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6f9603eaee
flac/include/FLAC/format.h
Josh Coalson 6f9603eaee add number_type to frame header
2001-07-16 18:02:32 +00:00

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18 KiB
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/* libFLAC - Free Lossless Audio Codec library
* Copyright (C) 2000,2001 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 "ordinals.h"
/* changing the following values to be higher will break the framing and hence the stream format, so DON'T! */
#define FLAC__MIN_BLOCK_SIZE (16u)
#define FLAC__MAX_BLOCK_SIZE (65535u)
#define FLAC__MAX_CHANNELS (8u)
#define FLAC__MIN_BITS_PER_SAMPLE (4u)
/*NOTE: only up to 24 because of the current predictor coefficient quantization and the fact we use FLAC__int32s for all work */
#define FLAC__MAX_BITS_PER_SAMPLE (24u)
/* the following is ((2 ** 20) - 1) div 10 */
#define FLAC__MAX_SAMPLE_RATE (1048570u)
#define FLAC__MAX_LPC_ORDER (32u)
#define FLAC__MIN_QLP_COEFF_PRECISION (5u)
/* changing FLAC__MAX_FIXED_ORDER also means changing all of fixed.c and more, so DON'T! */
#define FLAC__MAX_FIXED_ORDER (4u)
#define FLAC__MAX_RICE_PARTITION_ORDER (15u)
/* VERSION should come from configure */
#ifdef VERSION
#define FLAC__VERSION_STRING VERSION
#endif
extern const FLAC__byte FLAC__STREAM_SYNC_STRING[4]; /* = "fLaC" */;
extern const unsigned FLAC__STREAM_SYNC; /* = 0x664C6143 */;
extern const unsigned FLAC__STREAM_SYNC_LEN; /* = 32 bits */;
/*****************************************************************************
*
* NOTE: Within the bitstream, all fixed-width numbers are big-endian coded.
* All numbers are unsigned unless otherwise noted.
*
*****************************************************************************/
/*****************************************************************************
*
* Subframe structures
*
*****************************************************************************/
/*****************************************************************************/
typedef enum {
FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE = 0
} FLAC__EntropyCodingMethodType;
extern const char *FLAC__EntropyCodingMethodTypeString[];
/*****************************************************************************
*
* 4: partition order => (2 ** order) subdivisions
*/
typedef struct {
unsigned order;
unsigned parameters[1 << FLAC__MAX_RICE_PARTITION_ORDER];
unsigned raw_bits[1 << FLAC__MAX_RICE_PARTITION_ORDER];
} FLAC__EntropyCodingMethod_PartitionedRice;
extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN; /* = 4 bits */
extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN; /* = 4 bits */
extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN; /* = 5 bits */
extern const unsigned FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER; /* = (1<<FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN)-1 */
/*****************************************************************************
*
* 2: entropy coding method:
* 00: partitioned rice coding
* 01-11: reserved
* ?: entropy coding method data
*/
typedef struct {
FLAC__EntropyCodingMethodType type;
union {
FLAC__EntropyCodingMethod_PartitionedRice partitioned_rice;
} data;
} FLAC__EntropyCodingMethod;
extern const unsigned FLAC__ENTROPY_CODING_METHOD_TYPE_LEN; /* = 2 bits */
/*****************************************************************************/
typedef enum {
FLAC__SUBFRAME_TYPE_CONSTANT = 0,
FLAC__SUBFRAME_TYPE_VERBATIM = 1,
FLAC__SUBFRAME_TYPE_FIXED = 2,
FLAC__SUBFRAME_TYPE_LPC = 3
} FLAC__SubframeType;
extern const char *FLAC__SubframeTypeString[];
/*****************************************************************************
*
* n: constant value for signal; n = frame's bits-per-sample
*/
typedef struct {
FLAC__int32 value;
} FLAC__Subframe_Constant;
/*****************************************************************************
*
* n*i: unencoded signal; n = frame's bits-per-sample, i = frame's blocksize
*/
typedef struct {
const FLAC__int32 *data;
} FLAC__Subframe_Verbatim;
/*****************************************************************************
*
* n: unencoded warm-up samples (n = fixed-predictor order * bits per sample)
