Compression

Functions
int	wc_Compress (byte *out, word32 outSz, const byte *in, word32 inSz, word32 flags)
	This function compresses the given input data using Huffman coding and stores the output in out. Note that the output buffer should still be larger than the input buffer because there exists a certain input for which there will be no compression possible, which will still require a lookup table. It is recommended that one allocate srcSz + 0.1% + 12 for the output buffer. More...
int	wc_DeCompress (byte *out, word32 outSz, const byte *in, word32 inSz)
	This function decompresses the given compressed data using Huffman coding and stores the output in out. More...

Detailed Description

Function Documentation

wc_Compress()

int wc_Compress	(	byte *	out,
		word32	outSz,
		const byte *	in,
		word32	inSz,
		word32	flags
	)

This function compresses the given input data using Huffman coding and stores the output in out. Note that the output buffer should still be larger than the input buffer because there exists a certain input for which there will be no compression possible, which will still require a lookup table. It is recommended that one allocate srcSz + 0.1% + 12 for the output buffer.

Returns

On successfully compressing the input data, returns the number of bytes stored in the output buffer

COMPRESS_INIT_E Returned if there is an error initializing the stream for compression

COMPRESS_E Returned if an error occurs during compression

Parameters

out	pointer to the output buffer in which to store the compressed data
outSz	size available in the output buffer for storage
in	pointer to the buffer containing the message to compress
inSz	size of the input message to compress
flags	flags to control how compression operates. Use 0 for normal decompression

Example

byte message[] = { // initialize text to compress };
byte compressed[(sizeof(message) + sizeof(message) * .001 + 12 )];
// Recommends at least srcSz + .1% + 12
 
if( wc_Compress(compressed, sizeof(compressed), message, sizeof(message),
0) != 0){
    // error compressing data
}

See also

wc_DeCompress

wc_DeCompress()

int wc_DeCompress	(	byte *	out,
		word32	outSz,
		const byte *	in,
		word32	inSz
	)

This function decompresses the given compressed data using Huffman coding and stores the output in out.

Returns

Success On successfully decompressing the input data, returns the number of bytes stored in the output buffer

COMPRESS_INIT_E: Returned if there is an error initializing the stream for compression

COMPRESS_E: Returned if an error occurs during compression

Parameters

out	pointer to the output buffer in which to store the decompressed data
outSz	size available in the output buffer for storage
in	pointer to the buffer containing the message to decompress
inSz	size of the input message to decompress

Example

byte compressed[] = { // initialize compressed message };
byte decompressed[MAX_MESSAGE_SIZE];
 
if( wc_DeCompress(decompressed, sizeof(decompressed),
compressed, sizeof(compressed)) != 0 ) {
    // error decompressing data
}

See also

wc_Compress