/* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2000-2009 Josh Coalson
* Copyright (C) 2011-2025 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__FORMAT_H
#define FLAC__FORMAT_H
#include "export.h"
#include "ordinals.h"
#ifdef __cplusplus
extern "C" {
#endif
/** \file include/FLAC/format.h
*
* \brief
* This module contains structure definitions for the representation
* of FLAC format components in memory. These are the basic
* structures used by the rest of the interfaces.
*
* See the detailed documentation in the
* \link flac_format format \endlink module.
*/
/** \defgroup flac_format FLAC/format.h: format components
* \ingroup flac
*
* \brief
* This module contains structure definitions for the representation
* of FLAC format components in memory. These are the basic
* structures used by the rest of the interfaces.
*
* First, you should be familiar with the
* <A HREF="https://xiph.org/flac/format.html">FLAC format</A>. Many of the values here
* follow directly from the specification. As a user of libFLAC, the
* interesting parts really are the structures that describe the frame
* header and metadata blocks.
*
* The format structures here are very primitive, designed to store
* information in an efficient way. Reading information from the
* structures is easy but creating or modifying them directly is
* more complex. For the most part, as a user of a library, editing
* is not necessary; however, for metadata blocks it is, so there are
* convenience functions provided in the \link flac_metadata metadata
* module \endlink to simplify the manipulation of metadata blocks.
*
* \note
* It's not the best convention, but symbols ending in _LEN are in bits
* and _LENGTH are in bytes. _LENGTH symbols are \#defines instead of
* global variables because they are usually used when declaring byte
* arrays and some compilers require compile-time knowledge of array
* sizes when declared on the stack.
*
* \{
*/
/*
Most of the values described in this file are defined by the FLAC
format specification. There is nothing to tune here.
*/
/** The largest legal metadata type code. */
#define FLAC__MAX_METADATA_TYPE_CODE (126u)
/** The minimum block size, in samples, permitted by the format. */
#define FLAC__MIN_BLOCK_SIZE (16u)
/** The maximum block size, in samples, permitted by the format. */
#define FLAC__MAX_BLOCK_SIZE (65535u)
/** The maximum block size, in samples, permitted by the FLAC subset for
* sample rates up to 48kHz. */
#define FLAC__SUBSET_MAX_BLOCK_SIZE_48000HZ (4608u)
/** The maximum number of channels permitted by the format. */
#define FLAC__MAX_CHANNELS (8u)
/** The minimum sample resolution permitted by the format. */
#define FLAC__MIN_BITS_PER_SAMPLE (4u)
/** The maximum sample resolution permitted by the format. */
#define FLAC__MAX_BITS_PER_SAMPLE (32u)
/** The maximum sample resolution permitted by libFLAC.
*
* FLAC__MAX_BITS_PER_SAMPLE is the limit of the FLAC format. However,
* the reference encoder/decoder used to be limited to 24 bits. This
* value was used to signal that limit.
*/
#define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (32u)
/** The maximum sample rate permitted by the format. The value is
* ((2 ^ 20) - 1)
*/
#define FLAC__MAX_SAMPLE_RATE (1048575u)
/** The maximum LPC order permitted by the format. */
#define FLAC__MAX_LPC_ORDER (32u)
/** The maximum LPC order permitted by the FLAC subset for sample rates
* up to 48kHz. */
#define FLAC__SUBSET_MAX_LPC_ORDER_48000HZ (12u)
/** The minimum quantized linear predictor coefficient precision
* permitted by the format.
*/
#define FLAC__MIN_QLP_COEFF_PRECISION (5u)
/** The maximum quantized linear predictor coefficient precision
* permitted by the format.
*/
#define FLAC__MAX_QLP_COEFF_PRECISION (15u)
/** The maximum order of the fixed predictors permitted by the format. */
#define FLAC__MAX_FIXED_ORDER (4u)
/** The maximum Rice partition order permitted by the format. */
#define FLAC__MAX_RICE_PARTITION_ORDER (15u)
/** The maximum Rice partition order permitted by the FLAC Subset. */
#define FLAC__SUBSET_MAX_RICE_PARTITION_ORDER (8u)
/** The version string of the release, stamped onto the libraries and binaries.
*
* \note
* This does not correspond to the shared library version number, which
* is used to determine binary compatibility.
