#include <libmythtv/bitreader.h>

Public Member Functions
	BitReader (const uint8_t *buffer, uint64_t size)

	~BitReader ()=default

void	skip_bits (unsigned n)

uint32_t	show_bits (unsigned n)

uint64_t	show_bits64 (unsigned n)

bool	next_bit ()

uint32_t	get_bits (unsigned n)
	Read 0-32 bits. More...

uint64_t	get_bits64 (unsigned n)
	Read 0-64 bits. More...

int	get_ue_golomb ()
	Read an unsigned Exp-Golomb code in the range 0 to 8190 (2^13 - 2). More...

uint32_t	get_ue_golomb_long ()
	Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1. More...

int	get_ue_golomb_31 ()
	read unsigned exp golomb code, constraint to a max of 31. More...

int	get_se_golomb ()
	read signed exp golomb code. More...

int64_t	get_bits_left ()

Private Member Functions
int	get_ue_golomb (unsigned max_length)
	Valid for max_length <= 16. More...

void	refill_cache (unsigned min_bits)

Static Private Member Functions
static unsigned	clz (uint32_t v)

static constexpr uint64_t	get_upper_bits (uint64_t val, unsigned bits)

Private Attributes
const uint8_t *	m_buffer
	next memory location to read from More...

const uint8_t *const	m_bufferEnd
	past the end pointer More...

unsigned	m_bitIndex {0}
	index for next bit read from the MSB More...

uint64_t	m_cache {0}
	cache for reads. More...

unsigned	m_cacheSize {0}

Static Private Attributes
static constexpr unsigned	kCacheSizeMax {64}

static constexpr unsigned	kBitsPerRead { 8}

Detailed Description

Definition at line 38 of file bitreader.h.

Constructor & Destructor Documentation

◆ BitReader()

BitReader::BitReader	(	const uint8_t *	buffer,
		uint64_t	size
	)

inline

Definition at line 41 of file bitreader.h.

◆ ~BitReader()

BitReader::~BitReader ( )

default

Member Function Documentation

◆ skip_bits()

void BitReader::skip_bits ( unsigned n )

inline

Definition at line 48 of file bitreader.h.

Referenced by AVCParser::decode_SEI(), get_bits(), get_bits64(), get_ue_golomb(), get_ue_golomb_long(), and HEVCParser::profileTierLevel().

◆ show_bits()

uint32_t BitReader::show_bits ( unsigned n )

inline

Definition at line 66 of file bitreader.h.

Referenced by AVCParser::decode_SEI(), get_bits(), get_ue_golomb(), and get_ue_golomb_long().

◆ show_bits64()

uint64_t BitReader::show_bits64 ( unsigned n )

inline

Definition at line 75 of file bitreader.h.

Referenced by get_bits64().

◆ next_bit()

bool BitReader::next_bit ( )

inline

Definition at line 84 of file bitreader.h.

Referenced by H2645Parser::vui_parameters().

◆ get_bits()

uint32_t BitReader::get_bits ( unsigned n )

inline

Read 0-32 bits.

Definition at line 86 of file bitreader.h.

Referenced by AVCParser::decode_Header(), AVCParser::decode_PPS(), AVCParser::decode_SEI(), AVCParser::decode_SPS(), get_ue_golomb_long(), next_bit(), HEVCParser::parsePPS(), HEVCParser::parseSliceSegmentHeader(), HEVCParser::parseSPS(), HEVCParser::parseVPS(), HEVCParser::profileTierLevel(), scalingListData(), shortTermRefPicSet(), and H2645Parser::vui_parameters().

◆ get_bits64()

uint64_t BitReader::get_bits64 ( unsigned n )

inline

Read 0-64 bits.

Definition at line 93 of file bitreader.h.

◆ get_ue_golomb() [1/2]

int BitReader::get_ue_golomb ( )

inline

Read an unsigned Exp-Golomb code in the range 0 to 8190 (2^13 - 2).

Returns: the read value or a negative error code.

Definition at line 105 of file bitreader.h.

Referenced by AVCParser::decode_Header(), AVCParser::decode_PPS(), AVCParser::decode_SEI(), AVCParser::decode_SPS(), get_ue_golomb_31(), HEVCParser::parsePPS(), HEVCParser::parseSliceSegmentHeader(), HEVCParser::parseSPS(), HEVCParser::parseVPS(), scalingListData(), shortTermRefPicSet(), and H2645Parser::vui_parameters().

