the current block from the chain.  If \a replace_with_padding is
1191  *  \c true, the block will instead be replaced with a padding block of equal
1192  *  size.  You can not delete the STREAMINFO block.  The iterator will be
1193  *  left pointing to the block before the one just "deleted", even if
1194  *  \a replace_with_padding is \c true.
1195  *
1196  * \param iterator              A pointer to an existing initialized iterator.
1197  * \param replace_with_padding  See above.
1198  * \assert
1199  *    \code iterator != NULL \endcode
1200  *    \a iterator has been successfully initialized with
1201  *    FLAC__metadata_iterator_init()
1202  * \retval FLAC__bool
1203  *    \c false if the conditions in the above description are not met,
1204  *    otherwise \c true.
1205  */
1206 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding);
1207 
1208 /** Insert a new block before the current block.  You cannot insert a block
1209  *  before the first STREAMINFO block.  You cannot insert a STREAMINFO block
1210  *  as there can be only one, the one that already exists at the head when you
1211  *  read in a chain.  The chain takes ownership of the new block and it will be
1212  *  deleted when the chain is deleted.  The iterator will be left pointing to
1213  *  the new block.
1214  *
1215  * \param iterator  A pointer to an existing initialized iterator.
1216  * \param block     A pointer to a metadata block to insert.
1217  * \assert
1218  *    \code iterator != NULL \endcode
1219  *    \a iterator has been successfully initialized with
1220  *    FLAC__metadata_iterator_init()
1221  * \retval FLAC__bool
1222  *    \c false if the conditions in the above description are not met, or
1223  *    a memory allocation error occurs, otherwise \c true.
1224  */
1225 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1226 
1227 /** Insert a new block after the current block.  You cannot insert a STREAMINFO
1228  *  block as there can be only one, the one that already exists at the head when
1229  *  you read in a chain.  The chain takes ownership of the new block and it will
1230  *  be deleted when the chain is deleted.  The iterator will be left pointing to
1231  *  the new block.
1232  *
1233  * \param iterator  A pointer to an existing initialized iterator.
1234  * \param block     A pointer to a metadata block to insert.
1235  * \assert
1236  *    \code iterator != NULL \endcode
1237  *    \a iterator has been successfully initialized with
1238  *    FLAC__metadata_iterator_init()
1239  * \retval FLAC__bool
1240  *    \c false if the conditions in the above description are not met, or
1241  *    a memory allocation error occurs, otherwise \c true.
1242  */
1243 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
1244 
1245 /* \} */
1246 
1247 
1248 /** \defgroup flac_metadata_object FLAC/metadata.h: metadata object methods
1249  *  \ingroup flac_metadata
1250  *
1251  * \brief
1252  * This module contains methods for manipulating FLAC metadata objects.
1253  *
1254  * Since many are variable length we have to be careful about the memory
1255  * management.  We decree that all pointers to data in the object are
1256  * owned by the object and memory-managed by the object.
1257  *
1258  * Use the FLAC__metadata_object_new() and FLAC__metadata_object_delete()
1259  * functions to create all instances.  When using the
1260  * FLAC__metadata_object_set_*() functions to set pointers to data, set
1261  * \a copy to \c true to have the function make it's own copy of the data, or
1262  * to \c false to give the object ownership of your data.  In the latter case
1263  * your pointer must be freeable by free() and will be free()d when the object
1264  * is FLAC__metadata_object_delete()d.  It is legal to pass a null pointer as
1265  * the data pointer to a FLAC__metadata_object_set_*() function as long as
1266  * the length argument is 0 and the \a copy argument is \c false.
1267  *
1268  * The FLAC__metadata_object_new() and FLAC__metadata_object_clone() function
1269  * will return \c NULL in the case of a memory allocation error, otherwise a new
1270  * object.  The FLAC__metadata_object_set_*() functions return \c false in the
1271  * case of a memory allocation error.
1272  *
1273  * We don't have the convenience of C++ here, so note that the library relies
1274  * on you to keep the types straight.  In other words, if you pass, for
1275  * example, a FLAC__StreamMetadata* that represents a STREAMINFO block to
1276  * FLAC__metadata_object_application_set_data(), you will get an assertion
1277  * failure.
1278  *
1279  * For convenience the FLAC__metadata_object_vorbiscomment_*() functions
1280  * maintain a trailing NUL on each Vorbis comment entry.  This is not counted
1281  * toward the length or stored in the stream, but it can make working with plain
1282  * comments (those that don't contain embedded-NULs in the value) easier.
1283  * Entries passed into these functions have trailing NULs added if missing, and
1284  * returned entries are guaranteed to have a trailing NUL.
1285  *
1286  * The FLAC__metadata_object_vorbiscomment_*() functions that take a Vorbis
1287  * comment entry/name/value will first validate that it complies with the Vorbis
1288  * comment specification and return false if it does not.
1289  *
1290  * There is no need to recalculate the length field on metadata blocks you
1291  * have modified.  They will be calculated automatically before they  are
1292  * written back to a file.
1293  *
1294  * \{
1295  */
1296 
1297 
1298 /** Create a new metadata object instance of the given type.
1299  *
1300  *  The object will be "empty"; i.e. values and data pointers will be \c 0,
1301  *  with the exception of FLAC__METADATA_TYPE_VORBIS_COMMENT, which will have
1302  *  the vendor string set (but zero comments).