*/
extern FLAC_API const char *FLAC__VERSION_STRING;
/** The vendor string inserted by the encoder into the VORBIS_COMMENT block.
* This is a NUL-terminated ASCII string; when inserted into the
* VORBIS_COMMENT the trailing null is stripped.
*/
extern FLAC_API const char *FLAC__VENDOR_STRING;
/** The byte string representation of the beginning of a FLAC stream. */
extern FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4]; /* = "fLaC" */
/** The 32-bit integer big-endian representation of the beginning of
* a FLAC stream.
*/
extern FLAC_API const uint32_t FLAC__STREAM_SYNC; /* = 0x664C6143 */
/** The length of the FLAC signature in bits. */
extern FLAC_API const uint32_t FLAC__STREAM_SYNC_LEN; /* = 32 bits */
/** The length of the FLAC signature in bytes. */
#define FLAC__STREAM_SYNC_LENGTH (4u)
/*****************************************************************************
*
* Subframe structures
*
*****************************************************************************/
/*****************************************************************************/
/** An enumeration of the available entropy coding methods. */
typedef enum {
FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0,
/**< Residual is coded by partitioning into contexts, each with it's own
* 4-bit Rice parameter. */
FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2 = 1
/**< Residual is coded by partitioning into contexts, each with it's own
* 5-bit Rice parameter. */
} FLAC__EntropyCodingMethodType;
/** Maps a FLAC__EntropyCodingMethodType to a C string.
*
* Using a FLAC__EntropyCodingMethodType as the index to this array will
* give the string equivalent. The contents should not be modified.
*/
extern FLAC_API const char * const FLAC__EntropyCodingMethodTypeString[];
/** Contents of a Rice partitioned residual
*/
typedef struct {
uint32_t *parameters;
/**< The Rice parameters for each context. */
uint32_t *raw_bits;
/**< Widths for escape-coded partitions. Will be non-zero for escaped
* partitions and zero for unescaped partitions.
*/
uint32_t capacity_by_order;
/**< The capacity of the \a parameters and \a raw_bits arrays
* specified as an order, i.e. the number of array elements
* allocated is 2 ^ \a capacity_by_order.
*/
} FLAC__EntropyCodingMethod_PartitionedRiceContents;
/** Header for a Rice partitioned residual. (c.f. <A HREF="https://xiph.org/flac/format.html#partitioned_rice">format specification</A>)
*/
typedef struct {
uint32_t order;
/**< The partition order, i.e. # of contexts = 2 ^ \a order. */
const FLAC__EntropyCodingMethod_PartitionedRiceContents *contents;
/**< The context's Rice parameters and/or raw bits. */
} FLAC__EntropyCodingMethod_PartitionedRice;
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN; /**< == 5 (bits) */
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /**< == 5 (bits) */
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;
/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_ESCAPE_PARAMETER;
/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE2_PARAMETER_LEN)-1 */
/** Header for the entropy coding method. (c.f. <A HREF="https://xiph.org/flac/format.html#residual">format specification</A>)
*/
typedef struct {
FLAC__EntropyCodingMethodType type;
union {
FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
} data;
} FLAC__EntropyCodingMethod;
extern FLAC_API const uint32_t FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /**< == 2 (bits) */
/*****************************************************************************/
/** An enumeration of the available subframe types. */
typedef enum {
FLAC__SUBFRAME_TYPE_CONSTANT = 0, /**< constant signal */
FLAC__SUBFRAME_TYPE_VERBATIM = 1, /**< uncompressed signal */
FLAC__SUBFRAME_TYPE_FIXED = 2, /**< fixed polynomial prediction */
FLAC__SUBFRAME_TYPE_LPC = 3 /**< linear prediction */
} FLAC__SubframeType;
/** Maps a FLAC__SubframeType to a C string.
*
* Using a FLAC__SubframeType as the index to this array will
* give the string equivalent. The contents should not be modified.
