mirror of
https://github.com/ddnet/ddnet.git
synced 2024-11-14 03:58:18 +00:00
90 lines
2.1 KiB
C++
90 lines
2.1 KiB
C++
#ifndef ENGINE_SHARED_HUFFMAN_H
|
|
#define ENGINE_SHARED_HUFFMAN_H
|
|
|
|
|
|
|
|
class CHuffman
|
|
{
|
|
enum
|
|
{
|
|
HUFFMAN_EOF_SYMBOL = 256,
|
|
|
|
HUFFMAN_MAX_SYMBOLS=HUFFMAN_EOF_SYMBOL+1,
|
|
HUFFMAN_MAX_NODES=HUFFMAN_MAX_SYMBOLS*2-1,
|
|
|
|
HUFFMAN_LUTBITS = 10,
|
|
HUFFMAN_LUTSIZE = (1<<HUFFMAN_LUTBITS),
|
|
HUFFMAN_LUTMASK = (HUFFMAN_LUTSIZE-1)
|
|
};
|
|
|
|
struct CNode
|
|
{
|
|
// symbol
|
|
unsigned m_Bits;
|
|
unsigned m_NumBits;
|
|
|
|
// don't use pointers for this. shorts are smaller so we can fit more data into the cache
|
|
unsigned short m_aLeafs[2];
|
|
|
|
// what the symbol represents
|
|
unsigned char m_Symbol;
|
|
};
|
|
|
|
CNode m_aNodes[HUFFMAN_MAX_NODES];
|
|
CNode *m_apDecodeLut[HUFFMAN_LUTSIZE];
|
|
CNode *m_pStartNode;
|
|
int m_NumNodes;
|
|
|
|
void Setbits_r(CNode *pNode, int Bits, unsigned Depth);
|
|
void ConstructTree(const unsigned *pFrequencies);
|
|
|
|
public:
|
|
/*
|
|
Function: huffman_init
|
|
Inits the compressor/decompressor.
|
|
|
|
Parameters:
|
|
huff - Pointer to the state to init
|
|
frequencies - A pointer to an array of 256 entries of the frequencies of the bytes
|
|
|
|
Remarks:
|
|
- Does no allocation what so ever.
|
|
- You don't have to call any cleanup functions when you are done with it
|
|
*/
|
|
void Init(const unsigned *pFrequencies);
|
|
|
|
/*
|
|
Function: huffman_compress
|
|
Compresses a buffer and outputs a compressed buffer.
|
|
|
|
Parameters:
|
|
huff - Pointer to the huffman state
|
|
input - Buffer to compress
|
|
input_size - Size of the buffer to compress
|
|
output - Buffer to put the compressed data into
|
|
output_size - Size of the output buffer
|
|
|
|
Returns:
|
|
Returns the size of the compressed data. Negative value on failure.
|
|
*/
|
|
int Compress(const void *pInput, int InputSize, void *pOutput, int OutputSize);
|
|
|
|
/*
|
|
Function: huffman_decompress
|
|
Decompresses a buffer
|
|
|
|
Parameters:
|
|
huff - Pointer to the huffman state
|
|
input - Buffer to decompress
|
|
input_size - Size of the buffer to decompress
|
|
output - Buffer to put the uncompressed data into
|
|
output_size - Size of the output buffer
|
|
|
|
Returns:
|
|
Returns the size of the uncompressed data. Negative value on failure.
|
|
*/
|
|
int Decompress(const void *pInput, int InputSize, void *pOutput, int OutputSize);
|
|
|
|
};
|
|
#endif // __HUFFMAN_HEADER__
|