662 lines
23 KiB
C
662 lines
23 KiB
C
/* libFLAC - Free Lossless Audio Codec library
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* Copyright (C) 2000,2001,2002 Josh Coalson
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifndef FLAC__FORMAT_H
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#define FLAC__FORMAT_H
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#include "ordinals.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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/** \file include/FLAC/format.h
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*
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* \brief
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* This module contains structure definitions for the representation
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* of FLAC format components in memory. These are the basic
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* structures used by the rest of the interfaces.
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*
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* See the detailed documentation in the
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* \link flac_format format \endlink module.
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*/
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/** \defgroup flac_format FLAC/format.h: format components
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* \ingroup flac
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*
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* \brief
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* This module contains structure definitions for the representation
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* of FLAC format components in memory. These are the basic
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* structures used by the rest of the interfaces.
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*
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* First, you should be familiar with the
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* <A HREF="../format.html">FLAC format</A>. Many of the values here
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* follow directly from the specification. As a user of libFLAC, the
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* interesting parts really are the structures that describe the frame
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* header and metadata blocks.
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*
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* The format structures here are very primitive, designed to store
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* information in an efficient way. Reading information from the
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* structures is easy but creating or modifying them directly is
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* more complex. For the most part, as a user of a library, editing
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* is not necessary; however, for metadata blocks it is, so there are
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* convenience functions provided in the \link flac_metadata metadata
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* module \endlink to simplify the manipulation of metadata blocks.
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*
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* \note
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* It's not the best convention, but symbols ending in _LEN are in bits
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* and _LENGTH are in bytes. _LENGTH symbols are \#defines instead of
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* global variables because they are usually used when declaring byte
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* arrays and some compilers require compile-time knowledge of array
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* sizes when declared on the stack.
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*
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* \{
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*/
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/*
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Most of the values described in this file are defined by the FLAC
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format specification. There is nothing to tune here.
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*/
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/** The minimum block size, in samples, permitted by the format. */
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#define FLAC__MIN_BLOCK_SIZE (16u)
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/** The maximum block size, in samples, permitted by the format. */
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#define FLAC__MAX_BLOCK_SIZE (65535u)
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/** The maximum number of channels permitted by the format. */
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#define FLAC__MAX_CHANNELS (8u)
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/** The minimum sample resolution permitted by the format. */
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#define FLAC__MIN_BITS_PER_SAMPLE (4u)
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/** The maximum sample resolution permitted by the format. */
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#define FLAC__MAX_BITS_PER_SAMPLE (32u)
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/** The maximum sample resolution permitted by libFLAC.
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*
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* \warning
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* FLAC__MAX_BITS_PER_SAMPLE is the limit of the FLAC format. However,
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* the reference encoder/decoder is currently limited to 24 bits because
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* of prevalent 32-bit math, so make sure and use this value when
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* appropriate.
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*/
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#define FLAC__REFERENCE_CODEC_MAX_BITS_PER_SAMPLE (24u)
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/** The maximum sample rate permitted by the format. The value is
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* ((2 ^ 16) - 1) * 10; see <A HREF="../format.html">FLAC format</A>
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* as to why.
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*/
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#define FLAC__MAX_SAMPLE_RATE (655350u)
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/** The maximum LPC order permitted by the format. */
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#define FLAC__MAX_LPC_ORDER (32u)
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/** The minimum quantized linear predictor coefficient precision
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* permitted by the format.
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*/
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#define FLAC__MIN_QLP_COEFF_PRECISION (5u)
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/** The maximum order of the fixed predictors permitted by the format. */
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#define FLAC__MAX_FIXED_ORDER (4u)
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/** The maximum Rice partition order permitted by the format. */
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#define FLAC__MAX_RICE_PARTITION_ORDER (15u)
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/* VERSION should come from configure */
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#ifdef VERSION
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/** The version string of the current library.
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*
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* \note
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* This does not correspond to the shared library version number, which
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* is used to determine binary compatibility.
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*/
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#define FLAC__VERSION_STRING VERSION
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#endif
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/** The vendor string inserted by the encoder into the VORBIS_COMMENT block.
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* This is a nulL-terminated ASCII string; when inserted into the
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* VORBIS_COMMENT the trailing null is stripped.
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*/
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extern const FLAC__byte *FLAC__VENDOR_STRING;
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/** The byte string representation of the beginning of a FLAC stream. */
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extern const FLAC__byte FLAC__STREAM_SYNC_STRING[4]; /* = "fLaC" */
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/** The 32-bit integer big-endian representation of the beginning of
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* a FLAC stream.