*/
extern FLAC_API const char * const FLAC__SubframeTypeString[];
/** CONSTANT subframe. (c.f. <A HREF="https://xiph.org/flac/format.html#subframe_constant">format specification</A>)
*/
typedef struct {
FLAC__int64 value; /**< The constant signal value. */
} FLAC__Subframe_Constant;
/** An enumeration of the possible verbatim subframe data types. */
typedef enum {
FLAC__VERBATIM_SUBFRAME_DATA_TYPE_INT32, /**< verbatim subframe has 32-bit int */
FLAC__VERBATIM_SUBFRAME_DATA_TYPE_INT64 /**< verbatim subframe has 64-bit int */
} FLAC__VerbatimSubframeDataType;
/** VERBATIM subframe. (c.f. <A HREF="https://xiph.org/flac/format.html#subframe_verbatim">format specification</A>)
*/
typedef struct {
union {
const FLAC__int32 *int32; /**< A FLAC__int32 pointer to verbatim signal. */
const FLAC__int64 *int64; /**< A FLAC__int64 pointer to verbatim signal. */
} data;
FLAC__VerbatimSubframeDataType data_type;
} FLAC__Subframe_Verbatim;
/** FIXED subframe. (c.f. <A HREF="https://xiph.org/flac/format.html#subframe_fixed">format specification</A>)
*/
typedef struct {
FLAC__EntropyCodingMethod entropy_coding_method;
/**< The residual coding method. */
uint32_t order;
/**< The polynomial order. */
FLAC__int64 warmup[FLAC__MAX_FIXED_ORDER];
/**< Warmup samples to prime the predictor, length == order. */
const FLAC__int32 *residual;
/**< The residual signal, length == (blocksize minus order) samples. */
} FLAC__Subframe_Fixed;
/** LPC subframe. (c.f. <A HREF="https://xiph.org/flac/format.html#subframe_lpc">format specification</A>)
*/
typedef struct {
FLAC__EntropyCodingMethod entropy_coding_method;
/**< The residual coding method. */
uint32_t order;
/**< The FIR order. */
uint32_t qlp_coeff_precision;
/**< Quantized FIR filter coefficient precision in bits. */
int quantization_level;
/**< The qlp coeff shift needed. */
FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
/**< FIR filter coefficients. */
FLAC__int64 warmup[FLAC__MAX_LPC_ORDER];
/**< Warmup samples to prime the predictor, length == order. */
const FLAC__int32 *residual;
/**< The residual signal, length == (blocksize minus order) samples. */
} FLAC__Subframe_LPC;
extern FLAC_API const uint32_t FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /**< == 5 (bits) */
/** FLAC subframe structure. (c.f. <A HREF="https://xiph.org/flac/format.html#subframe">format specification</A>)
*/
typedef struct {
FLAC__SubframeType type;
union {
FLAC__Subframe_Constant constant;
FLAC__Subframe_Fixed fixed;
FLAC__Subframe_LPC lpc;
FLAC__Subframe_Verbatim verbatim;
} data;
uint32_t wasted_bits;
} FLAC__Subframe;
/** == 1 (bit)
*
* This used to be a zero-padding bit (hence the name
* FLAC__SUBFRAME_ZERO_PAD_LEN) but is now a reserved bit. It still has a
* mandatory value of \c 0 but in the future may take on the value \c 0 or \c 1
* to mean something else.
*/
extern FLAC_API const uint32_t FLAC__SUBFRAME_ZERO_PAD_LEN;
extern FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_LEN; /**< == 6 (bits) */
extern FLAC_API const uint32_t FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /**< = 0x00 */
extern FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /**< = 0x02 */
extern FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /**< = 0x10 */
extern FLAC_API const uint32_t FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK; /**< = 0x40 */
/*****************************************************************************/
/*****************************************************************************
*
* Frame structures
*
*****************************************************************************/
/** An enumeration of the available channel assignments. */
typedef enum {
FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT = 0, /**< independent channels */
FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE = 1, /**< left+side stereo */
FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE = 2, /**< right+side stereo */
FLAC__CHANNEL_ASSIGNMENT_MID_SIDE = 3 /**< mid+side stereo */
} FLAC__ChannelAssignment;
/** Maps a FLAC__ChannelAssignment to a C string.
*
* Using a FLAC__ChannelAssignment as the index to this array will
* give the string equivalent. The contents should not be modified.
*/
extern FLAC_API const char * const FLAC__ChannelAssignmentString[];
/** An enumeration of the possible frame numbering methods. */
typedef enum {
FLAC__FRAME_NUMBER_TYPE_FRAME_NUMBER, /**< number contains the frame number */
FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER /**< number contains the sample number of first sample in frame */
} FLAC__FrameNumberType;
/** Maps a FLAC__FrameNumberType to a C string.
