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GLAST / LAT > DAQ and FSW > FSW > Doxygen Index> LDT / V0-5-0 > encdec / linux-gcc

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HDD.h File Reference

Interface to the routines to decode a distribution of symbols previously encoded using HDE_encodeSS. More...

Typedefs
typedef struct _HDD	HDD
Functions
void *	HDD_construct (HDD *hde, unsigned int nhuff)
	Constructs (initializes) the specified HDD structure.
unsigned int	HDD_sizeof (unsigned int nhuff)
	Returns the size, in bytes, for a handle to hold a Huffman distribution of huffman_bins.
unsigned int	HDD_decodeS (HDD *hdd, const unsigned int *src, unsigned int pos, unsigned int max_pos, short *syms, unsigned int nsyms)
	Unpacks the distribution encoded with HDD_encodeSS.
unsigned int	HDD_tableDecode (HDD *hdd, const unsigned int *src, unsigned int pos, unsigned int max_pos)
	Unpacks the table encoded with HDE_tableEncode.
unsigned int	HDD_symbolsDecodeS (HDD *hdd, const unsigned int *src, unsigned int pos, unsigned int max_pos, short *syms, unsigned int nsyms)
	Unpacks the distribution encoded with HDD_symbolsEncodeS.

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Detailed Description

Interface to the routines to decode a distribution of symbols previously encoded using HDE_encodeSS.

Author:

JJRussell - russell@slac.stanford.edu

   CVS $Id: HDD.h,v 1.2 2010/08/06 18:58:49 saxton Exp $

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Function Documentation

void HDD_construct	(	HDD *	hdd,
		unsigned int	nhuff
	)

Constructs (initializes) the specified HDD structure.

Returns:

The next address after this structure.

Parameters:

	hdd	The HDD control structure to construct
	nhuff	The maximum number of Huffman encoding bins that this control structure is meant to support.

The size of this structure should be acquired by a call to HDD_sizeof. The parameter huffman_nbins must be the same in the call to HDD_sizeof and HDD_construct.

unsigned int HDD_decodeS	(	HDD *	hdd,
		const unsigned int *	src,
		unsigned int	pos,
		unsigned int	max_pos,
		short *	syms,
		unsigned int	nsyms
	)

Unpacks the distribution encoded with HDD_encodeSS.

Returns:

The next bit position to read.

Parameters:

	hdd	The decode handle
	src	The source stream
	pos	The current bit read position
	max_pos	The maximum bit position, i.e. do not read past this point
	syms	The array to receive the decoded symbols
	nsyms	The number of symbols to decode

unsigned int HDD_sizeof

(

unsigned int

nhuff

)

Returns the size, in bytes, for a handle to hold a Huffman distribution of huffman_bins.

Parameters:

nhuff

The maximum number of Huffman codes

For the most part, this only provides a working area. On host-based workstations with expandable stacks, this memory would go on the stack, except for the fact that it is variable length.

unsigned int HDD_symbolsDecodeS	(	HDD *	hdd,
		const unsigned int *	src,
		unsigned int	pos,
		unsigned int	max_pos,
		short *	syms,
		unsigned int	nsyms
	)

Unpacks the distribution encoded with HDD_symbolsEncodeS.

Returns:

The next bit position to read.

Parameters:

	hdd	The decode handle
	src	The source stream
	pos	The current bit read position
	max_pos	The maximum bit position, i.e. do not read past this point
	syms	The array to receive the decoded symbols
	nsyms	The number of symbols to decode

unsigned int HDD_tableDecode	(	HDD *	hdd,
		const unsigned int *	src,
		unsigned int	pos,
		unsigned int	max_pos
	)

Unpacks the table encoded with HDE_tableEncode.

Returns:

The next bit position to read.

Parameters:

	hdd	The decode handle
	src	The source stream
	pos	The current bit read position
	max_pos	The maximum bit position, i.e. do not read past this point

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