vx32

metadata.h (83577B)

---

 /* libFLAC - Free Lossless Audio Codec library
  * Copyright (C) 2001,2002,2003,2004,2005  Josh Coalson
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * - Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
  * - Redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution.
  *
  * - Neither the name of the Xiph.org Foundation nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef FLAC__METADATA_H
 #define FLAC__METADATA_H
 
 #include "export.h"
 #include "callback.h"
 #include "format.h"
 
 /******************************************************************************
 	(For an example of how all these routines are used, see the source
 	code for the unit tests in src/test_libFLAC/metadata_*.c, or metaflac
 	in src/metaflac/)
 ******************************************************************************/
 
 /** \file include/FLAC/metadata.h
  *
  *  \brief
  *  This module provides functions for creating and manipulating FLAC
  *  metadata blocks in memory, and three progressively more powerful
  *  interfaces for traversing and editing metadata in FLAC files.
  *
  *  See the detailed documentation for each interface in the
  *  \link flac_metadata metadata \endlink module.
  */
 
 /** \defgroup flac_metadata FLAC/metadata.h: metadata interfaces
  *  \ingroup flac
  *
  *  \brief
  *  This module provides functions for creating and manipulating FLAC
  *  metadata blocks in memory, and three progressively more powerful
  *  interfaces for traversing and editing metadata in FLAC files.
  *
  *  There are three metadata interfaces of increasing complexity:
  *
  *  Level 0:
  *  Read-only access to the STREAMINFO and VORBIS_COMMENT blocks.
  *
  *  Level 1:
  *  Read-write access to all metadata blocks.  This level is write-
  *  efficient in most cases (more on this below), and uses less memory
  *  than level 2.
  *
  *  Level 2:
  *  Read-write access to all metadata blocks.  This level is write-
  *  efficient in all cases, but uses more memory since all metadata for
  *  the whole file is read into memory and manipulated before writing
  *  out again.
  *
  *  What do we mean by efficient?  Since FLAC metadata appears at the
  *  beginning of the file, when writing metadata back to a FLAC file
  *  it is possible to grow or shrink the metadata such that the entire
  *  file must be rewritten.  However, if the size remains the same during
  *  changes or PADDING blocks are utilized, only the metadata needs to be
  *  overwritten, which is much faster.
  *
  *  Efficient means the whole file is rewritten at most one time, and only
  *  when necessary.  Level 1 is not efficient only in the case that you
  *  cause more than one metadata block to grow or shrink beyond what can
  *  be accomodated by padding.  In this case you should probably use level
  *  2, which allows you to edit all the metadata for a file in memory and
  *  write it out all at once.
  *
  *  All levels know how to skip over and not disturb an ID3v2 tag at the
  *  front of the file.
  *
  *  All levels access files via their filenames.  In addition, level 2
  *  has additional alternative read and write functions that take an I/O
  *  handle and callbacks, for times when access by filename is not possible.
  *
  *  In addition to the three interfaces, this module defines functions for
  *  creating and manipulating various metadata objects in memory.  As we see
  *  from the Format module, FLAC metadata blocks in memory are very primitive
  *  structures for storing information in an efficient way.  Reading
  *  information from the structures is easy but creating or modifying them
  *  directly is more complex.  The metadata object routines here facilitate
  *  this by taking care of the consistency and memory management drudgery.
  *
  *  Unless you will be using the level 1 or 2 interfaces to modify existing
  *  metadata however, you will not probably not need these.
  *
  *  From a dependency standpoint, none of the encoders or decoders require
  *  the metadata module.  This is so that embedded users can strip out the
  *  metadata module from libFLAC to reduce the size and complexity.
  */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 
 /** \defgroup flac_metadata_level0 FLAC/metadata.h: metadata level 0 interface
  *  \ingroup flac_metadata
  *
  *  \brief
  *  The level 0 interface consists of individual routines to read the
  *  STREAMINFO and VORBIS_COMMENT blocks, requiring only a filename.
  *
  *  It skips any ID3v2 tag at the head of the file.
  *
  * \{
  */
 
 /** Read the STREAMINFO metadata block of the given FLAC file.  This function
  *  will skip any ID3v2 tag at the head of the file.
  *
  * \param filename    The path to the FLAC file to read.
  * \param streaminfo  A pointer to space for the STREAMINFO block.  Since
  *                    FLAC__StreamMetadata is a simple structure with no
  *                    memory allocation involved, you pass the address of
  *                    an existing structure.  It need not be initialized.
  * \assert
  *    \code filename != NULL \endcode
  *    \code streaminfo != NULL \endcode
  * \retval FLAC__bool
  *    \c true if a valid STREAMINFO block was read from \a filename.  Returns
  *    \c false if there was a memory allocation error, a file decoder error,
  *    or the file contained no STREAMINFO block.  (A memory allocation error
  *    is possible because this function must set up a file decoder.)
  */
 FLAC_API FLAC__bool FLAC__metadata_get_streaminfo(const char *filename, FLAC__StreamMetadata *streaminfo);
 
 /** Read the VORBIS_COMMENT metadata block of the given FLAC file.  This
  *  function will skip any ID3v2 tag at the head of the file.
  *
  * \param filename    The path to the FLAC file to read.
  * \param tags        The address where the returned pointer will be
  *                    stored.  The \a tags object must be deleted by
  *                    the caller using FLAC__metadata_object_delete().
  * \assert
  *    \code filename != NULL \endcode
  *    \code streaminfo != NULL \endcode
  * \retval FLAC__bool
  *    \c true if a valid VORBIS_COMMENT block was read from \a filename,
  *    and \a *tags will be set to the address of the tag structure.
  *    Returns \c false if there was a memory allocation error, a file
  *    decoder error, or the file contained no VORBIS_COMMENT block, and
  *    \a *tags will be set to \c NULL.
  */
 FLAC_API FLAC__bool FLAC__metadata_get_tags(const char *filename, FLAC__StreamMetadata **tags);
 
 /* \} */
 
 
 /** \defgroup flac_metadata_level1 FLAC/metadata.h: metadata level 1 interface
  *  \ingroup flac_metadata
  *
  * \brief
  * The level 1 interface provides read-write access to FLAC file metadata and
  * operates directly on the FLAC file.
  *
  * The general usage of this interface is:
  *
  * - Create an iterator using FLAC__metadata_simple_iterator_new()
  * - Attach it to a file using FLAC__metadata_simple_iterator_init() and check
  *   the exit code.  Call FLAC__metadata_simple_iterator_is_writable() to
  *   see if the file is writable, or read-only access is allowed.
  * - Use FLAC__metadata_simple_iterator_next() and
  *   FLAC__metadata_simple_iterator_prev() to move around the blocks.
  *   This is does not read the actual blocks themselves.
  *   FLAC__metadata_simple_iterator_next() is relatively fast.
  *   FLAC__metadata_simple_iterator_prev() is slower since it needs to search
  *   forward from the front of the file.
  * - Use FLAC__metadata_simple_iterator_get_block_type() or
  *   FLAC__metadata_simple_iterator_get_block() to access the actual data at
  *   the current iterator position.  The returned object is yours to modify
  *   and free.
  * - Use FLAC__metadata_simple_iterator_set_block() to write a modified block
  *   back.  You must have write permission to the original file.  Make sure to
  *   read the whole comment to FLAC__metadata_simple_iterator_set_block()
  *   below.
  * - Use FLAC__metadata_simple_iterator_insert_block_after() to add new blocks.
  *   Use the object creation functions from
  *   \link flac_metadata_object here \endlink to generate new objects.
  * - Use FLAC__metadata_simple_iterator_delete_block() to remove the block
  *   currently referred to by the iterator, or replace it with padding.
  * - Destroy the iterator with FLAC__metadata_simple_iterator_delete() when
  *   finished.
  *
  * \note
  * The FLAC file remains open the whole time between
  * FLAC__metadata_simple_iterator_init() and
  * FLAC__metadata_simple_iterator_delete(), so make sure you are not altering
  * the file during this time.
  *
  * \note
  * Do not modify the \a is_last, \a length, or \a type fields of returned
  * FLAC__StreamMetadata objects.  These are managed automatically.
  *
  * \note
  * If any of the modification functions
  * (FLAC__metadata_simple_iterator_set_block(),
  * FLAC__metadata_simple_iterator_delete_block(),
  * FLAC__metadata_simple_iterator_insert_block_after(), etc.) return \c false,
  * you should delete the iterator as it may no longer be valid.
  *
  * \{
  */
 
 struct FLAC__Metadata_SimpleIterator;
 /** The opaque structure definition for the level 1 iterator type.
  *  See the
  *  \link flac_metadata_level1 metadata level 1 module \endlink
  *  for a detailed description.
  */
 typedef struct FLAC__Metadata_SimpleIterator FLAC__Metadata_SimpleIterator;
 