1303  *
1304  *  Do not pass in a value greater than or equal to
1305  *  \a FLAC__METADATA_TYPE_UNDEFINED unless you really know what you're
1306  *  doing.
1307  *
1308  * \param type  Type of object to create
1309  * \retval FLAC__StreamMetadata*
1310  *    \c NULL if there was an error allocating memory or the type code is
1311  *    greater than FLAC__MAX_METADATA_TYPE_CODE, else the new instance.
1312  */
1313 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_new(FLAC__MetadataType type);
1314 
1315 /** Create a copy of an existing metadata object.
1316  *
1317  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
1318  *  object is also copied.  The caller takes ownership of the new block and
1319  *  is responsible for freeing it with FLAC__metadata_object_delete().
1320  *
1321  * \param object  Pointer to object to copy.
1322  * \assert
1323  *    \code object != NULL \endcode
1324  * \retval FLAC__StreamMetadata*
1325  *    \c NULL if there was an error allocating memory, else the new instance.
1326  */
1327 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_clone(const FLAC__StreamMetadata *object);
1328 
1329 /** Free a metadata object.  Deletes the object pointed to by \a object.
1330  *
1331  *  The delete is a "deep" delete, i.e. dynamically allocated data within the
1332  *  object is also deleted.
1333  *
1334  * \param object  A pointer to an existing object.
1335  * \assert
1336  *    \code object != NULL \endcode
1337  */
1338 FLAC_API void FLAC__metadata_object_delete(FLAC__StreamMetadata *object);
1339 
1340 /** Compares two metadata objects.
1341  *
1342  *  The compare is "deep", i.e. dynamically allocated data within the
1343  *  object is also compared.
1344  *
1345  * \param block1  A pointer to an existing object.
1346  * \param block2  A pointer to an existing object.
1347  * \assert
1348  *    \code block1 != NULL \endcode
1349  *    \code block2 != NULL \endcode
1350  * \retval FLAC__bool
1351  *    \c true if objects are identical, else \c false.
1352  */
1353 FLAC_API FLAC__bool FLAC__metadata_object_is_equal(const FLAC__StreamMetadata *block1, const FLAC__StreamMetadata *block2);
1354 
1355 /** Sets the application data of an APPLICATION block.
1356  *
1357  *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
1358  *  takes ownership of the pointer.  The existing data will be freed if this
1359  *  function is successful, otherwise the original data will remain if \a copy
1360  *  is \c true and malloc() fails.
1361  *
1362  * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
1363  *
1364  * \param object  A pointer to an existing APPLICATION object.
1365  * \param data    A pointer to the data to set.
1366  * \param length  The length of \a data in bytes.
1367  * \param copy    See above.
1368  * \assert
1369  *    \code object != NULL \endcode
1370  *    \code object->type == FLAC__METADATA_TYPE_APPLICATION \endcode
1371  *    \code (data != NULL && length > 0) ||
1372  * (data == NULL && length == 0 && copy == false) \endcode
1373  * \retval FLAC__bool
1374  *    \c false if \a copy is \c true and malloc() fails, else \c true.
1375  */
1376 FLAC_API FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, unsigned length, FLAC__bool copy);
1377 
1378 /** Resize the seekpoint array.
1379  *
1380  *  If the size shrinks, elements will truncated; if it grows, new placeholder
1381  *  points will be added to the end.
1382  *
1383  * \param object          A pointer to an existing SEEKTABLE object.
1384  * \param new_num_points  The desired length of the array; may be \c 0.
1385  * \assert
1386  *    \code object != NULL \endcode
1387  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1388  *    \code (object->data.seek_table.points == NULL && object->data.seek_table.num_points == 0) ||
1389  * (object->data.seek_table.points != NULL && object->data.seek_table.num_points > 0) \endcode
1390  * \retval FLAC__bool
1391  *    \c false if memory allocation error, else \c true.
1392  */
1393 FLAC_API FLAC__bool FLAC__metadata_object_seektable_resize_points(FLAC__StreamMetadata *object, unsigned new_num_points);
1394 
1395 /** Set a seekpoint in a seektable.
1396  *
1397  * \param object     A pointer to an existing SEEKTABLE object.
1398  * \param point_num  Index into seekpoint array to set.
1399  * \param point      The point to set.
1400  * \assert
1401  *    \code object != NULL \endcode
1402  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1403  *    \code object->data.seek_table.num_points > point_num \endcode
1404  */
1405 FLAC_API void FLAC__metadata_object_seektable_set_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
1406 
1407 /** Insert a seekpoint into a seektable.
1408  *
1409  * \param object     A pointer to an existing SEEKTABLE object.
1410  * \param point_num  Index into seekpoint array to set.
1411  * \param point      The point to set.
1412  * \assert
1413  *    \code object != NULL \endcode
1414  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1415  *    \code object->data.seek_table.num_points >= point_num \endcode
1416  * \retval FLAC__bool
1417  *    \c false if memory allocation error, else \c true.
1418  */
1419 FLAC_API FLAC__bool FLAC__metadata_object_seektable_insert_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
1420 
1421 /** Delete a seekpoint from a seektable.
1422  *
1423  * \param object     A pointer to an existing SEEKTABLE object.