*
* Using a FLAC__FrameNumberType as the index to this array will
* give the string equivalent. The contents should not be modified.
*/
extern FLAC_API const char * const FLAC__FrameNumberTypeString[];
/** FLAC frame header structure. (c.f. <A HREF="https://xiph.org/flac/format.html#frame_header">format specification</A>)
*/
typedef struct {
uint32_t blocksize;
/**< The number of samples per subframe. */
uint32_t sample_rate;
/**< The sample rate in Hz. */
uint32_t channels;
/**< The number of channels (== number of subframes). */
FLAC__ChannelAssignment channel_assignment;
/**< The channel assignment for the frame. */
uint32_t bits_per_sample;
/**< The sample resolution. */
FLAC__FrameNumberType number_type;
/**< The numbering scheme used for the frame. As a convenience, the
* decoder will always convert a frame number to a sample number because
* the rules are complex. */
union {
FLAC__uint32 frame_number;
FLAC__uint64 sample_number;
} number;
/**< The frame number or sample number of first sample in frame;
* use the \a number_type value to determine which to use. */
FLAC__uint8 crc;
/**< CRC-8 (polynomial = x^8 + x^2 + x^1 + x^0, initialized with 0)
* of the raw frame header bytes, meaning everything before the CRC byte
* including the sync code.
*/
} FLAC__FrameHeader;
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_SYNC; /**< == 0x3ffe; the frame header sync code */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_SYNC_LEN; /**< == 14 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_RESERVED_LEN; /**< == 1 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_BLOCKING_STRATEGY_LEN; /**< == 1 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /**< == 4 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /**< == 3 (bits) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_ZERO_PAD_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__FRAME_HEADER_CRC_LEN; /**< == 8 (bits) */
/** FLAC frame footer structure. (c.f. <A HREF="https://xiph.org/flac/format.html#frame_footer">format specification</A>)
*/
typedef struct {
FLAC__uint16 crc;
/**< CRC-16 (polynomial = x^16 + x^15 + x^2 + x^0, initialized with
* 0) of the bytes before the crc, back to and including the frame header
* sync code.
*/
} FLAC__FrameFooter;
extern FLAC_API const uint32_t FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
/** FLAC frame structure. (c.f. <A HREF="https://xiph.org/flac/format.html#frame">format specification</A>)
*/
typedef struct {
FLAC__FrameHeader header;
FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
FLAC__FrameFooter footer;
} FLAC__Frame;
/*****************************************************************************/
/*****************************************************************************
*
* Meta-data structures
*
*****************************************************************************/
/** An enumeration of the available metadata block types. */
typedef enum {
FLAC__METADATA_TYPE_STREAMINFO = 0,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_streaminfo">STREAMINFO</A> block */
FLAC__METADATA_TYPE_PADDING = 1,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_padding">PADDING</A> block */
FLAC__METADATA_TYPE_APPLICATION = 2,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_application">APPLICATION</A> block */
FLAC__METADATA_TYPE_SEEKTABLE = 3,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_seektable">SEEKTABLE</A> block */
FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_vorbis_comment">VORBISCOMMENT</A> block (a.k.a. FLAC tags) */
FLAC__METADATA_TYPE_CUESHEET = 5,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_cuesheet">CUESHEET</A> block */
FLAC__METADATA_TYPE_PICTURE = 6,
/**< <A HREF="https://xiph.org/flac/format.html#metadata_block_picture">PICTURE</A> block */
FLAC__METADATA_TYPE_UNDEFINED = 7,
/**< marker to denote beginning of undefined type range; this number will increase as new metadata types are added */
FLAC__MAX_METADATA_TYPE = FLAC__MAX_METADATA_TYPE_CODE,
/**< No type will ever be greater than this. There is not enough room in the protocol block. */
} FLAC__MetadataType;
/** Maps a FLAC__MetadataType to a C string.
*
* Using a FLAC__MetadataType as the index to this array will
* give the string equivalent. The contents should not be modified.