 /** Status type for FLAC__Metadata_SimpleIterator.
  *
  *  The iterator's current status can be obtained by calling FLAC__metadata_simple_iterator_status().
  */
 typedef enum {
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK = 0,
 	/**< The iterator is in the normal OK state */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT,
 	/**< The data passed into a function violated the function's usage criteria */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE,
 	/**< The iterator could not open the target file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE,
 	/**< The iterator could not find the FLAC signature at the start of the file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_WRITABLE,
 	/**< The iterator tried to write to a file that was not writable */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_BAD_METADATA,
 	/**< The iterator encountered input that does not conform to the FLAC metadata specification */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR,
 	/**< The iterator encountered an error while reading the FLAC file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR,
 	/**< The iterator encountered an error while seeking in the FLAC file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_WRITE_ERROR,
 	/**< The iterator encountered an error while writing the FLAC file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_RENAME_ERROR,
 	/**< The iterator encountered an error renaming the FLAC file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_UNLINK_ERROR,
 	/**< The iterator encountered an error removing the temporary file */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_MEMORY_ALLOCATION_ERROR,
 	/**< Memory allocation failed */
 
 	FLAC__METADATA_SIMPLE_ITERATOR_STATUS_INTERNAL_ERROR
 	/**< The caller violated an assertion or an unexpected error occurred */
 
 } FLAC__Metadata_SimpleIteratorStatus;
 
 /** Maps a FLAC__Metadata_SimpleIteratorStatus to a C string.
  *
  *  Using a FLAC__Metadata_SimpleIteratorStatus as the index to this array
  *  will give the string equivalent.  The contents should not be modified.
  */
 extern FLAC_API const char * const FLAC__Metadata_SimpleIteratorStatusString[];
 
 
 /** Create a new iterator instance.
  *
  * \retval FLAC__Metadata_SimpleIterator*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__Metadata_SimpleIterator *FLAC__metadata_simple_iterator_new();
 
 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
  *
  * \param iterator  A pointer to an existing iterator.
  * \assert
  *    \code iterator != NULL \endcode
  */
 FLAC_API void FLAC__metadata_simple_iterator_delete(FLAC__Metadata_SimpleIterator *iterator);
 
 /** Get the current status of the iterator.  Call this after a function
  *  returns \c false to get the reason for the error.  Also resets the status
  *  to FLAC__METADATA_SIMPLE_ITERATOR_STATUS_OK.
  *
  * \param iterator  A pointer to an existing iterator.
  * \assert
  *    \code iterator != NULL \endcode
  * \retval FLAC__Metadata_SimpleIteratorStatus
  *    The current status of the iterator.
  */
 FLAC_API FLAC__Metadata_SimpleIteratorStatus FLAC__metadata_simple_iterator_status(FLAC__Metadata_SimpleIterator *iterator);
 
 /** Initialize the iterator to point to the first metadata block in the
  *  given FLAC file.
  *
  * \param iterator             A pointer to an existing iterator.
  * \param filename             The path to the FLAC file.
  * \param read_only            If \c true, the FLAC file will be opened
  *                             in read-only mode; if \c false, the FLAC
  *                             file will be opened for edit even if no
  *                             edits are performed.
  * \param preserve_file_stats  If \c true, the owner and modification
  *                             time will be preserved even if the FLAC
  *                             file is written to.
  * \assert
  *    \code iterator != NULL \endcode
  *    \code filename != NULL \endcode
  * \retval FLAC__bool
  *    \c false if a memory allocation error occurs, the file can't be
  *    opened, or another error occurs, else \c true.
  */
 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);
 
 /** Returns \c true if the FLAC file is writable.  If \c false, calls to
  *  FLAC__metadata_simple_iterator_set_block() and
  *  FLAC__metadata_simple_iterator_insert_block_after() will fail.
  *
  * \param iterator             A pointer to an existing iterator.
  * \assert
  *    \code iterator != NULL \endcode
  * \retval FLAC__bool
  *    See above.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_writable(const FLAC__Metadata_SimpleIterator *iterator);
 
 /** Moves the iterator forward one metadata block, returning \c false if
  *  already at the end.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  * \retval FLAC__bool
  *    \c false if already at the last metadata block of the chain, else
  *    \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_next(FLAC__Metadata_SimpleIterator *iterator);
 
 /** Moves the iterator backward one metadata block, returning \c false if
  *  already at the beginning.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  * \retval FLAC__bool
  *    \c false if already at the first metadata block of the chain, else
  *    \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_prev(FLAC__Metadata_SimpleIterator *iterator);
 
 /** Get the type of the metadata block at the current position.  This
  *  avoids reading the actual block data which can save time for large
  *  blocks.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  * \retval FLAC__MetadataType
  *    The type of the metadata block at the current iterator position.
  */
 
 FLAC_API FLAC__MetadataType FLAC__metadata_simple_iterator_get_block_type(const FLAC__Metadata_SimpleIterator *iterator);
 
 /** Get the metadata block at the current position.  You can modify the
  *  block but must use FLAC__metadata_simple_iterator_set_block() to
  *  write it back to the FLAC file.
  *
  *  You must call FLAC__metadata_object_delete() on the returned object
  *  when you are finished with it.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  * \retval FLAC__StreamMetadata*
  *    The current metadata block.
  */
 FLAC_API FLAC__StreamMetadata *FLAC__metadata_simple_iterator_get_block(FLAC__Metadata_SimpleIterator *iterator);
 
 /** Write a block back to the FLAC file.  This function tries to be
  *  as efficient as possible; how the block is actually written is
  *  shown by the following:
  *
  *  Existing block is a STREAMINFO block and the new block is a
  *  STREAMINFO block: the new block is written in place.  Make sure
  *  you know what you're doing when changing the values of a
  *  STREAMINFO block.
  *
  *  Existing block is a STREAMINFO block and the new block is a
  *  not a STREAMINFO block: this is an error since the first block
  *  must be a STREAMINFO block.  Returns \c false without altering the
  *  file.
  *
  *  Existing block is not a STREAMINFO block and the new block is a
  *  STREAMINFO block: this is an error since there may be only one
  *  STREAMINFO block.  Returns \c false without altering the file.
  *
  *  Existing block and new block are the same length: the existing
  *  block will be replaced by the new block, written in place.
  *
  *  Existing block is longer than new block: if use_padding is \c true,
  *  the existing block will be overwritten in place with the new
  *  block followed by a PADDING block, if possible, to make the total
  *  size the same as the existing block.  Remember that a padding
  *  block requires at least four bytes so if the difference in size
  *  between the new block and existing block is less than that, the
  *  entire file will have to be rewritten, using the new block's
  *  exact size.  If use_padding is \c false, the entire file will be
  *  rewritten, replacing the existing block by the new block.
  *
  *  Existing block is shorter than new block: if use_padding is \c true,
  *  the function will try and expand the new block into the following
  *  PADDING block, if it exists and doing so won't shrink the PADDING
  *  block to less than 4 bytes.  If there is no following PADDING
  *  block, or it will shrink to less than 4 bytes, or use_padding is
  *  \c false, the entire file is rewritten, replacing the existing block
  *  with the new block.  Note that in this case any following PADDING
  *  block is preserved as is.
  *
  *  After writing the block, the iterator will remain in the same
  *  place, i.e. pointing to the new block.
  *
  * \param iterator     A pointer to an existing initialized iterator.
  * \param block        The block to set.
  * \param use_padding  See above.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  *    \code block != NULL \endcode
  * \retval FLAC__bool
  *    \c true if successful, else \c false.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_set_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
 
