comparison osx/include/FLAC/metadata.h @ 87:dde06ec3df43

Add OS/X 64-bit builds

+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2001,2002,2003,2004,2005,2006,2007  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 <sys/types.h> /* for off_t */
+#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 native FLAC files.
+ *  Note that currently only the Chain interface (level 2) supports Ogg
+ *  FLAC files, and it is read-only i.e. no writing back changed
+ *  metadata to file.
+ *
+ *  There are three metadata interfaces of increasing complexity:
+ *
+ *  Level 0:
+ *  Read-only access to the STREAMINFO, VORBIS_COMMENT, CUESHEET, and
+ *  PICTURE 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 situations where 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, VORBIS_COMMENT, CUESHEET, and PICTURE blocks, requiring
+ *  only a filename.
+ *
+ *  They try to skip any ID3v2 tag at the head of the file.
+ *
+ * \{
+ */
+
+/** Read the STREAMINFO metadata block of the given FLAC file.  This function
+ *  will try to 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 try to 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 tags != 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 metadata 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);
+
+/** Read the CUESHEET metadata block of the given FLAC file.  This
+ *  function will try to skip any ID3v2 tag at the head of the file.
+ *
+ * \param filename    The path to the FLAC file to read.
+ * \param cuesheet    The address where the returned pointer will be
+ *                    stored.  The \a cuesheet object must be deleted by
+ *                    the caller using FLAC__metadata_object_delete().
+ * \assert
+ *    \code filename != NULL \endcode
+ *    \code cuesheet != NULL \endcode
+ * \retval FLAC__bool
+ *    \c true if a valid CUESHEET block was read from \a filename,
+ *    and \a *cuesheet will be set to the address of the metadata
+ *    structure.  Returns \c false if there was a memory allocation
+ *    error, a file decoder error, or the file contained no CUESHEET
+ *    block, and \a *cuesheet will be set to \c NULL.
+ */
+FLAC_API FLAC__bool FLAC__metadata_get_cuesheet(const char *filename, FLAC__StreamMetadata **cuesheet);
+
+/** Read a PICTURE metadata block of the given FLAC file.  This
+ *  function will try to skip any ID3v2 tag at the head of the file.
+ *  Since there can be more than one PICTURE block in a file, this
+ *  function takes a number of parameters that act as constraints to
+ *  the search.  The PICTURE block with the largest area matching all
+ *  the constraints will be returned, or \a *picture will be set to
+ *  \c NULL if there was no such block.
+ *
+ * \param filename    The path to the FLAC file to read.
+ * \param picture     The address where the returned pointer will be
+ *                    stored.  The \a picture object must be deleted by
+ *                    the caller using FLAC__metadata_object_delete().
+ * \param type        The desired picture type.  Use \c -1 to mean
+ *                    "any type".
+ * \param mime_type   The desired MIME type, e.g. "image/jpeg".  The
+ *                    string will be matched exactly.  Use \c NULL to
+ *                    mean "any MIME type".
+ * \param description The desired description.  The string will be
+ *                    matched exactly.  Use \c NULL to mean "any
+ *                    description".
+ * \param max_width   The maximum width in pixels desired.  Use
+ *                    \c (unsigned)(-1) to mean "any width".
+ * \param max_height  The maximum height in pixels desired.  Use
+ *                    \c (unsigned)(-1) to mean "any height".
+ * \param max_depth   The maximum color depth in bits-per-pixel desired.
+ *                    Use \c (unsigned)(-1) to mean "any depth".
+ * \param max_colors  The maximum number of colors desired.  Use
+ *                    \c (unsigned)(-1) to mean "any number of colors".
+ * \assert
+ *    \code filename != NULL \endcode
+ *    \code picture != NULL \endcode
+ * \retval FLAC__bool
+ *    \c true if a valid PICTURE block was read from \a filename,
+ *    and \a *picture will be set to the address of the metadata
+ *    structure.  Returns \c false if there was a memory allocation
+ *    error, a file decoder error, or the file contained no PICTURE
+ *    block, and \a *picture will be set to \c NULL.
+ */
+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);
+
+/* \} */
+
+
+/** \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 only read access is allowed.
+ * - Use FLAC__metadata_simple_iterator_next() and
+ *   FLAC__metadata_simple_iterator_prev() to traverse 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(void);
+
+/** 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);
+
+/** Returns a flag telling if the current metadata block is the last.