*/
extern FLAC_API const char * const FLAC__MetadataTypeString[];
/** FLAC STREAMINFO structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_streaminfo">format specification</A>)
*/
typedef struct {
uint32_t min_blocksize, max_blocksize;
uint32_t min_framesize, max_framesize;
uint32_t sample_rate;
uint32_t channels;
uint32_t bits_per_sample;
FLAC__uint64 total_samples;
FLAC__byte md5sum[16];
} FLAC__StreamMetadata_StreamInfo;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /**< == 128 (bits) */
/** The total stream length of the STREAMINFO block in bytes. */
#define FLAC__STREAM_METADATA_STREAMINFO_LENGTH (34u)
/** FLAC PADDING structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_padding">format specification</A>)
*/
typedef struct {
int dummy;
/**< Conceptually this is an empty struct since we don't store the
* padding bytes. Empty structs are not allowed by some C compilers,
* hence the dummy.
*/
} FLAC__StreamMetadata_Padding;
/** FLAC APPLICATION structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_application">format specification</A>)
*/
typedef struct {
FLAC__byte id[4];
FLAC__byte *data;
} FLAC__StreamMetadata_Application;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
/** SeekPoint structure used in SEEKTABLE blocks. (c.f. <A HREF="https://xiph.org/flac/format.html#seekpoint">format specification</A>)
*/
typedef struct {
FLAC__uint64 sample_number;
/**< The sample number of the target frame. */
FLAC__uint64 stream_offset;
/**< The offset, in bytes, of the target frame with respect to
* beginning of the first frame. */
uint32_t frame_samples;
/**< The number of samples in the target frame. */
} FLAC__StreamMetadata_SeekPoint;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /**< == 16 (bits) */
/** The total stream length of a seek point in bytes. */
#define FLAC__STREAM_METADATA_SEEKPOINT_LENGTH (18u)
/** The value used in the \a sample_number field of
* FLAC__StreamMetadataSeekPoint used to indicate a placeholder
* point (== 0xffffffffffffffff).
*/
extern FLAC_API const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
/** FLAC SEEKTABLE structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_seektable">format specification</A>)
*
* \note From the format specification:
* - The seek points must be sorted by ascending sample number.
* - Each seek point's sample number must be the first sample of the
* target frame.
* - Each seek point's sample number must be unique within the table.
* - Existence of a SEEKTABLE block implies a correct setting of
* total_samples in the stream_info block.
* - Behavior is undefined when more than one SEEKTABLE block is
* present in a stream.
*/
typedef struct {
uint32_t num_points;
FLAC__StreamMetadata_SeekPoint *points;
} FLAC__StreamMetadata_SeekTable;
/** Vorbis comment entry structure used in VORBIS_COMMENT blocks. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_vorbis_comment">format specification</A>)
*
* For convenience, the APIs maintain a trailing NUL character at the end of
* \a entry which is not counted toward \a length, i.e.
* \code strlen(entry) == length \endcode
*/
typedef struct {
FLAC__uint32 length;
FLAC__byte *entry;
} FLAC__StreamMetadata_VorbisComment_Entry;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN; /**< == 32 (bits) */
/** FLAC VORBIS_COMMENT structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block_vorbis_comment">format specification</A>)
*/
typedef struct {
FLAC__StreamMetadata_VorbisComment_Entry vendor_string;
FLAC__uint32 num_comments;
FLAC__StreamMetadata_VorbisComment_Entry *comments;
} FLAC__StreamMetadata_VorbisComment;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
/** FLAC CUESHEET track index structure. (See the
* <A HREF="https://xiph.org/flac/format.html#cuesheet_track_index">format specification</A> for
* the full description of each field.)
*/
typedef struct {
FLAC__uint64 offset;
/**< Offset in samples, relative to the track offset, of the index
* point.
*/
FLAC__byte number;
/**< The index point number. */
} FLAC__StreamMetadata_CueSheet_Index;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN; /**< == 64 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN; /**< == 8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN; /**< == 3*8 (bits) */
/** FLAC CUESHEET track structure. (See the
* <A HREF="https://xiph.org/flac/format.html#cuesheet_track">format specification</A> for
* the full description of each field.)