 /** This is similar to FLAC__metadata_simple_iterator_set_block()
  *  except that instead of writing over an existing block, it appends
  *  a block after the existing block.  \a use_padding is again used to
  *  tell the function to try an expand into following padding in an
  *  attempt to avoid rewriting the entire file.
  *
  *  This function will fail and return \c false if given a STREAMINFO
  *  block.
  *
  *  After writing the block, the iterator will be pointing to the
  *  new block.
  *
  * \param iterator     A pointer to an existing initialized iterator.
  * \param block        The block to set.
  * \param use_padding  See above.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  *    \code block != NULL \endcode
  * \retval FLAC__bool
  *    \c true if successful, else \c false.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_insert_block_after(FLAC__Metadata_SimpleIterator *iterator, FLAC__StreamMetadata *block, FLAC__bool use_padding);
 
 /** Deletes the block at the current position.  This will cause the
  *  entire FLAC file to be rewritten, unless \a use_padding is \c true,
  *  in which case the block will be replaced by an equal-sized PADDING
  *  block.  The iterator will be left pointing to the block before the
  *  one just deleted.
  *
  *  You may not delete the STREAMINFO block.
  *
  * \param iterator     A pointer to an existing initialized iterator.
  * \param use_padding  See above.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_simple_iterator_init()
  * \retval FLAC__bool
  *    \c true if successful, else \c false.
  */
 FLAC_API FLAC__bool FLAC__metadata_simple_iterator_delete_block(FLAC__Metadata_SimpleIterator *iterator, FLAC__bool use_padding);
 
 /* \} */
 
 
 /** \defgroup flac_metadata_level2 FLAC/metadata.h: metadata level 2 interface
  *  \ingroup flac_metadata
  *
  * \brief
  * The level 2 interface provides read-write access to FLAC file metadata;
  * all metadata is read into memory, operated on in memory, and then written
  * to file, which is more efficient than level 1 when editing multiple blocks.
  *
  * The general usage of this interface is:
  *
  * - Create a new chain using FLAC__metadata_chain_new().  A chain is a
  *   linked list of FLAC metadata blocks.
  * - Read all metadata into the the chain from a FLAC file using
  *   FLAC__metadata_chain_read() and check the status.
  * - Optionally, consolidate the padding using
  *   FLAC__metadata_chain_merge_padding() or
  *   FLAC__metadata_chain_sort_padding().
  * - Create a new iterator using FLAC__metadata_iterator_new()
  * - Initialize the iterator to point to the first element in the chain
  *   using FLAC__metadata_iterator_init()
  * - Traverse the chain using FLAC__metadata_iterator_next and
  *   FLAC__metadata_iterator_prev().
  * - Get a block for reading or modification using
  *   FLAC__metadata_iterator_get_block().  The pointer to the object
  *   inside the chain is returned, so the block is yours to modify.
  *   Changes will be reflected in the FLAC file when you write the
  *   chain.  You can also add and delete blocks (see functions below).
  * - When done, write out the chain using FLAC__metadata_chain_write().
  *   Make sure to read the whole comment to the function below.
  * - Delete the chain using FLAC__metadata_chain_delete().
  *
  * \note
  * Even though the FLAC file is not open while the chain is being
  * manipulated, you must not alter the file externally during
  * this time.  The chain assumes the FLAC file will not change
  * between the time of FLAC__metadata_chain_read() and
  * FLAC__metadata_chain_write().
  *
  * \note
  * Do not modify the is_last, length, or type fields of returned
  * FLAC__StreamMetadata objects.  These are managed automatically.
  *
  * \note
  * The metadata objects returned by FLAC__metadata_iterator_get_block()
  * are owned by the chain; do not FLAC__metadata_object_delete() them.
  * In the same way, blocks passed to FLAC__metadata_iterator_set_block()
  * become owned by the chain and they will be deleted when the chain is
  * deleted.
  *
  * \{
  */
 
 struct FLAC__Metadata_Chain;
 /** The opaque structure definition for the level 2 chain type.
  */
 typedef struct FLAC__Metadata_Chain FLAC__Metadata_Chain;
 
 struct FLAC__Metadata_Iterator;
 /** The opaque structure definition for the level 2 iterator type.
  */
 typedef struct FLAC__Metadata_Iterator FLAC__Metadata_Iterator;
 
 typedef enum {
 	FLAC__METADATA_CHAIN_STATUS_OK = 0,
 	/**< The chain is in the normal OK state */
 
 	FLAC__METADATA_CHAIN_STATUS_ILLEGAL_INPUT,
 	/**< The data passed into a function violated the function's usage criteria */
 
 	FLAC__METADATA_CHAIN_STATUS_ERROR_OPENING_FILE,
 	/**< The chain could not open the target file */
 
 	FLAC__METADATA_CHAIN_STATUS_NOT_A_FLAC_FILE,
 	/**< The chain could not find the FLAC signature at the start of the file */
 
 	FLAC__METADATA_CHAIN_STATUS_NOT_WRITABLE,
 	/**< The chain tried to write to a file that was not writable */
 
 	FLAC__METADATA_CHAIN_STATUS_BAD_METADATA,
 	/**< The chain encountered input that does not conform to the FLAC metadata specification */
 
 	FLAC__METADATA_CHAIN_STATUS_READ_ERROR,
 	/**< The chain encountered an error while reading the FLAC file */
 
 	FLAC__METADATA_CHAIN_STATUS_SEEK_ERROR,
 	/**< The chain encountered an error while seeking in the FLAC file */
 
 	FLAC__METADATA_CHAIN_STATUS_WRITE_ERROR,
 	/**< The chain encountered an error while writing the FLAC file */
 
 	FLAC__METADATA_CHAIN_STATUS_RENAME_ERROR,
 	/**< The chain encountered an error renaming the FLAC file */
 
 	FLAC__METADATA_CHAIN_STATUS_UNLINK_ERROR,
 	/**< The chain encountered an error removing the temporary file */
 
 	FLAC__METADATA_CHAIN_STATUS_MEMORY_ALLOCATION_ERROR,
 	/**< Memory allocation failed */
 
 	FLAC__METADATA_CHAIN_STATUS_INTERNAL_ERROR,
 	/**< The caller violated an assertion or an unexpected error occurred */
 
 	FLAC__METADATA_CHAIN_STATUS_INVALID_CALLBACKS,
 	/**< One or more of the required callbacks was NULL */
 
 	FLAC__METADATA_CHAIN_STATUS_READ_WRITE_MISMATCH,
 	/**< FLAC__metadata_chain_write() was called on a chain read by
 	 *   FLAC__metadata_chain_read_with_callbacks(), or
 	 *   FLAC__metadata_chain_write_with_callbacks() or
 	 *   FLAC__metadata_chain_write_with_callbacks_and_tempfile() was
 	 *   called on a chain read by FLAC__metadata_chain_read().  Matching
 	 *   read/write methods must always be used. */
 
 	FLAC__METADATA_CHAIN_STATUS_WRONG_WRITE_CALL
 	/**< FLAC__metadata_chain_write_with_callbacks() was called when the
 	 *   chain write requires a tempfile; use
 	 *   FLAC__metadata_chain_write_with_callbacks_and_tempfile() instead.
 	 *   Or, FLAC__metadata_chain_write_with_callbacks_and_tempfile() was
 	 *   called when the chain write does not require a tempfile; use
 	 *   FLAC__metadata_chain_write_with_callbacks() instead.
 	 *   Always check FLAC__metadata_chain_check_if_tempfile_needed()
 	 *   before writing via callbacks. */
 
 } FLAC__Metadata_ChainStatus;
 