* ?: entropy coding method info
* ?: encoded residual ((blocksize minus fixed-predictor order) samples)
* The order is stored in the main subframe header
*/
typedef struct {
FLAC__EntropyCodingMethod entropy_coding_method;
unsigned order;
FLAC__int32 warmup[FLAC__MAX_FIXED_ORDER];
const FLAC__int32 *residual;
} FLAC__Subframe_Fixed;
/*****************************************************************************
*
* n: unencoded warm-up samples (n = lpc order * bits per sample)
* 4: (qlp coeff precision in bits)-1 (1111 = invalid, use to check for erroneous sync)
* 5: qlp shift needed in bits (signed)
* n: unencoded predictor coefficients (n = lpc order * qlp coeff precision)
* ?: entropy coding method info
* ?: encoded residual ((blocksize minus lpc order) samples)
* The order is stored in the main subframe header
*/
typedef struct {
FLAC__EntropyCodingMethod entropy_coding_method;
unsigned order;
unsigned qlp_coeff_precision;
int quantization_level;
FLAC__int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
FLAC__int32 warmup[FLAC__MAX_LPC_ORDER];
const FLAC__int32 *residual;
} FLAC__Subframe_LPC;
extern const unsigned FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN; /* = 4 bits */
extern const unsigned FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN; /* = 5 bits */
/*****************************************************************************
*
* 1: zero pad, to prevent sync-fooling string of 1s (use to check for erroneous sync)
* 6: subframe type
* 000000: constant value
* 000001: verbatim
* 00001x: reserved
* 0001xx: reserved
* 001xxx: fixed predictor, xxx=order <= 4, else reserved
* 01xxxx: reserved
* 1xxxxx: lpc, xxxxx=order-1
* 1: 'wasted bits' flag
* 0: no wasted bits in source subblock
* 1: all samples in source subblock contain n 0 least significant bits. n-1 follows, unary coded, i.e. n=3, 001 follows, n=7, 0000001 follows.
* ?: unary coded (n-1)
* ?: subframe-specific data (c.f. FLAC__Subframe_*)
*/
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 const unsigned FLAC__SUBFRAME_ZERO_PAD_LEN; /* = 1 bit */
extern const unsigned FLAC__SUBFRAME_TYPE_LEN; /* = 6 bits */
extern const unsigned FLAC__SUBFRAME_WASTED_BITS_FLAG_LEN; /* = 1 bit */
extern const unsigned FLAC__SUBFRAME_TYPE_CONSTANT_BYTE_ALIGNED_MASK; /* = 0x00 */
extern const unsigned FLAC__SUBFRAME_TYPE_VERBATIM_BYTE_ALIGNED_MASK; /* = 0x02 */
extern const unsigned FLAC__SUBFRAME_TYPE_FIXED_BYTE_ALIGNED_MASK; /* = 0x10 */
extern const unsigned FLAC__SUBFRAME_TYPE_LPC_BYTE_ALIGNED_MASK; /* = 0x40 */
/*****************************************************************************/
/*****************************************************************************
*
* Frame structures
*
*****************************************************************************/
typedef enum {
FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT = 0,
FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE = 1,
FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE = 2,
FLAC__CHANNEL_ASSIGNMENT_MID_SIDE = 3
} FLAC__ChannelAssignment;
extern const char *FLAC__ChannelAssignmentString[];
typedef enum {
FLAC__FRAME_NUMBER_TYPE_FRAME_NUMBER,
FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER
} FLAC__FrameNumberType;
extern const char *FLAC__FrameNumberTypeString[];
/*****************************************************************************
*
* 14: sync code '11111111111110'
* 2: reserved
* 00: currently required value
* 01-11: reserved
* 4: blocksize in samples
* 0000: get from stream header => implies constant blocksize throughout stream
* 0001: 192 samples (AES/EBU) => implies constant blocksize throughout stream
* 0010-0101: 576 * (2^(n-2)) samples, i.e. 576/1152/2304/4608 => implies constant blocksize throughout stream
* 0110: get 8 bit (blocksize-1) from end of header => possibly variable blocksize throughout stream unless it's the last frame
* 0111: get 16 bit (blocksize-1) from end of header => possibly variable blocksize throughout stream unless it's the last frame
* 1000-1111: 256 * (2^(n-8)) samples, i.e. 256/512/1024/2048/4096/8192/16384/32768 => implies constant blocksize throughout stream
* 4: sample rate:
* 0000: get from stream header
* 0001-0011: reserved