1424  * \param point_num  Index into seekpoint array to set.
1425  * \assert
1426  *    \code object != NULL \endcode
1427  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1428  *    \code object->data.seek_table.num_points > point_num \endcode
1429  * \retval FLAC__bool
1430  *    \c false if memory allocation error, else \c true.
1431  */
1432 FLAC_API FLAC__bool FLAC__metadata_object_seektable_delete_point(FLAC__StreamMetadata *object, unsigned point_num);
1433 
1434 /** Check a seektable to see if it conforms to the FLAC specification.
1435  *  See the format specification for limits on the contents of the
1436  *  seektable.
1437  *
1438  * \param object  A pointer to an existing SEEKTABLE object.
1439  * \assert
1440  *    \code object != NULL \endcode
1441  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1442  * \retval FLAC__bool
1443  *    \c false if seek table is illegal, else \c true.
1444  */
1445 FLAC_API FLAC__bool FLAC__metadata_object_seektable_is_legal(const FLAC__StreamMetadata *object);
1446 
1447 /** Append a number of placeholder points to the end of a seek table.
1448  *
1449  * \note
1450  * As with the other ..._seektable_template_... functions, you should
1451  * call FLAC__metadata_object_seektable_template_sort() when finished
1452  * to make the seek table legal.
1453  *
1454  * \param object  A pointer to an existing SEEKTABLE object.
1455  * \param num     The number of placeholder points to append.
1456  * \assert
1457  *    \code object != NULL \endcode
1458  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1459  * \retval FLAC__bool
1460  *    \c false if memory allocation fails, else \c true.
1461  */
1462 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_placeholders(FLAC__StreamMetadata *object, unsigned num);
1463 
1464 /** Append a specific seek point template to the end of a seek table.
1465  *
1466  * \note
1467  * As with the other ..._seektable_template_... functions, you should
1468  * call FLAC__metadata_object_seektable_template_sort() when finished
1469  * to make the seek table legal.
1470  *
1471  * \param object  A pointer to an existing SEEKTABLE object.
1472  * \param sample_number  The sample number of the seek point template.
1473  * \assert
1474  *    \code object != NULL \endcode
1475  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1476  * \retval FLAC__bool
1477  *    \c false if memory allocation fails, else \c true.
1478  */
1479 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_point(FLAC__StreamMetadata *object, FLAC__uint64 sample_number);
1480 
1481 /** Append specific seek point templates to the end of a seek table.
1482  *
1483  * \note
1484  * As with the other ..._seektable_template_... functions, you should
1485  * call FLAC__metadata_object_seektable_template_sort() when finished
1486  * to make the seek table legal.
1487  *
1488  * \param object  A pointer to an existing SEEKTABLE object.
1489  * \param sample_numbers  An array of sample numbers for the seek points.
1490  * \param num     The number of seek point templates to append.
1491  * \assert
1492  *    \code object != NULL \endcode
1493  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1494  * \retval FLAC__bool
1495  *    \c false if memory allocation fails, else \c true.
1496  */
1497 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_points(FLAC__StreamMetadata *object, FLAC__uint64 sample_numbers[], unsigned num);
1498 
1499 /** Append a set of evenly-spaced seek point templates to the end of a
1500  *  seek table.
1501  *
1502  * \note
1503  * As with the other ..._seektable_template_... functions, you should
1504  * call FLAC__metadata_object_seektable_template_sort() when finished
1505  * to make the seek table legal.
1506  *
1507  * \param object  A pointer to an existing SEEKTABLE object.
1508  * \param num     The number of placeholder points to append.
1509  * \param total_samples  The total number of samples to be encoded;
1510  *                       the seekpoints will be spaced approximately
1511  *                       \a total_samples / \a num samples apart.
1512  * \assert
1513  *    \code object != NULL \endcode
1514  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1515  *    \code total_samples > 0 \endcode
1516  * \retval FLAC__bool
1517  *    \c false if memory allocation fails, else \c true.
1518  */
1519 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points(FLAC__StreamMetadata *object, unsigned num, FLAC__uint64 total_samples);
1520 
1521 /** Append a set of evenly-spaced seek point templates to the end of a
1522  *  seek table.
1523  *
1524  * \note
1525  * As with the other ..._seektable_template_... functions, you should
1526  * call FLAC__metadata_object_seektable_template_sort() when finished
1527  * to make the seek table legal.
1528  *
1529  * \param object  A pointer to an existing SEEKTABLE object.
1530  * \param samples The number of samples apart to space the placeholder
1531  *                points.  The first point will be at sample \c 0, the
1532  *                second at sample \a samples, then 2*\a samples, and
1533  *                so on.  As long as \a samples and \a total_samples
1534  *                are greater than \c 0, there will always be at least
1535  *                one seekpoint at sample \c 0.
1536  * \param total_samples  The total number of samples to be encoded;
1537  *                       the seekpoints will be spaced
1538  *                       \a samples samples apart.
1539  * \assert
1540  *    \code object != NULL \endcode
1541  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1542  *    \code samples > 0 \endcode
1543  *    \code total_samples > 0 \endcode
1544  * \retval FLAC__bool
1545  *    \c false if memory allocation fails, else \c true.