+ *
+ * \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 true if the current metadata block is the last in the file,
+ *    else \c false.
+ */
+FLAC_API FLAC__bool FLAC__metadata_simple_iterator_is_last(const FLAC__Metadata_SimpleIterator *iterator);
+
+/** Get the offset 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 off_t
+ *    The offset of the metadata block at the current iterator position.
+ *    This is the byte offset relative to the beginning of the file of
+ *    the current metadata block's header.
+ */
+FLAC_API off_t FLAC__metadata_simple_iterator_get_block_offset(const 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 length 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 unsigned
+ *    The length of the metadata block at the current iterator position.
+ *    The is same length as that in the
+ *    <a href="http://flac.sourceforge.net/format.html#metadata_block_header">metadata block header</a>,
+ *    i.e. the length of the metadata body that follows the header.
+ */
+FLAC_API unsigned FLAC__metadata_simple_iterator_get_block_length(const FLAC__Metadata_SimpleIterator *iterator);
+
+/** Get the application ID of the \c APPLICATION 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.
+ * \param id        A pointer to a buffer of at least \c 4 bytes where
+ *                  the ID will be stored.
+ * \assert
+ *    \code iterator != NULL \endcode
+ *    \code id != NULL \endcode
+ *    \a iterator has been successfully initialized with
+ *    FLAC__metadata_simple_iterator_init()
+ * \retval FLAC__bool
+ *    \c true if the ID was successfully read, else \c false, in which
+ *    case you should check FLAC__metadata_simple_iterator_status() to
+ *    find out why.  If the status is
+ *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT, then the
+ *    current metadata block is not an \c APPLICATION block.  Otherwise
+ *    if the status is
+ *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_READ_ERROR or
+ *    \c FLAC__METADATA_SIMPLE_ITERATOR_STATUS_SEEK_ERROR, an I/O error
+ *    occurred and the iterator can no longer be used.
+ */
+FLAC_API FLAC__bool FLAC__metadata_simple_iterator_get_application_id(FLAC__Metadata_SimpleIterator *iterator, FLAC__byte *id);
+
+/** 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, or \c NULL if there was a memory
+ *    allocation error.
+ */
+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.
+ *
+ * Currently Ogg FLAC is supported for read only, via
+ * FLAC__metadata_chain_read_ogg() but a subsequent
+ * FLAC__metadata_chain_write() will fail.
+ *
+ * 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() or FLAC__metadata_chain_read_ogg() 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()/FLAC__metadata_chain_read_ogg()
+ * 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()/FLAC__metadata_chain_read_ogg_with_callbacks(),
+	 *   or 
+	 *   FLAC__metadata_chain_write_with_callbacks()/FLAC__metadata_chain_write_with_callbacks_and_tempfile()
+	 *   was called on a chain read by
+	 *   FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
+	 *   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(void);
+
+/** 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 an Ogg FLAC file into the chain.
+ *
+ * \note Ogg FLAC metadata data writing is not supported yet and
+ * FLAC__metadata_chain_write() will fail.
+ *
+ * \param chain    A pointer to an existing chain.
+ * \param filename The path to the Ogg 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_ogg(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);
+
+/** Read all metadata from an Ogg 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).
+ *
+ * \note Ogg FLAC metadata data writing is not supported yet and
+ * FLAC__metadata_chain_write() will fail.
+ *
+ * \param chain    A pointer to an existing chain.
+ * \param handle   The I/O handle of the Ogg 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_ogg_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()/FLAC__metadata_chain_read_ogg(), not
+ *  FLAC__metadata_chain_read_with_callbacks()/FLAC__metadata_chain_read_ogg_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()/FLAC__metadata_chain_read_ogg_with_callbacks(),
+ *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
+ *  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()/FLAC__metadata_chain_read_ogg_with_callbacks(),
+ *  not FLAC__metadata_chain_read()/FLAC__metadata_chain_read_ogg().
+ *  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(void);
+
+/** 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.  The existing data will be freed if this
+ *  function is successful, otherwise the original data will remain if \a copy
+ *  is \c true and malloc() fails.
+ *
+ * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
+ *
+ * \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
+ *    \code total_samples > 0 \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);
+
+/** 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 samples The number of samples apart to space the placeholder
+ *                points.  The first point will be at sample \c 0, the
+ *                second at sample \a samples, then 2*\a samples, and
+ *                so on.  As long as \a samples and \a total_samples
+ *                are greater than \c 0, there will always be at least
+ *                one seekpoint at sample \c 0.
