Huffman bit stream decoding

Description

API for operations related to Huffman bit stream decoding.

Used in engines:

• SCUMM

Classes
class	Common::Huffman< BITSTREAM >

Functions
uint32	Common::REVERSEBITS (uint32 x)
static Huffman	Common::Huffman< BITSTREAM >::fromFrequencies (std::initializer_list< uint32 > freqs)
static Huffman	Common::Huffman< BITSTREAM >::fromFrequencies (uint32 freqCount, const uint32 *freq, const uint32 *symbols)
	Common::Huffman< BITSTREAM >::Huffman (uint8 maxLength, uint32 codeCount, const uint32 *codes, const uint8 *lengths, const uint32 *symbols=nullptr)
uint32	Common::Huffman< BITSTREAM >::getSymbol (BITSTREAM &bits) const

Function Documentation

fromFrequencies() [1/2]

template<class BITSTREAM >

Huffman< BITSTREAM > Common::Huffman< BITSTREAM >::fromFrequencies ( std::initializer_list< uint32 >  freqs )

static

Construct Huffman decoder from the symbol frequencies using canonical huffman algorithm. Symbols added for each non-zero frequency in the list

Parameters

freqs

Frequencies,

fromFrequencies() [2/2]

template<class BITSTREAM >

Huffman< BITSTREAM > Common::Huffman< BITSTREAM >::fromFrequencies ( uint32  freqCount, const uint32 *  freq, const uint32 *  symbols  )

static

Construct Huffman decoder from the symbol frequencies using canonical huffman algorithm.

Parameters

freqCount	Number of frequencies.
freq	Frequencies.
symbols	Symbols.

Huffman()

template<class BITSTREAM >

Common::Huffman< BITSTREAM >::Huffman	(	uint8	maxLength,
		uint32	codeCount,
		const uint32 *	codes,
		const uint8 *	lengths,
		const uint32 *	symbols = nullptr
	)

Construct a Huffman decoder.

Parameters

maxLength	Maximal code length. If 0, it is searched for.
codeCount	Number of codes.
codes	The actual codes.
lengths	Lengths of the individual codes.
symbols	The symbols. If 0, assume they are identical to the code indices.

getSymbol()

template<class BITSTREAM >

uint32 Common::Huffman< BITSTREAM >::getSymbol

(

BITSTREAM &

bits

)

const

Return the next symbol in the bit stream.