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diff --git a/include/FLAC/metadata.h b/include/FLAC/metadata.h new file mode 100644 index 0000000..4747a5f --- /dev/null +++ b/include/FLAC/metadata.h @@ -0,0 +1,2234 @@ +/* libFLAC - Free Lossless Audio Codec library + * Copyright (C) 2001-2009 Josh Coalson + * Copyright (C) 2011-2023 Xiph.Org Foundation + * + * 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 accommodated 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. + * + * On Windows, filename must be a UTF-8 encoded filename, which libFLAC + * internally translates to an appropriate representation to use with + * _wfopen. On all other systems, filename is passed to fopen without + * any translation. + * + * 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 (uint32_t)(-1) to mean "any width". + * \param max_height The maximum height in pixels desired. Use + * \c (uint32_t)(-1) to mean "any height". + * \param max_depth The maximum color depth in bits-per-pixel desired. + * Use \c (uint32_t)(-1) to mean "any depth". + * \param max_colors The maximum number of colors desired. Use + * \c (uint32_t)(-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, uint32_t max_width, uint32_t max_height, uint32_t max_depth, uint32_t 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. + * + * On Windows, filename must be a UTF-8 encoded filename, which libFLAC + * internally translates to an appropriate representation to use with + * _wfopen. On all other systems, filename is passed to fopen without + * any translation. + * + * \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 uint32_t + * The length of the metadata block at the current iterator position. + * The is same length as that in the + * <a href="http://xiph.org/flhttps://xiph.org/flac/format.html#metadata_block_header">metadata block header</a>, + * i.e. the length of the metadata body that follows the header. + */ +FLAC_API uint32_t 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 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. + * + * On Windows, filename must be a UTF-8 encoded filename, which libFLAC + * internally translates to an appropriate representation to use with + * _wfopen. On all other systems, filename is passed to fopen without + * any translation. + * + * \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. + * + * On Windows, filename must be a UTF-8 encoded filename, which libFLAC + * internally translates to an appropriate representation to use with + * _wfopen. On all other systems, filename is passed to fopen without + * any translation. + * + * \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, uint32_t 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. If this function returns false, the + * object is left untouched. + * + * \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, uint32_t 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, uint32_t 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, uint32_t 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, uint32_t 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, uint32_t 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[], uint32_t 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, uint32_t 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, uint32_t 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. If this function returns false, the + * object is left untouched. + * + * \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, uint32_t 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, uint32_t 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, uint32_t 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 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, uint32_t 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, uint32_t 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, uint32_t 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. If this function returns false, the + * track object is left untouched. + * + * \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, uint32_t track_num, uint32_t 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, uint32_t track_num, uint32_t 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, uint32_t track_num, uint32_t 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, uint32_t track_num, uint32_t 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. If this function returns false, the + * object is left untouched. + * + * \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, uint32_t 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) \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_set_track(FLAC__StreamMetadata *object, uint32_t 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, uint32_t 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, uint32_t 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, uint32_t 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); + + +/** Get the raw (binary) representation of a FLAC__StreamMetadata objeect. + * After use, free() the returned buffer. The length of the buffer is + * the length of the input metadata object plus 4 bytes for the header. + * + * \param object A pointer to metadata block to be converted. + * \assert + * \code object != NULL \endcode + * \retval FLAC__byte* + * \c NULL if there was an error, else a pointer to a buffer holding + * the requested data. + */ +FLAC_API FLAC__byte * FLAC__metadata_object_get_raw(const FLAC__StreamMetadata *object); + + +/** Turn a raw (binary) representation into a FLAC__StreamMetadata objeect. + * The returned object must be deleted with FLAC__metadata_object_delete() + * after use. + * + * \param buffer A pointer to a buffer containing a binary representation + * to be converted to a FLAC__StreamMetadata object + * \param length The length of the supplied buffer + * \retval FLAC__StreamMetadata* + * \c NULL if there was an error, else a pointer to a FLAC__StreamMetadata + * holding the requested data. + */ + +FLAC_API FLAC__StreamMetadata * FLAC__metadata_object_set_raw(FLAC__byte *buffer, FLAC__uint32 length); +/* \} */ + +#ifdef __cplusplus +} +#endif + +#endif |