 /** Maps a FLAC__Metadata_ChainStatus to a C string.
  *
  *  Using a FLAC__Metadata_ChainStatus as the index to this array
  *  will give the string equivalent.  The contents should not be modified.
  */
 extern FLAC_API const char * const FLAC__Metadata_ChainStatusString[];
 
 /*********** FLAC__Metadata_Chain ***********/
 
 /** Create a new chain instance.
  *
  * \retval FLAC__Metadata_Chain*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__Metadata_Chain *FLAC__metadata_chain_new();
 
 /** Free a chain instance.  Deletes the object pointed to by \a chain.
  *
  * \param chain  A pointer to an existing chain.
  * \assert
  *    \code chain != NULL \endcode
  */
 FLAC_API void FLAC__metadata_chain_delete(FLAC__Metadata_Chain *chain);
 
 /** Get the current status of the chain.  Call this after a function
  *  returns \c false to get the reason for the error.  Also resets the
  *  status to FLAC__METADATA_CHAIN_STATUS_OK.
  *
  * \param chain    A pointer to an existing chain.
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__Metadata_ChainStatus
  *    The current status of the chain.
  */
 FLAC_API FLAC__Metadata_ChainStatus FLAC__metadata_chain_status(FLAC__Metadata_Chain *chain);
 
 /** Read all metadata from a FLAC file into the chain.
  *
  * \param chain    A pointer to an existing chain.
  * \param filename The path to the FLAC file to read.
  * \assert
  *    \code chain != NULL \endcode
  *    \code filename != NULL \endcode
  * \retval FLAC__bool
  *    \c true if a valid list of metadata blocks was read from
  *    \a filename, else \c false.  On failure, check the status with
  *    FLAC__metadata_chain_status().
  */
 FLAC_API FLAC__bool FLAC__metadata_chain_read(FLAC__Metadata_Chain *chain, const char *filename);
 
 /** Read all metadata from a FLAC stream into the chain via I/O callbacks.
  *
  *  The \a handle need only be open for reading, but must be seekable.
  *  The equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
  *  for Windows).
  *
  * \param chain    A pointer to an existing chain.
  * \param handle   The I/O handle of the FLAC stream to read.  The
  *                 handle will NOT be closed after the metadata is read;
  *                 that is the duty of the caller.
  * \param callbacks
  *                 A set of callbacks to use for I/O.  The mandatory
  *                 callbacks are \a read, \a seek, and \a tell.
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__bool
  *    \c true if a valid list of metadata blocks was read from
  *    \a handle, else \c false.  On failure, check the status with
  *    FLAC__metadata_chain_status().
  */
 FLAC_API FLAC__bool FLAC__metadata_chain_read_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
 
 /** Checks if writing the given chain would require the use of a
  *  temporary file, or if it could be written in place.
  *
  *  Under certain conditions, padding can be utilized so that writing
  *  edited metadata back to the FLAC file does not require rewriting the
  *  entire file.  If rewriting is required, then a temporary workfile is
  *  required.  When writing metadata using callbacks, you must check
  *  this function to know whether to call
  *  FLAC__metadata_chain_write_with_callbacks() or
  *  FLAC__metadata_chain_write_with_callbacks_and_tempfile().  When
  *  writing with FLAC__metadata_chain_write(), the temporary file is
  *  handled internally.
  *
  * \param chain    A pointer to an existing chain.
  * \param use_padding
  *                 Whether or not padding will be allowed to be used
  *                 during the write.  The value of \a use_padding given
  *                 here must match the value later passed to
  *                 FLAC__metadata_chain_write_with_callbacks() or
  *                 FLAC__metadata_chain_write_with_callbacks_with_tempfile().
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__bool
  *    \c true if writing the current chain would require a tempfile, or
  *    \c false if metadata can be written in place.
  */
 FLAC_API FLAC__bool FLAC__metadata_chain_check_if_tempfile_needed(FLAC__Metadata_Chain *chain, FLAC__bool use_padding);
 
 /** Write all metadata out to the FLAC file.  This function tries to be as
  *  efficient as possible; how the metadata is actually written is shown by
  *  the following:
  *
  *  If the current chain is the same size as the existing metadata, the new
  *  data is written in place.
  *
  *  If the current chain is longer than the existing metadata, and
  *  \a use_padding is \c true, and the last block is a PADDING block of
  *  sufficient length, the function will truncate the final padding block
  *  so that the overall size of the metadata is the same as the existing
  *  metadata, and then just rewrite the metadata.  Otherwise, if not all of
  *  the above conditions are met, the entire FLAC file must be rewritten.
  *  If you want to use padding this way it is a good idea to call
  *  FLAC__metadata_chain_sort_padding() first so that you have the maximum
  *  amount of padding to work with, unless you need to preserve ordering
  *  of the PADDING blocks for some reason.
  *
  *  If the current chain is shorter than the existing metadata, and
  *  \a use_padding is \c true, and the final block is a PADDING block, the padding
  *  is extended to make the overall size the same as the existing data.  If
  *  \a use_padding is \c true and the last block is not a PADDING block, a new
  *  PADDING block is added to the end of the new data to make it the same
  *  size as the existing data (if possible, see the note to
  *  FLAC__metadata_simple_iterator_set_block() about the four byte limit)
  *  and the new data is written in place.  If none of the above apply or
  *  \a use_padding is \c false, the entire FLAC file is rewritten.
  *
  *  If \a preserve_file_stats is \c true, the owner and modification time will
  *  be preserved even if the FLAC file is written.
  *
  *  For this write function to be used, the chain must have been read with
  *  FLAC__metadata_chain_read(), not FLAC__metadata_chain_read_with_callbacks().
  *
  * \param chain               A pointer to an existing chain.
  * \param use_padding         See above.
  * \param preserve_file_stats See above.
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__bool
  *    \c true if the write succeeded, else \c false.  On failure,
  *    check the status with FLAC__metadata_chain_status().
  */
 FLAC_API FLAC__bool FLAC__metadata_chain_write(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__bool preserve_file_stats);
 
 /** Write all metadata out to a FLAC stream via callbacks.
  *
  *  (See FLAC__metadata_chain_write() for the details on how padding is
  *  used to write metadata in place if possible.)
  *
  *  The \a handle must be open for updating and be seekable.  The
  *  equivalent minimum stdio fopen() file mode is \c "r+" (or \c "r+b"
  *  for Windows).
  *
  *  For this write function to be used, the chain must have been read with
  *  FLAC__metadata_chain_read_with_callbacks(), not FLAC__metadata_chain_read().
  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
  *  \c false.
  *
  * \param chain        A pointer to an existing chain.
  * \param use_padding  See FLAC__metadata_chain_write()
  * \param handle       The I/O handle of the FLAC stream to write.  The
  *                     handle will NOT be closed after the metadata is
  *                     written; that is the duty of the caller.
  * \param callbacks    A set of callbacks to use for I/O.  The mandatory
  *                     callbacks are \a write and \a seek.
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__bool
  *    \c true if the write succeeded, else \c false.  On failure,
  *    check the status with FLAC__metadata_chain_status().
  */
 FLAC_API FLAC__bool FLAC__metadata_chain_write_with_callbacks(FLAC__Metadata_Chain *chain, FLAC__bool use_padding, FLAC__IOHandle handle, FLAC__IOCallbacks callbacks);
 