+ * \param total_samples  The total number of samples to be encoded;
+ *                       the seekpoints will be spaced
+ *                       \a samples samples apart.
+ * \assert
+ *    \code object != NULL \endcode
+ *    \code object->type == FLAC__METADATA_TYPE_SEEKTABLE \endcode
+ *    \code samples > 0 \endcode
+ *    \code total_samples > 0 \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_by_samples(FLAC__StreamMetadata *object, unsigned samples, 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(void);
+
+/** 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);
+
+/** Calculate and return the CDDB/freedb ID for a cue sheet.  The function
+ *  assumes the cue sheet corresponds to a CD; the result is undefined
+ *  if the cuesheet's is_cd bit is not set.
+ *
+ * \param object     A pointer to an existing CUESHEET object.
+ * \assert
+ *    \code object != NULL \endcode
+ *    \code object->type == FLAC__METADATA_TYPE_CUESHEET \endcode
+ * \retval FLAC__uint32
+ *    The unsigned integer representation of the CDDB/freedb ID
+ */
+FLAC_API FLAC__uint32 FLAC__metadata_object_cuesheet_calculate_cddb_id(const FLAC__StreamMetadata *object);
+
+/** Sets the MIME type of a PICTURE block.
+ *
+ *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
+ *  takes ownership of the pointer.  The existing string will be freed if this
+ *  function is successful, otherwise the original string will remain if \a copy
+ *  is \c true and malloc() fails.
+ *
+ * \note It is safe to pass a const pointer to \a mime_type if \a copy is \c true.
+ *
+ * \param object      A pointer to an existing PICTURE object.
+ * \param mime_type   A pointer to the MIME type string.  The string must be
+ *                    ASCII characters 0x20-0x7e, NUL-terminated.  No validation
+ *                    is done.
+ * \param copy        See above.
+ * \assert
+ *    \code object != NULL \endcode
+ *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
+ *    \code (mime_type != NULL) \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_picture_set_mime_type(FLAC__StreamMetadata *object, char *mime_type, FLAC__bool copy);
+
+/** Sets the description of a PICTURE block.
+ *
+ *  If \a copy is \c true, a copy of the string is stored; otherwise, the object
+ *  takes ownership of the pointer.  The existing string will be freed if this
+ *  function is successful, otherwise the original string will remain if \a copy
+ *  is \c true and malloc() fails.
+ *
+ * \note It is safe to pass a const pointer to \a description if \a copy is \c true.
+ *
+ * \param object      A pointer to an existing PICTURE object.
+ * \param description A pointer to the description string.  The string must be
+ *                    valid UTF-8, NUL-terminated.  No validation is done.
+ * \param copy        See above.
+ * \assert
+ *    \code object != NULL \endcode
+ *    \code object->type == FLAC__METADATA_TYPE_PICTURE \endcode
+ *    \code (description != NULL) \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_picture_set_description(FLAC__StreamMetadata *object, FLAC__byte *description, FLAC__bool copy);
+
+/** Sets the picture data of a PICTURE block.
+ *
+ *  If \a copy is \c true, a copy of the data is stored; otherwise, the object
+ *  takes ownership of the pointer.  Also sets the \a data_length field of the
+ *  metadata object to what is passed in as the \a length parameter.  The
+ *  existing data will be freed if this function is successful, otherwise the
+ *  original data and data_length will remain if \a copy is \c true and
+ *  malloc() fails.
+ *
+ * \note It is safe to pass a const pointer to \a data if \a copy is \c true.
+ *
+ * \param object  A pointer to an existing PICTURE 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_PICTURE \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_picture_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, FLAC__uint32 length, FLAC__bool copy);
+
+/** Check a PICTURE block to see if it conforms to the FLAC specification.
+ *  See the format specification for limits on the contents of the
+ *  PICTURE block.
+ *
+ * \param object     A pointer to existing PICTURE block to be checked.
+ * \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_PICTURE \endcode
+ * \retval FLAC__bool
+ *    \c false if PICTURE block is illegal, else \c true.
+ */
+FLAC_API FLAC__bool FLAC__metadata_object_picture_is_legal(const FLAC__StreamMetadata *object, const char **violation);
+
+/* \} */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif