Detailed Description

Huffman code for data compression.

Public Member Functions
unsigned long long	compute (unsigned int *occurrences, unsigned int size)
	Compute code from a raw buffer of occurrences and return resulting byte size.

int	storeTree (unsigned char *buffer) const
	Stores the huffman tree in the buffer and returns the number of bytes used.

bool	loadTree (const unsigned char *buffer)
	Loads the huffman tree from the buffer.

void	clear ()
	Clear everything.

unsigned char	bits (unsigned short symbol) const
	Return the number of bits for a given symbol.

unsigned long long	code (unsigned short symbol) const
	Return the code for a given symbol.

template<typename T>
int	encode (const T bufIn, unsigned int size, unsigned char bufOut, unsigned int bufOutSize, unsigned int &bitPos)
	Encode data, sizes of both input and output buffer are given, along with the latter's bit position.

template<typename T>
int	decode (const unsigned char bufIn, int size, T bufOut) const
	Decode data.

void	debugTree (std::ostream &osObject, bool leavesOnly=false, bool charSymbols=false) const
	Output a tabular representation of the huffman tree for debugging purposes.

unsigned long long	numBytesForBits (const unsigned long long bitSize) const
	Computes the number of bytes that are needed to store n bits.

Member Function Documentation

◆ storeTree()

int storeTree ( unsigned char * buffer ) const

Stores the huffman tree in the buffer and returns the number of bytes used.

Returns 0 in case of too small buffer

◆ loadTree()

bool loadTree ( const unsigned char * buffer )

Loads the huffman tree from the buffer.

Returns true if successful

◆ bits()

unsigned char bits ( unsigned short symbol ) const

Return the number of bits for a given symbol.

This method is written for speed, no checking whatsoever is performed.

◆ encode()

template<typename T>

int encode	(	const T *	bufIn,
		unsigned int	size,
		unsigned char *	bufOut,
		unsigned int	bufOutSize,
		unsigned int &	bitPos )

Encode data, sizes of both input and output buffer are given, along with the latter's bit position.

The bit position will be updated by this method. The number of encoded bytes is returned, if it is smaller than the specified size, the encoded data did not fit into the output buffer, hence this method has to be called again with an increased output buffer size.

◆ decode()

template<typename T>

int decode	(	const unsigned char *	bufIn,
		int	size,
		T *	bufOut ) const

Decode data.

Both input and output buffers need to contain sufficient memory to accomodate the size of the data.

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

ImFusion/Base/Huffman.h