*/
typedef struct {
FLAC__uint64 offset;
/**< Track offset in samples, relative to the beginning of the FLAC audio stream. */
FLAC__byte number;
/**< The track number. */
char isrc[13];
/**< Track ISRC. This is a 12-digit alphanumeric code plus a trailing \c NUL byte */
uint32_t type:1;
/**< The track type: 0 for audio, 1 for non-audio. */
uint32_t pre_emphasis:1;
/**< The pre-emphasis flag: 0 for no pre-emphasis, 1 for pre-emphasis. */
FLAC__byte num_indices;
/**< The number of track index points. */
FLAC__StreamMetadata_CueSheet_Index *indices;
/**< NULL if num_indices == 0, else pointer to array of index points. */
} FLAC__StreamMetadata_CueSheet_Track;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN; /**< == 64 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN; /**< == 8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN; /**< == 12*8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN; /**< == 6+13*8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN; /**< == 8 (bits) */
/** FLAC CUESHEET structure. (See the
* <A HREF="https://xiph.org/flac/format.html#metadata_block_cuesheet">format specification</A>
* for the full description of each field.)
*/
typedef struct {
char media_catalog_number[129];
/**< Media catalog number, in ASCII printable characters 0x20-0x7e. In
* general, the media catalog number may be 0 to 128 bytes long; any
* unused characters should be right-padded with NUL characters.
*/
FLAC__uint64 lead_in;
/**< The number of lead-in samples. */
FLAC__bool is_cd;
/**< \c true if CUESHEET corresponds to a Compact Disc, else \c false. */
uint32_t num_tracks;
/**< The number of tracks. */
FLAC__StreamMetadata_CueSheet_Track *tracks;
/**< NULL if num_tracks == 0, else pointer to array of tracks. */
} FLAC__StreamMetadata_CueSheet;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN; /**< == 128*8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN; /**< == 64 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN; /**< == 7+258*8 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN; /**< == 8 (bits) */
/** An enumeration of the PICTURE types (see FLAC__StreamMetadataPicture and id3 v2.4 APIC tag). */
typedef enum {
FLAC__STREAM_METADATA_PICTURE_TYPE_OTHER = 0, /**< Other */
FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON_STANDARD = 1, /**< 32x32 pixels 'file icon' (PNG only) */
FLAC__STREAM_METADATA_PICTURE_TYPE_FILE_ICON = 2, /**< Other file icon */
FLAC__STREAM_METADATA_PICTURE_TYPE_FRONT_COVER = 3, /**< Cover (front) */
FLAC__STREAM_METADATA_PICTURE_TYPE_BACK_COVER = 4, /**< Cover (back) */
FLAC__STREAM_METADATA_PICTURE_TYPE_LEAFLET_PAGE = 5, /**< Leaflet page */
FLAC__STREAM_METADATA_PICTURE_TYPE_MEDIA = 6, /**< Media (e.g. label side of CD) */
FLAC__STREAM_METADATA_PICTURE_TYPE_LEAD_ARTIST = 7, /**< Lead artist/lead performer/soloist */
FLAC__STREAM_METADATA_PICTURE_TYPE_ARTIST = 8, /**< Artist/performer */
FLAC__STREAM_METADATA_PICTURE_TYPE_CONDUCTOR = 9, /**< Conductor */
FLAC__STREAM_METADATA_PICTURE_TYPE_BAND = 10, /**< Band/Orchestra */
FLAC__STREAM_METADATA_PICTURE_TYPE_COMPOSER = 11, /**< Composer */
FLAC__STREAM_METADATA_PICTURE_TYPE_LYRICIST = 12, /**< Lyricist/text writer */
FLAC__STREAM_METADATA_PICTURE_TYPE_RECORDING_LOCATION = 13, /**< Recording Location */
FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_RECORDING = 14, /**< During recording */
FLAC__STREAM_METADATA_PICTURE_TYPE_DURING_PERFORMANCE = 15, /**< During performance */
FLAC__STREAM_METADATA_PICTURE_TYPE_VIDEO_SCREEN_CAPTURE = 16, /**< Movie/video screen capture */
FLAC__STREAM_METADATA_PICTURE_TYPE_FISH = 17, /**< A bright coloured fish */
FLAC__STREAM_METADATA_PICTURE_TYPE_ILLUSTRATION = 18, /**< Illustration */
FLAC__STREAM_METADATA_PICTURE_TYPE_BAND_LOGOTYPE = 19, /**< Band/artist logotype */
FLAC__STREAM_METADATA_PICTURE_TYPE_PUBLISHER_LOGOTYPE = 20, /**< Publisher/Studio logotype */
FLAC__STREAM_METADATA_PICTURE_TYPE_UNDEFINED
} FLAC__StreamMetadata_Picture_Type;
/** Maps a FLAC__StreamMetadata_Picture_Type to a C string.