* 0100: 8kHz
* 0101: 16kHz
* 0110: 22.05kHz
* 0111: 24kHz
* 1000: 32kHz
* 1001: 44.1kHz
* 1010: 48kHz
* 1011: 96kHz
* 1100: get 8 bit sample rate (in kHz) from end of header
* 1101: get 16 bit sample rate (in Hz) from end of header
* 1110: get 16 bit sample rate (in tens of Hz) from end of header
* 1111: invalid, to prevent sync-fooling string of 1s (use to check for erroneous sync)
* 4: channel assignment
* 0000-0111: (number of independent channels)-1. when == 0001, channel 0 is the left channel and channel 1 is the right
* 1000: left/side stereo : channel 0 is the left channel, channel 1 is the side(difference) channel
* 1001: right/side stereo: channel 0 is the side(difference) channel, channel 1 is the right channel
* 1010: mid/side stereo : channel 0 is the mid(average) channel, channel 1 is the side(difference) channel
* 1011-1111: reserved
* 3: sample size in bits
* 000: get from stream header
* 001: 8 bits per sample
* 010: 12 bits per sample
* 011: reserved
* 100: 16 bits per sample
* 101: 20 bits per sample
* 110: 24 bits per sample
* 111: reserved
* 1: zero pad, to prevent sync-fooling string of 1s (use to check for erroneous sync)
* ?: if(variable blocksize)
* 8-56: 'UTF-8' coded sample number (decoded number is 0-36 bits) (use to check for erroneous sync)
* else
* 8-48: 'UTF-8' coded frame number (decoded number is 0-31 bits) (use to check for erroneous sync)
* ?: if(blocksize bits == 11x)
* 8/16 bit (blocksize-1)
* ?: if(sample rate bits == 11xx)
* 8/16 bit sample rate
* 8: CRC-8 (polynomial = x^8 + x^2 + x^1 + x^0, initialized with 0) of everything before the crc, including the sync code
*/
typedef struct {
unsigned blocksize; /* in samples */
unsigned sample_rate; /* in Hz */
unsigned channels;
FLAC__ChannelAssignment channel_assignment;
unsigned bits_per_sample;
FLAC__FrameNumberType number_type;
union {
FLAC__uint32 frame_number;
FLAC__uint64 sample_number;
} number;
FLAC__uint8 crc;
} FLAC__FrameHeader;
extern const unsigned FLAC__FRAME_HEADER_SYNC; /* = 0x3ffe */
extern const unsigned FLAC__FRAME_HEADER_SYNC_LEN; /* = 14 bits */
extern const unsigned FLAC__FRAME_HEADER_RESERVED_LEN; /* = 2 bits */
extern const unsigned FLAC__FRAME_HEADER_BLOCK_SIZE_LEN; /* = 4 bits */
extern const unsigned FLAC__FRAME_HEADER_SAMPLE_RATE_LEN; /* = 4 bits */
extern const unsigned FLAC__FRAME_HEADER_CHANNEL_ASSIGNMENT_LEN; /* = 4 bits */
extern const unsigned FLAC__FRAME_HEADER_BITS_PER_SAMPLE_LEN; /* = 3 bits */
extern const unsigned FLAC__FRAME_HEADER_ZERO_PAD_LEN; /* = 1 bit */
extern const unsigned FLAC__FRAME_HEADER_CRC_LEN; /* = 8 bits */
/*****************************************************************************
*
* 16: CRC-16 (polynomial = x^16 + x^15 + x^2 + x^0, initialized with 0) of everything before the crc, back to and including the frame header sync code
*/
typedef struct {
FLAC__uint16 crc;
} FLAC__FrameFooter;
extern const unsigned FLAC__FRAME_FOOTER_CRC_LEN; /* = 16 bits */
typedef struct {
FLAC__FrameHeader header;
FLAC__Subframe subframes[FLAC__MAX_CHANNELS];
FLAC__FrameFooter footer;
} FLAC__Frame;
/*****************************************************************************/
/*****************************************************************************
*
* Meta-data structures
*
*****************************************************************************/
typedef enum {
FLAC__METADATA_TYPE_STREAMINFO = 0,
FLAC__METADATA_TYPE_PADDING = 1,
FLAC__METADATA_TYPE_APPLICATION = 2,
FLAC__METADATA_TYPE_SEEKTABLE = 3
} FLAC__MetaDataType;
extern const char *FLAC__MetaDataTypeString[];
/*****************************************************************************
*
* 16: minimum blocksize (in samples) of all blocks in the stream
* 16: maximum blocksize (in samples) of all blocks in the stream
* 24: minimum framesize (in bytes) of all frames in the stream; 0 => unknown
* 24: maximum framesize (in bytes) of all frames in the stream; 0 => unknown
* 20: sample rate in Hz, 0 is invalid
* 3: (number of channels)-1
* 5: (bits per sample)-1
* 36: total samples, 0 => unknown
*128: MD5 digest of the original unencoded audio data
*---- -----------------
* 34 bytes total
*/
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 const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN; /* = 16 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN; /* = 16 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN; /* = 24 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN; /* = 24 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN; /* = 20 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN; /* = 3 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN; /* = 5 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN; /* = 36 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_MD5SUM_LEN; /* = 128 bits */
extern const unsigned FLAC__STREAM_METADATA_STREAMINFO_LENGTH; /* = 34 bytes */
/*****************************************************************************
*
* n: '0' bits
*----- -----------------
* n/8 bytes total
*/
typedef struct {
int dummy; /* conceptually this is an empty struct since we don't store the padding bytes */
/* empty structs are allowed by C++ but not C, hence the 'dummy' */
} FLAC__StreamMetaData_Padding;
/*****************************************************************************
*
* 32: Registered application ID
* n: Application data
*------- -----------------
* 4+n/8 bytes total
*/
typedef struct {
FLAC__byte id[4];
FLAC__byte *data;
} FLAC__StreamMetaData_Application;
extern const unsigned FLAC__STREAM_METADATA_APPLICATION_ID_LEN; /* = 32 bits */
/*****************************************************************************
*
* 64: sample number of target frame
* 64: offset, in bytes, of target frame with respect to beginning of first frame
* 16: number of samples in the target frame
*----- -----------------
* 18 bytes total
*/
typedef struct {
FLAC__uint64 sample_number;
FLAC__uint64 stream_offset;
unsigned frame_samples;
} FLAC__StreamMetaData_SeekPoint;
extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN; /* = 64 bits */
extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN; /* = 64 bits */
extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN; /* = 16 bits */
extern const unsigned FLAC__STREAM_METADATA_SEEKPOINT_LEN; /* = 18 bytes */
extern const FLAC__uint64 FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER; /* = 0xffffffffffffffff */
/*****************************************************************************
*
* 0: num_points is implied by the metadata block 'length' field (i.e. num_points = length / 18)
* n*18*8: seek points (n = num_points, 18 is the size of a seek point in bytes)
* ------- -----------------
* n*18 bytes total
*
* NOTE: the seek points must be sorted by ascending sample number.
* NOTE: each seek point's sample number must be the first sample of the target frame.
* NOTE: each seek point's sample number must be unique within the table.
* NOTE: existence of a SEEKTABLE block implies a correct setting of total_samples in the stream_info block.
* NOTE: 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;
/*****************************************************************************
*
* 1: =1 if this is the last meta-data block, else =0
* 7: meta-data type (c.f. FLAC__MetaDataType)
* 24: length (in bytes) of the block-specific data to follow
*---- -----------------
* 4 bytes total
*/
typedef struct {
FLAC__MetaDataType type;
FLAC__bool is_last;
unsigned length; /* in bytes */
union {
FLAC__StreamMetaData_StreamInfo stream_info;
FLAC__StreamMetaData_Padding padding;
FLAC__StreamMetaData_Application application;
FLAC__StreamMetaData_SeekTable seek_table;
} data;
} FLAC__StreamMetaData;
extern const unsigned FLAC__STREAM_METADATA_IS_LAST_LEN; /* = 1 bits */
extern const unsigned FLAC__STREAM_METADATA_TYPE_LEN; /* = 7 bits */
extern const unsigned FLAC__STREAM_METADATA_LENGTH_LEN; /* = 24 bits */
/*****************************************************************************/
/*****************************************************************************
*
* Stream structures
*
*****************************************************************************/
typedef struct {
FLAC__StreamMetaData_StreamInfo stream_info;
FLAC__Frame *frames;
} FLAC__Stream;
/*****************************************************************************/
#endif
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