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*/
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extern const unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */
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/** The length of the FLAC signature in bits. */
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extern const unsigned FLAC__STREAM_SYNC_LEN; /* = 32 bits */
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/** The length of the FLAC signature in bytes. */
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#define FLAC__STREAM_SYNC_LENGTH (4u)
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/*****************************************************************************
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*
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* Subframe structures
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*
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*****************************************************************************/
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/*****************************************************************************/
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/** An enumeration of the available entropy coding methods. */
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typedef enum {
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FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0
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/**< Residual is coded by partitioning into contexts, each with it's own
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* Rice parameter. */
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} FLAC__EntropyCodingMethodType;
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/** Maps a FLAC__EntropyCodingMethodType to a C string.
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*
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* Using a FLAC__EntropyCodingMethodType as the index to this array will
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* give the string equivalent. The contents should not be modified.
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*/
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extern const char * const FLAC__EntropyCodingMethodTypeString[];
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/** Contents of a Rice partitioned residual
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*/
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typedef struct {
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unsigned *parameters;
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/**< The Rice parameters for each context. */
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unsigned *raw_bits;
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/**< Widths for escape-coded partitions. */
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unsigned capacity_by_order;
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/**< The capacity of the \a parameters and \a raw_bits arrays
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* specified as an order, i.e. the number of array elements
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* allocated is 2 ^ \a capacity_by_order.
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*/
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} FLAC__EntropyCodingMethod_PartitionedRiceContents;
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/** Header for a Rice partitioned residual. (c.f. <A HREF="../format.html#partitioned_rice">format specification</A>)
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*/
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typedef struct {
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unsigned order;
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/**< The partition order, i.e. # of contexts = 2 ^ \a order. */
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const FLAC__EntropyCodingMethod_PartitionedRiceContents *contents;
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/**< The context's Rice parameters and/or raw bits. */
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} FLAC__EntropyCodingMethod_PartitionedRice;
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extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /**< == 5 (bits) */
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extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER;
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/**< == (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
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/** Header for the entropy coding method. (c.f. <A HREF="../format.html#residual">format specification</A>)
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*/
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typedef struct {
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FLAC__EntropyCodingMethodType type;
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union {
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FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
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} data;
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} FLAC__EntropyCodingMethod;
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extern const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /**< == 2 (bits) */
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/*****************************************************************************/
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/** An enumeration of the available subframe types. */
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typedef enum {
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FLAC__SUBFRAME_TYPE_CONSTANT = 0, /**< constant signal */
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FLAC__SUBFRAME_TYPE_VERBATIM = 1, /**< uncompressed signal */
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FLAC__SUBFRAME_TYPE_FIXED = 2, /**< fixed polynomial prediction */
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FLAC__SUBFRAME_TYPE_LPC = 3 /**< linear prediction */
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} FLAC__SubframeType;
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/** Maps a FLAC__SubframeType to a C string.
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*
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* Using a FLAC__SubframeType as the index to this array will
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* give the string equivalent. The contents should not be modified.
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*/
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extern const char * const FLAC__SubframeTypeString[];
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/** CONSTANT subframe. (c.f. <A HREF="../format.html#subframe_constant">format specification</A>)
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*/
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typedef struct {
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FLAC__int32 value; /**< The constant signal value. */
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} FLAC__Subframe_Constant;
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/** VERBATIM subframe. (c.f. <A HREF="../format.html#subframe_verbatim">format specification</A>)
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*/
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typedef struct {
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const FLAC__int32 *data; /**< A pointer to verbatim signal. */
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} FLAC__Subframe_Verbatim;
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/** FIXED subframe. (c.f. <A HREF="../format.html#subframe_fixed">format specification</A>)
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*/
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typedef struct {
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FLAC__EntropyCodingMethod entropy_coding_method;
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/**< The residual coding method. */
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unsigned order;
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/**< The polynomial order. */
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FLAC__int32 warmup[FLAC__MAX_FIXED_ORDER];
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/**< Warmup samples to prime the predictor, length == order. */
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const FLAC__int32 *residual;
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/**< The residual signal, length == (blocksize minus order) samples. */
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} FLAC__Subframe_Fixed;
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/** LPC subframe. (c.f. <A HREF="../format.html#subframe_lpc">format specification</A>)
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*/
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typedef struct {
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FLAC__EntropyCodingMethod entropy_coding_method;
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/**< The residual coding method. */
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unsigned order;
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/**< The FIR order. */
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unsigned qlp_coeff_precision;
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/**< Quantized FIR filter coefficient precision in bits. */