*
* Using a FLAC__StreamMetadata_Picture_Type as the index to this array
* will give the string equivalent. The contents should not be
* modified.
*/
extern FLAC_API const char * const FLAC__StreamMetadata_Picture_TypeString[];
/** FLAC PICTURE structure. (See the
* <A HREF="https://xiph.org/flac/format.html#metadata_block_picture">format specification</A>
* for the full description of each field.)
*/
typedef struct {
FLAC__StreamMetadata_Picture_Type type;
/**< The kind of picture stored. */
char *mime_type;
/**< Picture data's MIME type, in ASCII printable characters
* 0x20-0x7e, NUL terminated. For best compatibility with players,
* use picture data of MIME type \c image/jpeg or \c image/png. A
* MIME type of '-->' is also allowed, in which case the picture
* data should be a complete URL. In file storage, the MIME type is
* stored as a 32-bit length followed by the ASCII string with no NUL
* terminator, but is converted to a plain C string in this structure
* for convenience.
*/
FLAC__byte *description;
/**< Picture's description in UTF-8, NUL terminated. In file storage,
* the description is stored as a 32-bit length followed by the UTF-8
* string with no NUL terminator, but is converted to a plain C string
* in this structure for convenience.
*/
FLAC__uint32 width;
/**< Picture's width in pixels. */
FLAC__uint32 height;
/**< Picture's height in pixels. */
FLAC__uint32 depth;
/**< Picture's color depth in bits-per-pixel. */
FLAC__uint32 colors;
/**< For indexed palettes (like GIF), picture's number of colors (the
* number of palette entries), or \c 0 for non-indexed (i.e. 2^depth).
*/
FLAC__uint32 data_length;
/**< Length of binary picture data in bytes. */
FLAC__byte *data;
/**< Binary picture data. */
} FLAC__StreamMetadata_Picture;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_TYPE_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_COLORS_LEN; /**< == 32 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN; /**< == 32 (bits) */
/** Structure that is used when a metadata block of unknown type is loaded.
* The contents are opaque. The structure is used only internally to
* correctly handle unknown metadata.
*/
typedef struct {
FLAC__byte *data;
} FLAC__StreamMetadata_Unknown;
/** FLAC metadata block structure. (c.f. <A HREF="https://xiph.org/flac/format.html#metadata_block">format specification</A>)
*/
typedef struct FLAC__StreamMetadata {
FLAC__MetadataType type;
/**< The type of the metadata block; used determine which member of the
* \a data union to dereference. If type >= FLAC__METADATA_TYPE_UNDEFINED
* then \a data.unknown must be used. */
FLAC__bool is_last;
/**< \c true if this metadata block is the last, else \a false */
uint32_t length;
/**< Length, in bytes, of the block data as it appears in the stream. */
union {
FLAC__StreamMetadata_StreamInfo stream_info;
FLAC__StreamMetadata_Padding padding;
FLAC__StreamMetadata_Application application;
FLAC__StreamMetadata_SeekTable seek_table;
FLAC__StreamMetadata_VorbisComment vorbis_comment;
FLAC__StreamMetadata_CueSheet cue_sheet;
FLAC__StreamMetadata_Picture picture;
FLAC__StreamMetadata_Unknown unknown;
} data;
/**< Polymorphic block data; use the \a type value to determine which
* to use. */
} FLAC__StreamMetadata;
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
extern FLAC_API const uint32_t FLAC__STREAM_METADATA_LENGTH_LEN; /**< == 24 (bits) */
/** The total stream length of a metadata block header in bytes. */
#define FLAC__STREAM_METADATA_HEADER_LENGTH (4u)
/*****************************************************************************/
/*****************************************************************************
*
* Utility functions
*
*****************************************************************************/
/** Tests that a sample rate is valid for FLAC.
*
* \param sample_rate The sample rate to test for compliance.
* \retval FLAC__bool
* \c true if the given sample rate conforms to the specification, else
* \c false.