1546  */
1547 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points_by_samples(FLAC__StreamMetadata *object, unsigned samples, FLAC__uint64 total_samples);
1548 
1549 /** Sort a seek table's seek points according to the format specification,
1550  *  removing duplicates.
1551  *
1552  * \param object   A pointer to a seek table to be sorted.
1553  * \param compact  If \c false, behaves like FLAC__format_seektable_sort().
1554  *                 If \c true, duplicates are deleted and the seek table is
1555  *                 shrunk appropriately; the number of placeholder points
1556  *                 present in the seek table will be the same after the call
1557  *                 as before.
1558  * \assert
1559  *    \code object != NULL \endcode
1560  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
1561  * \retval FLAC__bool
1562  *    \c false if realloc() fails, else \c true.
1563  */
1564 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_sort(FLAC__StreamMetadata *object, FLAC__bool compact);
1565 
1566 /** Sets the vendor string in a VORBIS_COMMENT block.
1567  *
1568  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1569  *  one already.
1570  *
1571  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1572  *  takes ownership of the \c entry.entry pointer.
1573  *
1574  *  \note If this function returns \c false, the caller still owns the
1575  *  pointer.
1576  *
1577  * \param object  A pointer to an existing VORBIS_COMMENT object.
1578  * \param entry   The entry to set the vendor string to.
1579  * \param copy    See above.
1580  * \assert
1581  *    \code object != NULL \endcode
1582  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1583  *    \code (entry.entry != NULL && entry.length > 0) ||
1584  * (entry.entry == NULL && entry.length == 0) \endcode
1585  * \retval FLAC__bool
1586  *    \c false if memory allocation fails or \a entry does not comply with the
1587  *    Vorbis comment specification, else \c true.
1588  */
1589 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1590 
1591 /** Resize the comment array.
1592  *
1593  *  If the size shrinks, elements will truncated; if it grows, new empty
1594  *  fields will be added to the end.
1595  *
1596  * \param object            A pointer to an existing VORBIS_COMMENT object.
1597  * \param new_num_comments  The desired length of the array; may be \c 0.
1598  * \assert
1599  *    \code object != NULL \endcode
1600  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1601  *    \code (object->data.vorbis_comment.comments == NULL && object->data.vorbis_comment.num_comments == 0) ||
1602  * (object->data.vorbis_comment.comments != NULL && object->data.vorbis_comment.num_comments > 0) \endcode
1603  * \retval FLAC__bool
1604  *    \c false if memory allocation fails, else \c true.
1605  */
1606 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_resize_comments(FLAC__StreamMetadata *object, unsigned new_num_comments);
1607 
1608 /** Sets a comment in a VORBIS_COMMENT block.
1609  *
1610  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1611  *  one already.
1612  *
1613  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1614  *  takes ownership of the \c entry.entry pointer.
1615  *
1616  *  \note If this function returns \c false, the caller still owns the
1617  *  pointer.
1618  *
1619  * \param object       A pointer to an existing VORBIS_COMMENT object.
1620  * \param comment_num  Index into comment array to set.
1621  * \param entry        The entry to set the comment to.
1622  * \param copy         See above.
1623  * \assert
1624  *    \code object != NULL \endcode
1625  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1626  *    \code comment_num < object->data.vorbis_comment.num_comments \endcode
1627  *    \code (entry.entry != NULL && entry.length > 0) ||
1628  * (entry.entry == NULL && entry.length == 0) \endcode
1629  * \retval FLAC__bool
1630  *    \c false if memory allocation fails or \a entry does not comply with the
1631  *    Vorbis comment specification, else \c true.
1632  */
1633 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1634 
1635 /** Insert a comment in a VORBIS_COMMENT block at the given index.
1636  *
1637  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1638  *  one already.
1639  *
1640  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1641  *  takes ownership of the \c entry.entry pointer.
1642  *
1643  *  \note If this function returns \c false, the caller still owns the
1644  *  pointer.
1645  *
1646  * \param object       A pointer to an existing VORBIS_COMMENT object.
1647  * \param comment_num  The index at which to insert the comment.  The comments
1648  *                     at and after \a comment_num move right one position.
1649  *                     To append a comment to the end, set \a comment_num to
1650  *                     \c object->data.vorbis_comment.num_comments .
1651  * \param entry        The comment to insert.
1652  * \param copy         See above.
1653  * \assert
1654  *    \code object != NULL \endcode
1655  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1656  *    \code object->data.vorbis_comment.num_comments >= comment_num \endcode
1657  *    \code (entry.entry != NULL && entry.length > 0) ||
1658  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1659  * \retval FLAC__bool
1660  *    \c false if memory allocation fails or \a entry does not comply with the
1661  *    Vorbis comment specification, else \c true.
1662  */
1663 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_insert_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1664 
1665 /** Appends a comment to a VORBIS_COMMENT block.
1666  *
1667  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1668  *  one already.
1669  *
1670  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1671  *  takes ownership of the \c entry.entry pointer.
1672  *
1673  *  \note If this function returns \c false, the caller still owns the
1674  *  pointer.
1675  *
1676  * \param object       A pointer to an existing VORBIS_COMMENT object.
1677  * \param entry        The comment to insert.
1678  * \param copy         See above.
1679  * \assert
1680  *    \code object != NULL \endcode
1681  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1682  *    \code (entry.entry != NULL && entry.length > 0) ||
1683  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1684  * \retval FLAC__bool
1685  *    \c false if memory allocation fails or \a entry does not comply with the
1686  *    Vorbis comment specification, else \c true.