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int quantization_level;
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/**< The qlp coeff shift needed. */
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FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
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/**< FIR filter coefficients. */
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FLAC__int32 warmup[FLAC__MAX_LPC_ORDER];
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/**< Warmup samples to prime the predictor, length == order. */
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const FLAC__int32 *residual;
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/**< The residual signal, length == (blocksize minus order) samples. */
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} FLAC__Subframe_LPC;
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extern const unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /**< == 5 (bits) */
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/** FLAC subframe structure. (c.f. <A HREF="../format.html#subframe">format specification</A>)
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*/
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typedef struct {
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FLAC__SubframeType type;
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union {
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FLAC__Subframe_Constant constant;
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FLAC__Subframe_Fixed fixed;
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FLAC__Subframe_LPC lpc;
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FLAC__Subframe_Verbatim verbatim;
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} data;
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unsigned wasted_bits;
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} FLAC__Subframe;
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extern const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN; /**< == 1 (bit) */
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extern const unsigned FLAC__SUBFRAME_TYPE_LEN; /**< == 6 (bits) */
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extern const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /**< == 1 (bit) */
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extern const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /* = 0x00 */
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extern const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /* = 0x02 */
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extern const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /* = 0x10 */
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extern const unsigned FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK; /* = 0x40 */
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/*****************************************************************************/
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/*****************************************************************************
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*
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* Frame structures
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*
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*****************************************************************************/
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/** An enumeration of the available channel assignments. */
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typedef enum {
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FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT = 0, /**< independent channels */
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FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE = 1, /**< left+side stereo */
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FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE = 2, /**< right+side stereo */
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FLAC__CHANNEL_ASSIGNMENT_MID_SIDE = 3 /**< mid+side stereo */
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} FLAC__ChannelAssignment;
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/** Maps a FLAC__ChannelAssignment to a C string.
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*
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* Using a FLAC__ChannelAssignment as the index to this array will
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* give the string equivalent. The contents should not be modified.
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*/
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extern const char * const FLAC__ChannelAssignmentString[];
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/** An enumeration of the possible frame numbering methods. */
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typedef enum {
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FLAC__FRAME_NUMBER_TYPE_FRAME_NUMBER, /**< number contains the frame number */
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FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER /**< number contains the sample number of first sample in frame */
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} FLAC__FrameNumberType;
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/** Maps a FLAC__FrameNumberType to a C string.
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*
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* Using a FLAC__FrameNumberType as the index to this array will
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* give the string equivalent. The contents should not be modified.
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*/
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extern const char * const FLAC__FrameNumberTypeString[];
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/** FLAC frame header structure. (c.f. <A HREF="../format.html#frame_header">format specification</A>)
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*/
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typedef struct {
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unsigned blocksize;
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/**< The number of samples per subframe. */
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unsigned sample_rate;
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/**< The sample rate in Hz. */
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unsigned channels;
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/**< The number of channels (== number of subframes). */
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FLAC__ChannelAssignment channel_assignment;
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/**< The channel assignment for the frame. */
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unsigned bits_per_sample;
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/**< The sample resolution. */
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FLAC__FrameNumberType number_type;
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/**< The numbering scheme used for the frame. */
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union {
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FLAC__uint32 frame_number;
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FLAC__uint64 sample_number;
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} number;
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/**< The frame number or sample number of first sample in frame;
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* use the \a number_type value to determine which to use. */
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FLAC__uint8 crc;
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/**< CRC-8 (polynomial = x^8 + x^2 + x^1 + x^0, initialized with 0)
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* of the raw frame header bytes, meaning everything before the CRC byte
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* including the sync code.
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*/
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} FLAC__FrameHeader;
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extern const unsigned FLAC__FRAME_HEADER_SYNC; /**< == 0x3ffe; the frame header sync code */
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extern const unsigned FLAC__FRAME_HEADER_SYNC_LEN; /**< == 14 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_RESERVED_LEN; /**< == 2 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /**< == 4 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /**< == 3 (bits) */
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extern const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN; /**< == 1 (bit) */
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extern const unsigned FLAC__FRAME_HEADER_CRC_LEN; /**< == 8 (bits) */
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/** FLAC frame footer structure. (c.f. <A HREF="../format.html#frame_footer">format specification</A>)
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*/
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typedef struct {
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FLAC__uint16 crc;
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/**< CRC-16 (polynomial = x^16 + x^15 + x^2 + x^0, initialized with
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* 0) of the bytes before the crc, back to and including the frame header
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* sync code.
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*/
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} FLAC__FrameFooter;
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extern const unsigned FLAC__FRAME_FOOTER_CRC_LEN; /**< == 16 (bits) */
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/** FLAC frame structure. (c.f. <A HREF="../format.html#frame">format specification</A>)
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*/
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typedef struct {
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FLAC__FrameHeader header;
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FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
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FLAC__FrameFooter footer;
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} FLAC__Frame;
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/*****************************************************************************/
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/*****************************************************************************
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*
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* Meta-data structures
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*
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*****************************************************************************/
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/** An enumeration of the available metadata block types. */
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typedef enum {
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FLAC__METADATA_TYPE_STREAMINFO = 0,
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/**< <A HREF="../format.html#metadata_block_streaminfo">STREAMINFO</A> block */
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FLAC__METADATA_TYPE_PADDING = 1,
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/**< <A HREF="../format.html#metadata_block_padding"PADDING</A> block */
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FLAC__METADATA_TYPE_APPLICATION = 2,
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/**< <A HREF="../format.html#metadata_block_application"APPLICATION</A> block */
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FLAC__METADATA_TYPE_SEEKTABLE = 3,
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/**< <A HREF="../format.html#metadata_block_seektable"SEEKTABLE</A> block */
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FLAC__METADATA_TYPE_VORBIS_COMMENT = 4,
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/**< <A HREF="../format.html#metadata_block_vorbis_comment"VORBISCOMMENT</A> block */
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} FLAC__MetadataType;
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/** Maps a FLAC__MetadataType to a C string.
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*
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* Using a FLAC__MetadataType as the index to this array will
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* give the string equivalent. The contents should not be modified.
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*/
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extern const char * const FLAC__MetadataTypeString[];
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/** FLAC STREAMINFO structure. (c.f. <A HREF="../format.html#metadata_block_streaminfo">format specification</A>)
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*/
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typedef struct {
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unsigned min_blocksize, max_blocksize;
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unsigned min_framesize, max_framesize;
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unsigned sample_rate;
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unsigned channels;
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unsigned bits_per_sample;
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FLAC__uint64 total_samples;
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FLAC__byte md5sum[16];
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} FLAC__StreamMetadata_StreamInfo;
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /**< == 16 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /**< == 16 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /**< == 24 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /**< == 24 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /**< == 20 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /**< == 3 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /**< == 5 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /**< == 36 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /**< == 128 (bits) */
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/** The total stream length of the STREAMINFO block in bytes. */
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#define FLAC__STREAM_METADATA_STREAMINFO_LENGTH (34u)
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/** FLAC PADDING structure. (c.f. <A HREF="../format.html#metadata_block_padding">format specification</A>)
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|
*/
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typedef struct {
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int dummy;
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/**< Conceptually this is an empty struct since we don't store the
|
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* padding bytes. Empty structs are not allowed by some C compilers,
|
|
* hence the dummy.
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|
*/
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} FLAC__StreamMetadata_Padding;
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|
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/** FLAC APPLICATION structure. (c.f. <A HREF="../format.html#metadata_block_application">format specification</A>)
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*/
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typedef struct {
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|
FLAC__byte id[4];
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FLAC__byte *data;
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} FLAC__StreamMetadata_Application;
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extern const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /**< == 32 (bits) */
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/** SeekPoint structure used in SEEKTABLE blocks. (c.f. <A HREF="../format.html#seekpoint">format specification</A>)
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*/
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typedef struct {
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FLAC__uint64 sample_number;
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/**< The sample number of the target frame. */
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|
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FLAC__uint64 stream_offset;
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/**< The offset, in bytes, of the target frame with respect to
|
|
* beginning of the first frame. */
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|
|
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unsigned frame_samples;
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/**< The number of samples in the target frame. */
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} FLAC__StreamMetadata_SeekPoint;
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|
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extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /**< == 64 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /**< == 64 (bits) */
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extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /**< == 16 (bits) */
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|
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/** The total stream length of a seek point in bytes. */
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#define FLAC__STREAM_METADATA_SEEKPOINT_LENGTH (18u)
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|
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/** The value used in the \a sample_number field of
|
|
* FLAC__StreamMetadataSeekPoint used to indicate a placeholder
|
|
* point (== 0xffffffffffffffff).
|
|
*/
|
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extern const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
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|
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|
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/** 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;
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|
|
|
|
/** 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 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 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 const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /**< == 1 (bit) */
|
|
extern const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /**< == 7 (bits) */
|
|
extern 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__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__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.
|
|
*/
|
|
unsigned FLAC__format_seektable_sort(FLAC__StreamMetadata_SeekTable *seek_table);
|
|
|
|
/* \} */
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif
|