mirror of https://github.com/xiph/flac
668 lines
24 KiB
C
668 lines
24 KiB
C
/* libFLAC - Free Lossless Audio Codec library
|
|
* Copyright (C) 2000,2001,2002 Josh Coalson
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Library General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#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="../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 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 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.
|
|
*
|
|
* \warning
|
|
* FLAC__MAX_BITS_PER_SAMPLE is the limit of the FLAC format. However,
|
|
* the reference encoder/decoder is currently limited to 24 bits because
|
|
* of prevalent 32-bit math, so make sure and use this value when
|
|
* appropriate.
|
|
*/
|
|
#define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (24u)
|
|
|
|
/** The maximum sample rate permitted by the format. The value is
|
|
* ((2 ^ 16) - 1) * 10; see <A HREF="../format.html">FLAC format</A>
|
|
* as to why.
|
|
*/
|
|
#define FLAC__MAX_SAMPLE_RATE (655350u)
|
|
|
|
/** The maximum LPC order permitted by the format. */
|
|
#define FLAC__MAX_LPC_ORDER (32u)
|
|
|
|
/** 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 nulL-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 unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */
|
|
|
|
/** The length of the FLAC signature in bits. */
|
|
extern FLAC_API const unsigned 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
|
|
* 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 {
|
|
|
|
unsigned *parameters;
|
|
/**< The Rice parameters for each context. */
|
|
|
|
unsigned *raw_bits;
|
|
/**< Widths for escape-coded partitions. */
|
|
|
|
unsigned 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="../format.html#partitioned_rice">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
|
|
unsigned 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 unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /**< == 5 (bits) */
|
|
|
|
extern FLAC_API const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;
|
|
/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
|
|
|
|
/** Header for the entropy coding method. (c.f. <A HREF="../format.html#residual">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__EntropyCodingMethodType type;
|
|
union {
|
|
FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
|
|
} data;
|
|
} FLAC__EntropyCodingMethod;
|
|
|
|
extern FLAC_API const unsigned 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="../format.html#subframe_constant">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__int32 value; /**< The constant signal value. */
|
|
} FLAC__Subframe_Constant;
|
|
|
|
|
|
/** VERBATIM subframe. (c.f. <A HREF="../format.html#subframe_verbatim">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
const FLAC__int32 *data; /**< A pointer to verbatim signal. */
|
|
} FLAC__Subframe_Verbatim;
|
|
|
|
|
|
/** FIXED subframe. (c.f. <A HREF="../format.html#subframe_fixed">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__EntropyCodingMethod entropy_coding_method;
|
|
/**< The residual coding method. */
|
|
|
|
unsigned order;
|
|
/**< The polynomial order. */
|
|
|
|
FLAC__int32 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="../format.html#subframe_lpc">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__EntropyCodingMethod entropy_coding_method;
|
|
/**< The residual coding method. */
|
|
|
|
unsigned order;
|
|
/**< The FIR order. */
|
|
|
|
unsigned 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__int32 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 unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /**< == 5 (bits) */
|
|
|
|
|
|
/** FLAC subframe structure. (c.f. <A HREF="../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;
|
|
unsigned wasted_bits;
|
|
} FLAC__Subframe;
|
|
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN; /**< == 1 (bit) */
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_LEN; /**< == 6 (bits) */
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /**< == 1 (bit) */
|
|
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /* = 0x00 */
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /* = 0x02 */
|
|
extern FLAC_API const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /* = 0x10 */
|
|
extern FLAC_API const unsigned 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="../format.html#frame_header">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
unsigned blocksize;
|
|
/**< The number of samples per subframe. */
|
|
|
|
unsigned sample_rate;
|
|
/**< The sample rate in Hz. */
|
|
|
|
unsigned channels;
|
|
/**< The number of channels (== number of subframes). */
|
|
|
|
FLAC__ChannelAssignment channel_assignment;
|
|
/**< The channel assignment for the frame. */
|
|
|
|
unsigned bits_per_sample;
|
|