1687  */
1688 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_append_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
1689 
1690 /** Replaces comments in a VORBIS_COMMENT block with a new one.
1691  *
1692  *  For convenience, a trailing NUL is added to the entry if it doesn't have
1693  *  one already.
1694  *
1695  *  Depending on the value of \a all, either all or just the first comment
1696  *  whose field name(s) match the given entry's name will be replaced by the
1697  *  given entry.  If no comments match, \a entry will simply be appended.
1698  *
1699  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
1700  *  takes ownership of the \c entry.entry pointer.
1701  *
1702  *  \note If this function returns \c false, the caller still owns the
1703  *  pointer.
1704  *
1705  * \param object       A pointer to an existing VORBIS_COMMENT object.
1706  * \param entry        The comment to insert.
1707  * \param all          If \c true, all comments whose field name matches
1708  *                     \a entry's field name will be removed, and \a entry will
1709  *                     be inserted at the position of the first matching
1710  *                     comment.  If \c false, only the first comment whose
1711  *                     field name matches \a entry's field name will be
1712  *                     replaced with \a entry.
1713  * \param copy         See above.
1714  * \assert
1715  *    \code object != NULL \endcode
1716  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1717  *    \code (entry.entry != NULL && entry.length > 0) ||
1718  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
1719  * \retval FLAC__bool
1720  *    \c false if memory allocation fails or \a entry does not comply with the
1721  *    Vorbis comment specification, else \c true.
1722  */
1723 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_replace_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool all, FLAC__bool copy);
1724 
1725 /** Delete a comment in a VORBIS_COMMENT block at the given index.
1726  *
1727  * \param object       A pointer to an existing VORBIS_COMMENT object.
1728  * \param comment_num  The index of the comment to delete.
1729  * \assert
1730  *    \code object != NULL \endcode
1731  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1732  *    \code object->data.vorbis_comment.num_comments > comment_num \endcode
1733  * \retval FLAC__bool
1734  *    \c false if realloc() fails, else \c true.
1735  */
1736 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_delete_comment(FLAC__StreamMetadata *object, unsigned comment_num);
1737 
1738 /** Creates a Vorbis comment entry from NUL-terminated name and value strings.
1739  *
1740  *  On return, the filled-in \a entry->entry pointer will point to malloc()ed
1741  *  memory and shall be owned by the caller.  For convenience the entry will
1742  *  have a terminating NUL.
1743  *
1744  * \param entry              A pointer to a Vorbis comment entry.  The entry's
1745  *                           \c entry pointer should not point to allocated
1746  *                           memory as it will be overwritten.
1747  * \param field_name         The field name in ASCII, \c NUL terminated.
1748  * \param field_value        The field value in UTF-8, \c NUL terminated.
1749  * \assert
1750  *    \code entry != NULL \endcode
1751  *    \code field_name != NULL \endcode
1752  *    \code field_value != NULL \endcode
1753  * \retval FLAC__bool
1754  *    \c false if malloc() fails, or if \a field_name or \a field_value does
1755  *    not comply with the Vorbis comment specification, else \c true.
1756  */
1757 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);
1758 
1759 /** Splits a Vorbis comment entry into NUL-terminated name and value strings.
1760  *
1761  *  The returned pointers to name and value will be allocated by malloc()
1762  *  and shall be owned by the caller.
1763  *
1764  * \param entry              An existing Vorbis comment entry.
1765  * \param field_name         The address of where the returned pointer to the
1766  *                           field name will be stored.
1767  * \param field_value        The address of where the returned pointer to the
1768  *                           field value will be stored.
1769  * \assert
1770  *    \code (entry.entry != NULL && entry.length > 0) \endcode
1771  *    \code memchr(entry.entry, '=', entry.length) != NULL \endcode
1772  *    \code field_name != NULL \endcode
1773  *    \code field_value != NULL \endcode
1774  * \retval FLAC__bool
1775  *    \c false if memory allocation fails or \a entry does not comply with the
1776  *    Vorbis comment specification, else \c true.
1777  */
1778 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);
1779 
1780 /** Check if the given Vorbis comment entry's field name matches the given
1781  *  field name.
1782  *
1783  * \param entry              An existing Vorbis comment entry.
1784  * \param field_name         The field name to check.
1785  * \param field_name_length  The length of \a field_name, not including the
1786  *                           terminating \c NUL.
1787  * \assert
1788  *    \code (entry.entry != NULL && entry.length > 0) \endcode
1789  * \retval FLAC__bool
1790  *    \c true if the field names match, else \c false
1791  */
1792 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_matches(const FLAC__StreamMetadata_VorbisComment_Entry entry, const char *field_name, unsigned field_name_length);
1793 
1794 /** Find a Vorbis comment with the given field name.
1795  *
1796  *  The search begins at entry number \a offset; use an offset of 0 to
1797  *  search from the beginning of the comment array.
1798  *
1799  * \param object      A pointer to an existing VORBIS_COMMENT object.
1800  * \param offset      The offset into the comment array from where to start
1801  *                    the search.
1802  * \param field_name  The field name of the comment to find.
1803  * \assert
1804  *    \code object != NULL \endcode
1805  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1806  *    \code field_name != NULL \endcode
1807  * \retval int
1808  *    The offset in the comment array of the first comment whose field
1809  *    name matches \a field_name, or \c -1 if no match was found.
1810  */
1811 FLAC_API int FLAC__metadata_object_vorbiscomment_find_entry_from(const FLAC__StreamMetadata *object, unsigned offset, const char *field_name);
1812 
1813 /** Remove first Vorbis comment matching the given field name.
1814  *
1815  * \param object      A pointer to an existing VORBIS_COMMENT object.
1816  * \param field_name  The field name of comment to delete.
1817  * \assert
1818  *    \code object != NULL \endcode
1819  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1820  * \retval int
1821  *    \c -1 for memory allocation error, \c 0 for no matching entries,
1822  *    \c 1 for one matching entry deleted.
1823  */
1824 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entry_matching(FLAC__StreamMetadata *object, const char *field_name);
1825 
1826 /** Remove all Vorbis comments matching the given field name.
1827  *
1828  * \param object      A pointer to an existing VORBIS_COMMENT object.
1829  * \param field_name  The field name of comments to delete.
1830  * \assert
1831  *    \code object != NULL \endcode
1832  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
1833  * \retval int
1834  *    \c -1 for memory allocation error, \c 0 for no matching entries,
1835  *    else the number of matching entries deleted.
1836  */
1837 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entries_matching(FLAC__StreamMetadata *object, const char *field_name);
1838 
1839 /** Create a new CUESHEET track instance.
1840  *
1841  *  The object will be "empty"; i.e. values and data pointers will be \c 0.
1842  *
1843  * \retval FLAC__StreamMetadata_CueSheet_Track*
1844  *    \c NULL if there was an error allocating memory, else the new instance.
1845  */
1846 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_new(void);
1847 
1848 /** Create a copy of an existing CUESHEET track object.
1849  *
1850  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
1851  *  object is also copied.  The caller takes ownership of the new object and
1852  *  is responsible for freeing it with
1853  *  FLAC__metadata_object_cuesheet_track_delete().
1854  *
1855  * \param object  Pointer to object to copy.
1856  * \assert
1857  *    \code object != NULL \endcode
1858  * \retval FLAC__StreamMetadata_CueSheet_Track*
1859  *    \c NULL if there was an error allocating memory, else the new instance.
1860  */
1861 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_clone(const FLAC__StreamMetadata_CueSheet_Track *object);
1862 
1863 /** Delete a CUESHEET track object
1864  *
1865  * \param object       A pointer to an existing CUESHEET track object.
1866  * \assert
1867  *    \code object != NULL \endcode
1868  */
1869 FLAC_API void FLAC__metadata_object_cuesheet_track_delete(FLAC__StreamMetadata_CueSheet_Track *object);
1870 
1871 /** Resize a track's index point array.
1872  *
1873  *  If the size shrinks, elements will truncated; if it grows, new blank
1874  *  indices will be added to the end.
1875  *
1876  * \param object           A pointer to an existing CUESHEET object.
1877  * \param track_num        The index of the track to modify.  NOTE: this is not
1878  *                         necessarily the same as the track's \a number field.
1879  * \param new_num_indices  The desired length of the array; may be \c 0.
1880  * \assert
1881  *    \code object != NULL \endcode
1882  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1883  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1884  *    \code (object->data.cue_sheet.tracks[track_num].indices == NULL && object->data.cue_sheet.tracks[track_num].num_indices == 0) ||
1885  * (object->data.cue_sheet.tracks[track_num].indices != NULL && object->data.cue_sheet.tracks[track_num].num_indices > 0) \endcode
1886  * \retval FLAC__bool
1887  *    \c false if memory allocation error, else \c true.
1888  */
1889 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_resize_indices(FLAC__StreamMetadata *object, unsigned track_num, unsigned new_num_indices);
1890 
1891 /** Insert an index point in a CUESHEET track at the given index.
1892  *
1893  * \param object       A pointer to an existing CUESHEET object.
1894  * \param track_num    The index of the track to modify.  NOTE: this is not
1895  *                     necessarily the same as the track's \a number field.
1896  * \param index_num    The index into the track's index array at which to
1897  *                     insert the index point.  NOTE: this is not necessarily
1898  *                     the same as the index point's \a number field.  The
1899  *                     indices at and after \a index_num move right one
1900  *                     position.  To append an index point to the end, set
1901  *                     \a index_num to
1902  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
1903  * \param index        The index point to insert.
1904  * \assert
1905  *    \code object != NULL \endcode
1906  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1907  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1908  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
1909  * \retval FLAC__bool
1910  *    \c false if realloc() fails, else \c true.
1911  */
1912 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);
1913 
1914 /** Insert a blank index point in a CUESHEET track at the given index.
1915  *
1916  *  A blank index point is one in which all field values are zero.
1917  *
1918  * \param object       A pointer to an existing CUESHEET object.
1919  * \param track_num    The index of the track to modify.  NOTE: this is not
1920  *                     necessarily the same as the track's \a number field.
1921  * \param index_num    The index into the track's index array at which to
1922  *                     insert the index point.  NOTE: this is not necessarily
1923  *                     the same as the index point's \a number field.  The
1924  *                     indices at and after \a index_num move right one
1925  *                     position.  To append an index point to the end, set
1926  *                     \a index_num to
1927  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
1928  * \assert
1929  *    \code object != NULL \endcode
1930  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1931  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1932  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
1933  * \retval FLAC__bool
1934  *    \c false if realloc() fails, else \c true.
1935  */
1936 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_blank_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
1937 
1938 /** Delete an index point in a CUESHEET track at the given index.
1939  *
1940  * \param object       A pointer to an existing CUESHEET object.
1941  * \param track_num    The index into the track array of the track to
1942  *                     modify.  NOTE: this is not necessarily the same
1943  *                     as the track's \a number field.
1944  * \param index_num    The index into the track's index array of the index
1945  *                     to delete.  NOTE: this is not necessarily the same
1946  *                     as the index's \a number field.
1947  * \assert
1948  *    \code object != NULL \endcode
1949  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1950  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
1951  *    \code object->data.cue_sheet.tracks[track_num].num_indices > index_num \endcode
1952  * \retval FLAC__bool
1953  *    \c false if realloc() fails, else \c true.
1954  */
1955 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_delete_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
1956 
1957 /** Resize the track array.
1958  *
1959  *  If the size shrinks, elements will truncated; if it grows, new blank
1960  *  tracks will be added to the end.
1961  *
1962  * \param object            A pointer to an existing CUESHEET object.
1963  * \param new_num_tracks    The desired length of the array; may be \c 0.
1964  * \assert
1965  *    \code object != NULL \endcode
1966  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1967  *    \code (object->data.cue_sheet.tracks == NULL && object->data.cue_sheet.num_tracks == 0) ||
1968  * (object->data.cue_sheet.tracks != NULL && object->data.cue_sheet.num_tracks > 0) \endcode
1969  * \retval FLAC__bool
1970  *    \c false if memory allocation error, else \c true.
1971  */
1972 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_resize_tracks(FLAC__StreamMetadata *object, unsigned new_num_tracks);
1973 
1974 /** Sets a track in a CUESHEET block.
1975  *
1976  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
1977  *  takes ownership of the \a track pointer.
1978  *
1979  * \param object       A pointer to an existing CUESHEET object.
1980  * \param track_num    Index into track array to set.  NOTE: this is not
1981  *                     necessarily the same as the track's \a number field.
1982  * \param track        The track to set the track to.  You may safely pass in
1983  *                     a const pointer if \a copy is \c true.
1984  * \param copy         See above.
1985  * \assert
1986  *    \code object != NULL \endcode
1987  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
1988  *    \code track_num < object->data.cue_sheet.num_tracks \endcode
1989  *    \code (track->indices != NULL && track->num_indices > 0) ||
1990  * (track->indices == NULL && track->num_indices == 0) \endcode
1991  * \retval FLAC__bool
1992  *    \c false if \a copy is \c true and malloc() fails, else \c true.
1993  */
1994 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_set_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
1995 
1996 /** Insert a track in a CUESHEET block at the given index.
1997  *
1998  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
1999  *  takes ownership of the \a track pointer.
2000  *
2001  * \param object       A pointer to an existing CUESHEET object.
2002  * \param track_num    The index at which to insert the track.  NOTE: this
2003  *                     is not necessarily the same as the track's \a number
2004  *                     field.  The tracks at and after \a track_num move right
2005  *                     one position.  To append a track to the end, set
2006  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
2007  * \param track        The track to insert.  You may safely pass in a const
2008  *                     pointer if \a copy is \c true.
2009  * \param copy         See above.
2010  * \assert
2011  *    \code object != NULL \endcode
2012  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2013  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
2014  * \retval FLAC__bool
2015  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2016  */
2017 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
2018 
2019 /** Insert a blank track in a CUESHEET block at the given index.
2020  *
2021  *  A blank track is one in which all field values are zero.
2022  *
2023  * \param object       A pointer to an existing CUESHEET object.
2024  * \param track_num    The index at which to insert the track.  NOTE: this
2025  *                     is not necessarily the same as the track's \a number
2026  *                     field.  The tracks at and after \a track_num move right
2027  *                     one position.  To append a track to the end, set
2028  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
2029  * \assert
2030  *    \code object != NULL \endcode
2031  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2032  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
2033  * \retval FLAC__bool
2034  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2035  */
2036 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_blank_track(FLAC__StreamMetadata *object, unsigned track_num);
2037 
2038 /** Delete a track in a CUESHEET block at the given index.
2039  *
2040  * \param object       A pointer to an existing CUESHEET object.
2041  * \param track_num    The index into the track array of the track to
2042  *                     delete.  NOTE: this is not necessarily the same
2043  *                     as the track's \a number field.
2044  * \assert
2045  *    \code object != NULL \endcode
2046  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2047  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
2048  * \retval FLAC__bool
2049  *    \c false if realloc() fails, else \c true.
2050  */
2051 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_delete_track(FLAC__StreamMetadata *object, unsigned track_num);
2052 
2053 /** Check a cue sheet to see if it conforms to the FLAC specification.
2054  *  See the format specification for limits on the contents of the
2055  *  cue sheet.
2056  *
2057  * \param object     A pointer to an existing CUESHEET object.
2058  * \param check_cd_da_subset  If \c true, check CUESHEET against more
2059  *                   stringent requirements for a CD-DA (audio) disc.
2060  * \param violation  Address of a pointer to a string.  If there is a
2061  *                   violation, a pointer to a string explanation of the
2062  *                   violation will be returned here. \a violation may be
2063  *                   \c NULL if you don't need the returned string.  Do not
2064  *                   free the returned string; it will always point to static
2065  *                   data.
2066  * \assert
2067  *    \code object != NULL \endcode
2068  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2069  * \retval FLAC__bool
2070  *    \c false if cue sheet is illegal, else \c true.
2071  */
2072 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_is_legal(const FLAC__StreamMetadata *object, FLAC__bool check_cd_da_subset, const char **violation);
2073 
2074 /** Calculate and return the CDDB/freedb ID for a cue sheet.  The function
2075  *  assumes the cue sheet corresponds to a CD; the result is undefined
2076  *  if the cuesheet's is_cd bit is not set.
2077  *
2078  * \param object     A pointer to an existing CUESHEET object.
2079  * \assert
2080  *    \code object != NULL \endcode
2081  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
2082  * \retval FLAC__uint32
2083  *    The unsigned integer representation of the CDDB/freedb ID
2084  */
2085 FLAC_API FLAC__uint32 FLAC__metadata_object_cuesheet_calculate_cddb_id(const FLAC__StreamMetadata *object);
2086 
2087 /** Sets the MIME type of a PICTURE block.
2088  *
2089  *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
2090  *  takes ownership of the pointer.  The existing string will be freed if this
2091  *  function is successful, otherwise the original string will remain if \a copy
2092  *  is \c true and malloc() fails.
2093  *
2094  * \note It is safe to pass a const pointer to \a mime_type if \a copy is \c true.
2095  *
2096  * \param object      A pointer to an existing PICTURE object.
2097  * \param mime_type   A pointer to the MIME type string.  The string must be
2098  *                    ASCII characters 0x20-0x7e, NUL-terminated.  No validation
2099  *                    is done.
2100  * \param copy        See above.
2101  * \assert
2102  *    \code object != NULL \endcode
2103  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2104  *    \code (mime_type != NULL) \endcode
2105  * \retval FLAC__bool
2106  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2107  */
2108 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_mime_type(FLAC__StreamMetadata *object, char *mime_type, FLAC__bool copy);
2109 
2110 /** Sets the description of a PICTURE block.
2111  *
2112  *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
2113  *  takes ownership of the pointer.  The existing string will be freed if this
2114  *  function is successful, otherwise the original string will remain if \a copy
2115  *  is \c true and malloc() fails.
2116  *
2117  * \note It is safe to pass a const pointer to \a description if \a copy is \c true.
2118  *
2119  * \param object      A pointer to an existing PICTURE object.
2120  * \param description A pointer to the description string.  The string must be
2121  *                    valid UTF-8, NUL-terminated.  No validation is done.
2122  * \param copy        See above.
2123  * \assert
2124  *    \code object != NULL \endcode
2125  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2126  *    \code (description != NULL) \endcode
2127  * \retval FLAC__bool
2128  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2129  */
2130 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_description(FLAC__StreamMetadata *object, FLAC__byte *description, FLAC__bool copy);
2131 
2132 /** Sets the picture data of a PICTURE block.
2133  *
2134  *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
2135  *  takes ownership of the pointer.  Also sets the \a data_length field of the
2136  *  metadata object to what is passed in as the \a length parameter.  The
2137  *  existing data will be freed if this function is successful, otherwise the
2138  *  original data and data_length will remain if \a copy is \c true and
2139  *  malloc() fails.
2140  *
2141  * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
2142  *
2143  * \param object  A pointer to an existing PICTURE object.
2144  * \param data    A pointer to the data to set.
2145  * \param length  The length of \a data in bytes.
2146  * \param copy    See above.
2147  * \assert
2148  *    \code object != NULL \endcode
2149  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2150  *    \code (data != NULL && length > 0) ||
2151  * (data == NULL && length == 0 && copy == false) \endcode
2152  * \retval FLAC__bool
2153  *    \c false if \a copy is \c true and malloc() fails, else \c true.
2154  */
2155 FLAC_API FLAC__bool FLAC__metadata_object_picture_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, FLAC__uint32 length, FLAC__bool copy);
2156 
2157 /** Check a PICTURE block to see if it conforms to the FLAC specification.
2158  *  See the format specification for limits on the contents of the
2159  *  PICTURE block.
2160  *
2161  * \param object     A pointer to existing PICTURE block to be checked.
2162  * \param violation  Address of a pointer to a string.  If there is a
2163  *                   violation, a pointer to a string explanation of the
2164  *                   violation will be returned here. \a violation may be
2165  *                   \c NULL if you don't need the returned string.  Do not
2166  *                   free the returned string; it will always point to static
2167  *                   data.
2168  * \assert
2169  *    \code object != NULL \endcode
2170  *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
2171  * \retval FLAC__bool
2172  *    \c false if PICTURE block is illegal, else \c true.
2173  */
2174 FLAC_API FLAC__bool FLAC__metadata_object_picture_is_legal(const FLAC__StreamMetadata *object, const char **violation);
2175 
2176 /* \} */
2177 
2178 #ifdef __cplusplus
2179 }
2180 #endif
2181 
2182 #endif
2183