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