 /** Write all metadata out to a FLAC stream via callbacks.
  *
  *  (See FLAC__metadata_chain_write() for the details on how padding is
  *  used to write metadata in place if possible.)
  *
  *  This version of the write-with-callbacks function must be used when
  *  FLAC__metadata_chain_check_if_tempfile_needed() returns true.  In
  *  this function, you must supply an I/O handle corresponding to the
  *  FLAC file to edit, and a temporary handle to which the new FLAC
  *  file will be written.  It is the caller's job to move this temporary
  *  FLAC file on top of the original FLAC file to complete the metadata
  *  edit.
  *
  *  The \a handle must be open for reading and be seekable.  The
  *  equivalent minimum stdio fopen() file mode is \c "r" (or \c "rb"
  *  for Windows).
  *
  *  The \a temp_handle must be open for writing.  The
  *  equivalent minimum stdio fopen() file mode is \c "w" (or \c "wb"
  *  for Windows).  It should be an empty stream, or at least positioned
  *  at the start-of-file (in which case it is the caller's duty to
  *  truncate it on return).
  *
  *  For this write function to be used, the chain must have been read with
  *  FLAC__metadata_chain_read_with_callbacks(), not FLAC__metadata_chain_read().
  *  Also, FLAC__metadata_chain_check_if_tempfile_needed() must have returned
  *  \c true.
  *
  * \param chain        A pointer to an existing chain.
  * \param use_padding  See FLAC__metadata_chain_write()
  * \param handle       The I/O handle of the original FLAC stream to read.
  *                     The handle will NOT be closed after the metadata is
  *                     written; that is the duty of the caller.
  * \param callbacks    A set of callbacks to use for I/O on \a handle.
  *                     The mandatory callbacks are \a read, \a seek, and
  *                     \a eof.
  * \param temp_handle  The I/O handle of the FLAC stream to write.  The
  *                     handle will NOT be closed after the metadata is
  *                     written; that is the duty of the caller.
  * \param temp_callbacks
  *                     A set of callbacks to use for I/O on temp_handle.
  *                     The only mandatory callback is \a write.
  * \assert
  *    \code chain != NULL \endcode
  * \retval FLAC__bool
  *    \c true if the write succeeded, else \c false.  On failure,
  *    check the status with FLAC__metadata_chain_status().
  */
 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);
 
 /** Merge adjacent PADDING blocks into a single block.
  *
  * \note This function does not write to the FLAC file, it only
  * modifies the chain.
  *
  * \warning Any iterator on the current chain will become invalid after this
  * call.  You should delete the iterator and get a new one.
  *
  * \param chain               A pointer to an existing chain.
  * \assert
  *    \code chain != NULL \endcode
  */
 FLAC_API void FLAC__metadata_chain_merge_padding(FLAC__Metadata_Chain *chain);
 
 /** This function will move all PADDING blocks to the end on the metadata,
  *  then merge them into a single block.
  *
  * \note This function does not write to the FLAC file, it only
  * modifies the chain.
  *
  * \warning Any iterator on the current chain will become invalid after this
  * call.  You should delete the iterator and get a new one.
  *
  * \param chain  A pointer to an existing chain.
  * \assert
  *    \code chain != NULL \endcode
  */
 FLAC_API void FLAC__metadata_chain_sort_padding(FLAC__Metadata_Chain *chain);
 
 
 /*********** FLAC__Metadata_Iterator ***********/
 
 /** Create a new iterator instance.
  *
  * \retval FLAC__Metadata_Iterator*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__Metadata_Iterator *FLAC__metadata_iterator_new();
 
 /** Free an iterator instance.  Deletes the object pointed to by \a iterator.
  *
  * \param iterator  A pointer to an existing iterator.
  * \assert
  *    \code iterator != NULL \endcode
  */
 FLAC_API void FLAC__metadata_iterator_delete(FLAC__Metadata_Iterator *iterator);
 
 /** Initialize the iterator to point to the first metadata block in the
  *  given chain.
  *
  * \param iterator  A pointer to an existing iterator.
  * \param chain     A pointer to an existing and initialized (read) chain.
  * \assert
  *    \code iterator != NULL \endcode
  *    \code chain != NULL \endcode
  */
 FLAC_API void FLAC__metadata_iterator_init(FLAC__Metadata_Iterator *iterator, FLAC__Metadata_Chain *chain);
 
 /** Moves the iterator forward one metadata block, returning \c false if
  *  already at the end.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__bool
  *    \c false if already at the last metadata block of the chain, else
  *    \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_next(FLAC__Metadata_Iterator *iterator);
 
 /** Moves the iterator backward one metadata block, returning \c false if
  *  already at the beginning.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__bool
  *    \c false if already at the first metadata block of the chain, else
  *    \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_prev(FLAC__Metadata_Iterator *iterator);
 
 /** Get the type of the metadata block at the current position.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__MetadataType
  *    The type of the metadata block at the current iterator position.
  */
 FLAC_API FLAC__MetadataType FLAC__metadata_iterator_get_block_type(const FLAC__Metadata_Iterator *iterator);
 
 /** Get the metadata block at the current position.  You can modify
  *  the block in place but must write the chain before the changes
  *  are reflected to the FLAC file.  You do not need to call
  *  FLAC__metadata_iterator_set_block() to reflect the changes;
  *  the pointer returned by FLAC__metadata_iterator_get_block()
  *  points directly into the chain.
  *
  * \warning
  * Do not call FLAC__metadata_object_delete() on the returned object;
  * to delete a block use FLAC__metadata_iterator_delete_block().
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__StreamMetadata*
  *    The current metadata block.
  */
 FLAC_API FLAC__StreamMetadata *FLAC__metadata_iterator_get_block(FLAC__Metadata_Iterator *iterator);
 
 /** Set the metadata block at the current position, replacing the existing
  *  block.  The new block passed in becomes owned by the chain and it will be
  *  deleted when the chain is deleted.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \param block     A pointer to a metadata block.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  *    \code block != NULL \endcode
  * \retval FLAC__bool
  *    \c false if the conditions in the above description are not met, or
  *    a memory allocation error occurs, otherwise \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_set_block(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
 
 /** Removes the current block from the chain.  If \a replace_with_padding is
  *  \c true, the block will instead be replaced with a padding block of equal
  *  size.  You can not delete the STREAMINFO block.  The iterator will be
  *  left pointing to the block before the one just "deleted", even if
  *  \a replace_with_padding is \c true.
  *
  * \param iterator              A pointer to an existing initialized iterator.
  * \param replace_with_padding  See above.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__bool
  *    \c false if the conditions in the above description are not met,
  *    otherwise \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_delete_block(FLAC__Metadata_Iterator *iterator, FLAC__bool replace_with_padding);
 
 /** Insert a new block before the current block.  You cannot insert a block
  *  before the first STREAMINFO block.  You cannot insert a STREAMINFO block
  *  as there can be only one, the one that already exists at the head when you
  *  read in a chain.  The chain takes ownership of the new block and it will be
  *  deleted when the chain is deleted.  The iterator will be left pointing to
  *  the new block.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \param block     A pointer to a metadata block to insert.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__bool
  *    \c false if the conditions in the above description are not met, or
  *    a memory allocation error occurs, otherwise \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_before(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
 
 /** Insert a new block after the current block.  You cannot insert a STREAMINFO
  *  block as there can be only one, the one that already exists at the head when
  *  you read in a chain.  The chain takes ownership of the new block and it will
  *  be deleted when the chain is deleted.  The iterator will be left pointing to
  *  the new block.
  *
  * \param iterator  A pointer to an existing initialized iterator.
  * \param block     A pointer to a metadata block to insert.
  * \assert
  *    \code iterator != NULL \endcode
  *    \a iterator has been successfully initialized with
  *    FLAC__metadata_iterator_init()
  * \retval FLAC__bool
  *    \c false if the conditions in the above description are not met, or
  *    a memory allocation error occurs, otherwise \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_iterator_insert_block_after(FLAC__Metadata_Iterator *iterator, FLAC__StreamMetadata *block);
 