*/
FLAC_API FLAC__bool FLAC__format_sample_rate_is_valid(uint32_t sample_rate);
/** Tests that a blocksize at the given sample rate is valid for the FLAC
* subset.
*
* \param blocksize The blocksize to test for compliance.
* \param sample_rate The sample rate is needed, since the valid subset
* blocksize depends on the sample rate.
* \retval FLAC__bool
* \c true if the given blocksize conforms to the specification for the
* subset at the given sample rate, else \c false.
*/
FLAC_API FLAC__bool FLAC__format_blocksize_is_subset(uint32_t blocksize, uint32_t sample_rate);
/** Tests that a sample rate is valid for the FLAC subset. The subset rules
* for valid sample rates are slightly more complex since the rate has to
* be expressible completely in the frame header.
*
* \param sample_rate The sample rate to test for compliance.
* \retval FLAC__bool
* \c true if the given sample rate conforms to the specification for the
* subset, else \c false.
*/
FLAC_API FLAC__bool FLAC__format_sample_rate_is_subset(uint32_t sample_rate);
/** Check a Vorbis comment entry name to see if it conforms to the Vorbis
* comment specification.
*
* Vorbis comment names must be composed only of characters from
* [0x20-0x3C,0x3E-0x7D].
*
* \param name A NUL-terminated string to be checked.
* \assert
* \code name != NULL \endcode
* \retval FLAC__bool
* \c false if entry name is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_name_is_legal(const char *name);
/** Check a Vorbis comment entry value to see if it conforms to the Vorbis
* comment specification.
*
* Vorbis comment values must be valid UTF-8 sequences.
*
* \param value A string to be checked.
* \param length A the length of \a value in bytes. May be
* \c (uint32_t)(-1) to indicate that \a value is a plain
* UTF-8 NUL-terminated string.
* \assert
* \code value != NULL \endcode
* \retval FLAC__bool
* \c false if entry name is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_value_is_legal(const FLAC__byte *value, uint32_t length);
/** Check a Vorbis comment entry to see if it conforms to the Vorbis
* comment specification.
*
* Vorbis comment entries must be of the form 'name=value', and 'name' and
* 'value' must be legal according to
* FLAC__format_vorbiscomment_entry_name_is_legal() and
* FLAC__format_vorbiscomment_entry_value_is_legal() respectively.
*
* \param entry An entry to be checked.
* \param length The length of \a entry in bytes.
* \assert
* \code value != NULL \endcode
* \retval FLAC__bool
* \c false if entry name is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_vorbiscomment_entry_is_legal(const FLAC__byte *entry, uint32_t length);
/** Check a seek table to see if it conforms to the FLAC specification.
* See the format specification for limits on the contents of the
* seek table.
*
* \param seek_table A pointer to a seek table to be checked.
* \assert
* \code seek_table != NULL \endcode
* \retval FLAC__bool
* \c false if seek table is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_seektable_is_legal(const FLAC__StreamMetadata_SeekTable *seek_table);
/** Sort a seek table's seek points according to the format specification.
* This includes a "unique-ification" step to remove duplicates, i.e.
* seek points with identical \a sample_number values. Duplicate seek
* points are converted into placeholder points and sorted to the end of
* the table.
*
* \param seek_table A pointer to a seek table to be sorted.
* \assert
* \code seek_table != NULL \endcode
* \retval uint32_t
* The number of duplicate seek points converted into placeholders.
*/
FLAC_API uint32_t FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
/** 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 cue_sheet A pointer to an existing cue sheet to be checked.
* \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 cue_sheet != NULL \endcode
* \retval FLAC__bool
* \c false if cue sheet is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_cuesheet_is_legal(const FLAC__StreamMetadata_CueSheet *cue_sheet, FLAC__bool check_cd_da_subset, const char **violation);
/** Check picture data to see if it conforms to the FLAC specification.
* See the format specification for limits on the contents of the
* PICTURE block.
*
* \param picture A pointer to existing picture data 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 picture != NULL \endcode
* \retval FLAC__bool
* \c false if picture data is illegal, else \c true.
*/
FLAC_API FLAC__bool FLAC__format_picture_is_legal(const FLAC__StreamMetadata_Picture *picture, const char **violation);
/* \} */
#ifdef __cplusplus
}
#endif
#endif