◆ get_ue_golomb_long()

uint32_t BitReader::get_ue_golomb_long ( )

inline

Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1.

Returns: the read value or UINT32_MAX on error.

Definition at line 115 of file bitreader.h.

Referenced by get_se_golomb(), and HEVCParser::parseVPS().

◆ get_ue_golomb_31()

int BitReader::get_ue_golomb_31 ( )

inline

read unsigned exp golomb code, constraint to a max of 31.

If the value encountered is not in 0..31, the return value is outside the range 0..30.

Definition at line 136 of file bitreader.h.

Referenced by AVCParser::decode_Header().

◆ get_se_golomb()

int BitReader::get_se_golomb ( )

inline

read signed exp golomb code.

Definition at line 144 of file bitreader.h.

Referenced by AVCParser::decode_Header(), AVCParser::decode_PPS(), AVCParser::decode_SPS(), HEVCParser::parseSliceSegmentHeader(), and scalingListData().

◆ get_bits_left()

int64_t BitReader::get_bits_left ( )

inline

Definition at line 156 of file bitreader.h.

Referenced by AVCParser::decode_SEI().

◆ get_ue_golomb() [2/2]

int BitReader::get_ue_golomb ( unsigned max_length )

inlineprivate

Valid for max_length <= 16.

Definition at line 226 of file bitreader.h.

◆ clz()

static unsigned BitReader::clz ( uint32_t v )

inlinestaticprivate

Definition at line 163 of file bitreader.h.

Referenced by get_ue_golomb(), and get_ue_golomb_long().

◆ get_upper_bits()

static constexpr uint64_t BitReader::get_upper_bits	(	uint64_t	val,
		unsigned	bits
	)

inlinestaticconstexprprivate

Definition at line 190 of file bitreader.h.

Referenced by show_bits(), and show_bits64().

◆ refill_cache()

void BitReader::refill_cache ( unsigned min_bits )

inlineprivate

Definition at line 245 of file bitreader.h.

Referenced by show_bits(), and show_bits64().

Member Data Documentation

◆ m_buffer

const uint8_t* BitReader::m_buffer

private

next memory location to read from

Definition at line 206 of file bitreader.h.

Referenced by get_bits_left(), refill_cache(), and skip_bits().

◆ m_bufferEnd

const uint8_t* const BitReader::m_bufferEnd

private

past the end pointer

Definition at line 207 of file bitreader.h.

Referenced by get_bits_left(), and refill_cache().

◆ m_bitIndex

unsigned BitReader::m_bitIndex {0}

private

index for next bit read from the MSB

Definition at line 208 of file bitreader.h.

Referenced by get_bits_left(), refill_cache(), and skip_bits().

◆ m_cache

uint64_t BitReader::m_cache {0}

private

cache for reads.

This is updated such that the next bit to read is always the Most Significant Bit.

Definition at line 216 of file bitreader.h.

Referenced by refill_cache(), show_bits(), show_bits64(), and skip_bits().

◆ m_cacheSize

unsigned BitReader::m_cacheSize {0}

private

Definition at line 217 of file bitreader.h.

Referenced by get_bits_left(), refill_cache(), show_bits(), show_bits64(), and skip_bits().

◆ kCacheSizeMax

constexpr unsigned BitReader::kCacheSizeMax {64}

staticconstexprprivate

Definition at line 219 of file bitreader.h.

Referenced by refill_cache().

◆ kBitsPerRead

constexpr unsigned BitReader::kBitsPerRead { 8}

staticconstexprprivate

Definition at line 220 of file bitreader.h.

Referenced by get_bits_left(), refill_cache(), and skip_bits().

The documentation for this class was generated from the following file:

mythtv/libs/libmythtv/bitreader.h

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ BitReader()

◆ ~BitReader()

Member Function Documentation

◆ skip_bits()

◆ show_bits()

◆ show_bits64()

◆ next_bit()

◆ get_bits()

◆ get_bits64()

◆ get_ue_golomb() [1/2]

◆ get_ue_golomb_long()

◆ get_ue_golomb_31()

◆ get_se_golomb()

◆ get_bits_left()

◆ get_ue_golomb() [2/2]

◆ clz()

◆ get_upper_bits()

◆ refill_cache()

Member Data Documentation

◆ m_buffer

◆ m_bufferEnd

◆ m_bitIndex

◆ m_cache

◆ m_cacheSize

◆ kCacheSizeMax

◆ kBitsPerRead