 /* \} */
 
 
 /** \defgroup flac_metadata_object FLAC/metadata.h: metadata object methods
  *  \ingroup flac_metadata
  *
  * \brief
  * This module contains methods for manipulating FLAC metadata objects.
  *
  * Since many are variable length we have to be careful about the memory
  * management.  We decree that all pointers to data in the object are
  * owned by the object and memory-managed by the object.
  *
  * Use the FLAC__metadata_object_new() and FLAC__metadata_object_delete()
  * functions to create all instances.  When using the
  * FLAC__metadata_object_set_*() functions to set pointers to data, set
  * \a copy to \c true to have the function make it's own copy of the data, or
  * to \c false to give the object ownership of your data.  In the latter case
  * your pointer must be freeable by free() and will be free()d when the object
  * is FLAC__metadata_object_delete()d.  It is legal to pass a null pointer as
  * the data pointer to a FLAC__metadata_object_set_*() function as long as
  * the length argument is 0 and the \a copy argument is \c false.
  *
  * The FLAC__metadata_object_new() and FLAC__metadata_object_clone() function
  * will return \c NULL in the case of a memory allocation error, otherwise a new
  * object.  The FLAC__metadata_object_set_*() functions return \c false in the
  * case of a memory allocation error.
  *
  * We don't have the convenience of C++ here, so note that the library relies
  * on you to keep the types straight.  In other words, if you pass, for
  * example, a FLAC__StreamMetadata* that represents a STREAMINFO block to
  * FLAC__metadata_object_application_set_data(), you will get an assertion
  * failure.
  *
  * For convenience the FLAC__metadata_object_vorbiscomment_*() functions
  * maintain a trailing NUL on each Vorbis comment entry.  This is not counted
  * toward the length or stored in the stream, but it can make working with plain
  * comments (those that don't contain embedded-NULs in the value) easier.
  * Entries passed into these functions have trailing NULs added if missing, and
  * returned entries are guaranteed to have a trailing NUL.
  *
  * The FLAC__metadata_object_vorbiscomment_*() functions that take a Vorbis
  * comment entry/name/value will first validate that it complies with the Vorbis
  * comment specification and return false if it does not.
  *
  * There is no need to recalculate the length field on metadata blocks you
  * have modified.  They will be calculated automatically before they  are
  * written back to a file.
  *
  * \{
  */
 
 
 /** Create a new metadata object instance of the given type.
  *
  *  The object will be "empty"; i.e. values and data pointers will be \c 0,
  *  with the exception of FLAC__METADATA_TYPE_VORBIS_COMMENT, which will have
  *  the vendor string set (but zero comments).
  *
  *  Do not pass in a value greater than or equal to
  *  \a FLAC__METADATA_TYPE_UNDEFINED unless you really know what you're
  *  doing.
  *
  * \param type  Type of object to create
  * \retval FLAC__StreamMetadata*
  *    \c NULL if there was an error allocating memory or the type code is
  *    greater than FLAC__MAX_METADATA_TYPE_CODE, else the new instance.
  */
 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_new(FLAC__MetadataType type);
 
 /** Create a copy of an existing metadata object.
  *
  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
  *  object is also copied.  The caller takes ownership of the new block and
  *  is responsible for freeing it with FLAC__metadata_object_delete().
  *
  * \param object  Pointer to object to copy.
  * \assert
  *    \code object != NULL \endcode
  * \retval FLAC__StreamMetadata*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_clone(const FLAC__StreamMetadata *object);
 
 /** Free a metadata object.  Deletes the object pointed to by \a object.
  *
  *  The delete is a "deep" delete, i.e. dynamically allocated data within the
  *  object is also deleted.
  *
  * \param object  A pointer to an existing object.
  * \assert
  *    \code object != NULL \endcode
  */
 FLAC_API void FLAC__metadata_object_delete(FLAC__StreamMetadata *object);
 
 /** Compares two metadata objects.
  *
  *  The compare is "deep", i.e. dynamically allocated data within the
  *  object is also compared.
  *
  * \param block1  A pointer to an existing object.
  * \param block2  A pointer to an existing object.
  * \assert
  *    \code block1 != NULL \endcode
  *    \code block2 != NULL \endcode
  * \retval FLAC__bool
  *    \c true if objects are identical, else \c false.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_is_equal(const FLAC__StreamMetadata *block1, const FLAC__StreamMetadata *block2);
 
 /** Sets the application data of an APPLICATION block.
  *
  *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
  *  takes ownership of the pointer.
  *
  * \param object  A pointer to an existing APPLICATION object.
  * \param data    A pointer to the data to set.
  * \param length  The length of \a data in bytes.
  * \param copy    See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_APPLICATION \endcode
  *    \code (data != NULL && length > 0) ||
  * (data == NULL && length == 0 && copy == false) \endcode
  * \retval FLAC__bool
  *    \c false if \a copy is \c true and malloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, unsigned length, FLAC__bool copy);
 
 /** Resize the seekpoint array.
  *
  *  If the size shrinks, elements will truncated; if it grows, new placeholder
  *  points will be added to the end.
  *
  * \param object          A pointer to an existing SEEKTABLE object.
  * \param new_num_points  The desired length of the array; may be \c 0.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  *    \code (object->data.seek_table.points == NULL && object->data.seek_table.num_points == 0) ||
  * (object->data.seek_table.points != NULL && object->data.seek_table.num_points > 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation error, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_resize_points(FLAC__StreamMetadata *object, unsigned new_num_points);
 
 /** Set a seekpoint in a seektable.
  *
  * \param object     A pointer to an existing SEEKTABLE object.
  * \param point_num  Index into seekpoint array to set.
  * \param point      The point to set.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  *    \code object->data.seek_table.num_points > point_num \endcode
  */
 FLAC_API void FLAC__metadata_object_seektable_set_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
 
 /** Insert a seekpoint into a seektable.
  *
  * \param object     A pointer to an existing SEEKTABLE object.
  * \param point_num  Index into seekpoint array to set.
  * \param point      The point to set.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  *    \code object->data.seek_table.num_points >= point_num \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation error, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_insert_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point);
 
 /** Delete a seekpoint from a seektable.
  *
  * \param object     A pointer to an existing SEEKTABLE object.
  * \param point_num  Index into seekpoint array to set.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  *    \code object->data.seek_table.num_points > point_num \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation error, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_delete_point(FLAC__StreamMetadata *object, unsigned point_num);
 
 /** Check a seektable to see if it conforms to the FLAC specification.
  *  See the format specification for limits on the contents of the
  *  seektable.
  *
  * \param object  A pointer to an existing SEEKTABLE object.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if seek table is illegal, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_is_legal(const FLAC__StreamMetadata *object);
 
 /** Append a number of placeholder points to the end of a seek table.
  *
  * \note
  * As with the other ..._seektable_template_... functions, you should
  * call FLAC__metadata_object_seektable_template_sort() when finished
  * to make the seek table legal.
  *
  * \param object  A pointer to an existing SEEKTABLE object.
  * \param num     The number of placeholder points to append.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_placeholders(FLAC__StreamMetadata *object, unsigned num);
 
 /** Append a specific seek point template to the end of a seek table.
  *
  * \note
  * As with the other ..._seektable_template_... functions, you should
  * call FLAC__metadata_object_seektable_template_sort() when finished
  * to make the seek table legal.
  *
  * \param object  A pointer to an existing SEEKTABLE object.
  * \param sample_number  The sample number of the seek point template.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_point(FLAC__StreamMetadata *object, FLAC__uint64 sample_number);
 
 /** Append specific seek point templates to the end of a seek table.
  *
  * \note
  * As with the other ..._seektable_template_... functions, you should
  * call FLAC__metadata_object_seektable_template_sort() when finished
  * to make the seek table legal.
  *
  * \param object  A pointer to an existing SEEKTABLE object.
  * \param sample_numbers  An array of sample numbers for the seek points.
  * \param num     The number of seek point templates to append.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_points(FLAC__StreamMetadata *object, FLAC__uint64 sample_numbers[], unsigned num);
 
 /** Append a set of evenly-spaced seek point templates to the end of a
  *  seek table.
  *
  * \note
  * As with the other ..._seektable_template_... functions, you should
  * call FLAC__metadata_object_seektable_template_sort() when finished
  * to make the seek table legal.
  *
  * \param object  A pointer to an existing SEEKTABLE object.
  * \param num     The number of placeholder points to append.
  * \param total_samples  The total number of samples to be encoded;
  *                       the seekpoints will be spaced approximately
  *                       \a total_samples / \a num samples apart.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points(FLAC__StreamMetadata *object, unsigned num, FLAC__uint64 total_samples);
 