/**< The sample resolution. */
|
|
|
|
FLAC__FrameNumberType number_type;
|
|
/**< The numbering scheme used for the frame. */
|
|
|
|
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 unsigned FLAC__FRAME_HEADER_SYNC; /**< == 0x3ffe; the frame header sync code */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_SYNC_LEN; /**< == 14 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_RESERVED_LEN; /**< == 2 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /**< == 4 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /**< == 3 (bits) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN; /**< == 1 (bit) */
|
|
extern FLAC_API const unsigned FLAC__FRAME_HEADER_CRC_LEN; /**< == 8 (bits) */
|
|
|
|
|
|
/** FLAC frame footer structure. (c.f. <A HREF="../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 unsigned FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
|
|
|
|
|
|
/** FLAC frame structure. (c.f. <A HREF="../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="../format.html#metadata_block_streaminfo">STREAMINFO</A> block */
|
|
|
|
FLAC__METADATA_TYPE_PADDING = 1,
|
|
/**< <A HREF="../format.html#metadata_block_padding"PADDING</A> block */
|
|
|
|
FLAC__METADATA_TYPE_APPLICATION = 2,
|
|
/**< <A HREF="../format.html#metadata_block_application"APPLICATION</A> block */
|
|
|
|
FLAC__METADATA_TYPE_SEEKTABLE = 3,
|
|
/**< <A HREF="../format.html#metadata_block_seektable"SEEKTABLE</A> block */
|
|
|
|
FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
|
|
/**< <A HREF="../format.html#metadata_block_vorbis_comment"VORBISCOMMENT</A> 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="../format.html#metadata_block_streaminfo">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
unsigned min_blocksize, max_blocksize;
|
|
unsigned min_framesize, max_framesize;
|
|
unsigned sample_rate;
|
|
unsigned channels;
|
|
unsigned bits_per_sample;
|
|
FLAC__uint64 total_samples;
|
|
FLAC__byte md5sum[16];
|
|
} FLAC__StreamMetadata_StreamInfo;
|
|
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
|
|
extern FLAC_API const unsigned 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="../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="../format.html#metadata_block_application">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__byte id[4];
|
|
FLAC__byte *data;
|
|
} FLAC__StreamMetadata_Application;
|
|
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
|
|
|
|
/** SeekPoint structure used in SEEKTABLE blocks. (c.f. <A HREF="../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. */
|
|
|
|
unsigned frame_samples;
|
|
/**< The number of samples in the target frame. */
|
|
} FLAC__StreamMetadata_SeekPoint;
|
|
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
|
|
extern FLAC_API const unsigned 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="../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 {
|
|
unsigned num_points;
|
|
FLAC__StreamMetadata_SeekPoint *points;
|
|
} FLAC__StreamMetadata_SeekTable;
|
|
|
|
|
|
/** Vorbis comment entry structure used in VORBIS_COMMENT blocks. (c.f. <A HREF="../format.html#metadata_block_vorbis_comment">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__uint32 length;
|
|
FLAC__byte *entry;
|
|
} FLAC__StreamMetadata_VorbisComment_Entry;
|
|
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN; /**< == 32 (bits) */
|
|
|
|
|
|
/** FLAC VORBIS_COMMENT structure. (c.f. <A HREF="../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 unsigned FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN; /**< == 32 (bits) */
|
|
|
|
|
|
/** FLAC metadata block structure. (c.f. <A HREF="../format.html#metadata_block">format specification</A>)
|
|
*/
|
|
typedef struct {
|
|
FLAC__MetadataType type;
|
|
/**< The type of the metadata block; used determine which member of the
|
|
* \a data union to dereference. */
|
|
|
|
FLAC__bool is_last;
|
|
/**< \c true if this metadata block is the last, else \a false */
|
|
|
|
unsigned 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;
|
|
} data;
|
|
/**< Polymorphic block data; use the \a type value to determine which
|
|
* to use. */
|
|
} FLAC__StreamMetadata;
|
|
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
|
|
extern FLAC_API const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
|
|
extern FLAC_API const unsigned 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. Since the rules for valid
|
|
* sample rates are slightly complex, they are encapsulated in this function.
|
|
*
|
|
* \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(unsigned sample_rate);
|
|
|
|
/** 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 unsigned
|
|
* The number of duplicate seek points converted into placeholders.
|
|
*/
|
|
FLAC_API unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
|
|
|
|
/* \} */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|