 /** Sort a seek table's seek points according to the format specification,
  *  removing duplicates.
  *
  * \param object   A pointer to a seek table to be sorted.
  * \param compact  If \c false, behaves like FLAC__format_seektable_sort().
  *                 If \c true, duplicates are deleted and the seek table is
  *                 shrunk appropriately; the number of placeholder points
  *                 present in the seek table will be the same after the call
  *                 as before.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_sort(FLAC__StreamMetadata *object, FLAC__bool compact);
 
 /** Sets the vendor string in a VORBIS_COMMENT block.
  *
  *  For convenience, a trailing NUL is added to the entry if it doesn't have
  *  one already.
  *
  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
  *  takes ownership of the \c entry.entry pointer.
  *
  *  \note If this function returns \c false, the caller still owns the
  *  pointer.
  *
  * \param object  A pointer to an existing VORBIS_COMMENT object.
  * \param entry   The entry to set the vendor string to.
  * \param copy    See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code (entry.entry != NULL && entry.length > 0) ||
  * (entry.entry == NULL && entry.length == 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
 
 /** Resize the comment array.
  *
  *  If the size shrinks, elements will truncated; if it grows, new empty
  *  fields will be added to the end.
  *
  * \param object            A pointer to an existing VORBIS_COMMENT object.
  * \param new_num_comments  The desired length of the array; may be \c 0.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code (object->data.vorbis_comment.comments == NULL && object->data.vorbis_comment.num_comments == 0) ||
  * (object->data.vorbis_comment.comments != NULL && object->data.vorbis_comment.num_comments > 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_resize_comments(FLAC__StreamMetadata *object, unsigned new_num_comments);
 
 /** Sets a comment in a VORBIS_COMMENT block.
  *
  *  For convenience, a trailing NUL is added to the entry if it doesn't have
  *  one already.
  *
  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
  *  takes ownership of the \c entry.entry pointer.
  *
  *  \note If this function returns \c false, the caller still owns the
  *  pointer.
  *
  * \param object       A pointer to an existing VORBIS_COMMENT object.
  * \param comment_num  Index into comment array to set.
  * \param entry        The entry to set the comment to.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code comment_num < object->data.vorbis_comment.num_comments \endcode
  *    \code (entry.entry != NULL && entry.length > 0) ||
  * (entry.entry == NULL && entry.length == 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
 
 /** Insert a comment in a VORBIS_COMMENT block at the given index.
  *
  *  For convenience, a trailing NUL is added to the entry if it doesn't have
  *  one already.
  *
  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
  *  takes ownership of the \c entry.entry pointer.
  *
  *  \note If this function returns \c false, the caller still owns the
  *  pointer.
  *
  * \param object       A pointer to an existing VORBIS_COMMENT object.
  * \param comment_num  The index at which to insert the comment.  The comments
  *                     at and after \a comment_num move right one position.
  *                     To append a comment to the end, set \a comment_num to
  *                     \c object->data.vorbis_comment.num_comments .
  * \param entry        The comment to insert.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code object->data.vorbis_comment.num_comments >= comment_num \endcode
  *    \code (entry.entry != NULL && entry.length > 0) ||
  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_insert_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
 
 /** Appends a comment to a VORBIS_COMMENT block.
  *
  *  For convenience, a trailing NUL is added to the entry if it doesn't have
  *  one already.
  *
  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
  *  takes ownership of the \c entry.entry pointer.
  *
  *  \note If this function returns \c false, the caller still owns the
  *  pointer.
  *
  * \param object       A pointer to an existing VORBIS_COMMENT object.
  * \param entry        The comment to insert.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code (entry.entry != NULL && entry.length > 0) ||
  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_append_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy);
 
 /** Replaces comments in a VORBIS_COMMENT block with a new one.
  *
  *  For convenience, a trailing NUL is added to the entry if it doesn't have
  *  one already.
  *
  *  Depending on the the value of \a all, either all or just the first comment
  *  whose field name(s) match the given entry's name will be replaced by the
  *  given entry.  If no comments match, \a entry will simply be appended.
  *
  *  If \a copy is \c true, a copy of the entry is stored; otherwise, the object
  *  takes ownership of the \c entry.entry pointer.
  *
  *  \note If this function returns \c false, the caller still owns the
  *  pointer.
  *
  * \param object       A pointer to an existing VORBIS_COMMENT object.
  * \param entry        The comment to insert.
  * \param all          If \c true, all comments whose field name matches
  *                     \a entry's field name will be removed, and \a entry will
  *                     be inserted at the position of the first matching
  *                     comment.  If \c false, only the first comment whose
  *                     field name matches \a entry's field name will be
  *                     replaced with \a entry.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code (entry.entry != NULL && entry.length > 0) ||
  * (entry.entry == NULL && entry.length == 0 && copy == false) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_replace_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool all, FLAC__bool copy);
 
 /** Delete a comment in a VORBIS_COMMENT block at the given index.
  *
  * \param object       A pointer to an existing VORBIS_COMMENT object.
  * \param comment_num  The index of the comment to delete.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code object->data.vorbis_comment.num_comments > comment_num \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_delete_comment(FLAC__StreamMetadata *object, unsigned comment_num);
 
 /** Creates a Vorbis comment entry from NUL-terminated name and value strings.
  *
  *  On return, the filled-in \a entry->entry pointer will point to malloc()ed
  *  memory and shall be owned by the caller.  For convenience the entry will
  *  have a terminating NUL.
  *
  * \param entry              A pointer to a Vorbis comment entry.  The entry's
  *                           \c entry pointer should not point to allocated
  *                           memory as it will be overwritten.
  * \param field_name         The field name in ASCII, \c NUL terminated.
  * \param field_value        The field value in UTF-8, \c NUL terminated.
  * \assert
  *    \code entry != NULL \endcode
  *    \code field_name != NULL \endcode
  *    \code field_value != NULL \endcode
  * \retval FLAC__bool
  *    \c false if malloc() fails, or if \a field_name or \a field_value does
  *    not comply with the Vorbis comment specification, else \c true.
  */
 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);
 
 /** Splits a Vorbis comment entry into NUL-terminated name and value strings.
  *
  *  The returned pointers to name and value will be allocated by malloc()
  *  and shall be owned by the caller.
  *
  * \param entry              An existing Vorbis comment entry.
  * \param field_name         The address of where the returned pointer to the
  *                           field name will be stored.
  * \param field_value        The address of where the returned pointer to the
  *                           field value will be stored.
  * \assert
  *    \code (entry.entry != NULL && entry.length > 0) \endcode
  *    \code memchr(entry.entry, '=', entry.length) != NULL \endcode
  *    \code field_name != NULL \endcode
  *    \code field_value != NULL \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation fails or \a entry does not comply with the
  *    Vorbis comment specification, else \c true.
  */
 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);
 
 /** Check if the given Vorbis comment entry's field name matches the given
  *  field name.
  *
  * \param entry              An existing Vorbis comment entry.
  * \param field_name         The field name to check.
  * \param field_name_length  The length of \a field_name, not including the
  *                           terminating \c NUL.
  * \assert
  *    \code (entry.entry != NULL && entry.length > 0) \endcode
  * \retval FLAC__bool
  *    \c true if the field names match, else \c false
  */
 FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_matches(const FLAC__StreamMetadata_VorbisComment_Entry entry, const char *field_name, unsigned field_name_length);
 
 /** Find a Vorbis comment with the given field name.
  *
  *  The search begins at entry number \a offset; use an offset of 0 to
  *  search from the beginning of the comment array.
  *
  * \param object      A pointer to an existing VORBIS_COMMENT object.
  * \param offset      The offset into the comment array from where to start
  *                    the search.
  * \param field_name  The field name of the comment to find.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  *    \code field_name != NULL \endcode
  * \retval int
  *    The offset in the comment array of the first comment whose field
  *    name matches \a field_name, or \c -1 if no match was found.
  */
 FLAC_API int FLAC__metadata_object_vorbiscomment_find_entry_from(const FLAC__StreamMetadata *object, unsigned offset, const char *field_name);
 
 /** Remove first Vorbis comment matching the given field name.
  *
  * \param object      A pointer to an existing VORBIS_COMMENT object.
  * \param field_name  The field name of comment to delete.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  * \retval int
  *    \c -1 for memory allocation error, \c 0 for no matching entries,
  *    \c 1 for one matching entry deleted.
  */
 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entry_matching(FLAC__StreamMetadata *object, const char *field_name);
 
 /** Remove all Vorbis comments matching the given field name.
  *
  * \param object      A pointer to an existing VORBIS_COMMENT object.
  * \param field_name  The field name of comments to delete.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT \endcode
  * \retval int
  *    \c -1 for memory allocation error, \c 0 for no matching entries,
  *    else the number of matching entries deleted.
  */
 FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entries_matching(FLAC__StreamMetadata *object, const char *field_name);
 
 /** Create a new CUESHEET track instance.
  *
  *  The object will be "empty"; i.e. values and data pointers will be \c 0.
  *
  * \retval FLAC__StreamMetadata_CueSheet_Track*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_new();
 
 /** Create a copy of an existing CUESHEET track object.
  *
  *  The copy is a "deep" copy, i.e. dynamically allocated data within the
  *  object is also copied.  The caller takes ownership of the new object and
  *  is responsible for freeing it with
  *  FLAC__metadata_object_cuesheet_track_delete().
  *
  * \param object  Pointer to object to copy.
  * \assert
  *    \code object != NULL \endcode
  * \retval FLAC__StreamMetadata_CueSheet_Track*
  *    \c NULL if there was an error allocating memory, else the new instance.
  */
 FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_clone(const FLAC__StreamMetadata_CueSheet_Track *object);
 
 /** Delete a CUESHEET track object
  *
  * \param object       A pointer to an existing CUESHEET track object.
  * \assert
  *    \code object != NULL \endcode
  */
 FLAC_API void FLAC__metadata_object_cuesheet_track_delete(FLAC__StreamMetadata_CueSheet_Track *object);
 
 /** Resize a track's index point array.
  *
  *  If the size shrinks, elements will truncated; if it grows, new blank
  *  indices will be added to the end.
  *
  * \param object           A pointer to an existing CUESHEET object.
  * \param track_num        The index of the track to modify.  NOTE: this is not
  *                         necessarily the same as the track's \a number field.
  * \param new_num_indices  The desired length of the array; may be \c 0.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
  *    \code (object->data.cue_sheet.tracks[track_num].indices == NULL && object->data.cue_sheet.tracks[track_num].num_indices == 0) ||
  * (object->data.cue_sheet.tracks[track_num].indices != NULL && object->data.cue_sheet.tracks[track_num].num_indices > 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation error, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_resize_indices(FLAC__StreamMetadata *object, unsigned track_num, unsigned new_num_indices);
 
 /** Insert an index point in a CUESHEET track at the given index.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index of the track to modify.  NOTE: this is not
  *                     necessarily the same as the track's \a number field.
  * \param index_num    The index into the track's index array at which to
  *                     insert the index point.  NOTE: this is not necessarily
  *                     the same as the index point's \a number field.  The
  *                     indices at and after \a index_num move right one
  *                     position.  To append an index point to the end, set
  *                     \a index_num to
  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
  * \param index        The index point to insert.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 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);
 
 /** Insert a blank index point in a CUESHEET track at the given index.
  *
  *  A blank index point is one in which all field values are zero.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index of the track to modify.  NOTE: this is not
  *                     necessarily the same as the track's \a number field.
  * \param index_num    The index into the track's index array at which to
  *                     insert the index point.  NOTE: this is not necessarily
  *                     the same as the index point's \a number field.  The
  *                     indices at and after \a index_num move right one
  *                     position.  To append an index point to the end, set
  *                     \a index_num to
  *                     \c object->data.cue_sheet.tracks[track_num].num_indices .
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
  *    \code object->data.cue_sheet.tracks[track_num].num_indices >= index_num \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_blank_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
 
 /** Delete an index point in a CUESHEET track at the given index.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index into the track array of the track to
  *                     modify.  NOTE: this is not necessarily the same
  *                     as the track's \a number field.
  * \param index_num    The index into the track's index array of the index
  *                     to delete.  NOTE: this is not necessarily the same
  *                     as the index's \a number field.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
  *    \code object->data.cue_sheet.tracks[track_num].num_indices > index_num \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_delete_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num);
 
 /** Resize the track array.
  *
  *  If the size shrinks, elements will truncated; if it grows, new blank
  *  tracks will be added to the end.
  *
  * \param object            A pointer to an existing CUESHEET object.
  * \param new_num_tracks    The desired length of the array; may be \c 0.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code (object->data.cue_sheet.tracks == NULL && object->data.cue_sheet.num_tracks == 0) ||
  * (object->data.cue_sheet.tracks != NULL && object->data.cue_sheet.num_tracks > 0) \endcode
  * \retval FLAC__bool
  *    \c false if memory allocation error, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_resize_tracks(FLAC__StreamMetadata *object, unsigned new_num_tracks);
 
 /** Sets a track in a CUESHEET block.
  *
  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
  *  takes ownership of the \a track pointer.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    Index into track array to set.  NOTE: this is not
  *                     necessarily the same as the track's \a number field.
  * \param track        The track to set the track to.  You may safely pass in
  *                     a const pointer if \a copy is \c true.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code track_num < object->data.cue_sheet.num_tracks \endcode
  *    \code (track->indices != NULL && track->num_indices > 0) ||
  * (track->indices == NULL && track->num_indices == 0)
  * \retval FLAC__bool
  *    \c false if \a copy is \c true and malloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_set_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
 
 /** Insert a track in a CUESHEET block at the given index.
  *
  *  If \a copy is \c true, a copy of the track is stored; otherwise, the object
  *  takes ownership of the \a track pointer.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index at which to insert the track.  NOTE: this
  *                     is not necessarily the same as the track's \a number
  *                     field.  The tracks at and after \a track_num move right
  *                     one position.  To append a track to the end, set
  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
  * \param track        The track to insert.  You may safely pass in a const
  *                     pointer if \a copy is \c true.
  * \param copy         See above.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
  * \retval FLAC__bool
  *    \c false if \a copy is \c true and malloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy);
 
 /** Insert a blank track in a CUESHEET block at the given index.
  *
  *  A blank track is one in which all field values are zero.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index at which to insert the track.  NOTE: this
  *                     is not necessarily the same as the track's \a number
  *                     field.  The tracks at and after \a track_num move right
  *                     one position.  To append a track to the end, set
  *                     \a track_num to \c object->data.cue_sheet.num_tracks .
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks >= track_num \endcode
  * \retval FLAC__bool
  *    \c false if \a copy is \c true and malloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_blank_track(FLAC__StreamMetadata *object, unsigned track_num);
 
 /** Delete a track in a CUESHEET block at the given index.
  *
  * \param object       A pointer to an existing CUESHEET object.
  * \param track_num    The index into the track array of the track to
  *                     delete.  NOTE: this is not necessarily the same
  *                     as the track's \a number field.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  *    \code object->data.cue_sheet.num_tracks > track_num \endcode
  * \retval FLAC__bool
  *    \c false if realloc() fails, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_delete_track(FLAC__StreamMetadata *object, unsigned track_num);
 
 /** Check a cue sheet to see if it conforms to the FLAC specification.
  *  See the format specification for limits on the contents of the
  *  cue sheet.
  *
  * \param object     A pointer to an existing CUESHEET object.
  * \param check_cd_da_subset  If \c true, check CUESHEET against more
  *                   stringent requirements for a CD-DA (audio) disc.
  * \param violation  Address of a pointer to a string.  If there is a
  *                   violation, a pointer to a string explanation of the
  *                   violation will be returned here. \a violation may be
  *                   \c NULL if you don't need the returned string.  Do not
  *                   free the returned string; it will always point to static
  *                   data.
  * \assert
  *    \code object != NULL \endcode
  *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
  * \retval FLAC__bool
  *    \c false if cue sheet is illegal, else \c true.
  */
 FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_is_legal(const FLAC__StreamMetadata *object, FLAC__bool check_cd_da_subset, const char **violation);
 
 /* \} */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif