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att
GitHub Repository: att/ast
 Path: blob/master/src/lib/libvcodex/Vchuff/vchuff.h
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/***********************************************************************

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*                                                                      *

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*               This software is part of the ast package               *

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*          Copyright (c) 2003-2011 AT&T Intellectual Property          *

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*                      and is licensed under the                       *

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*                 Eclipse Public License, Version 1.0                  *

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*                    by AT&T Intellectual Property                     *

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*                                                                      *

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*                A copy of the License is available at                 *

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*          http://www.eclipse.org/org/documents/epl-v10.html           *

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*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *

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*                                                                      *

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*              Information and Software Systems Research               *

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*                            AT&T Research                             *

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*                           Florham Park NJ                            *

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*                                                                      *

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*                   Phong Vo <[email protected]>                    *

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*                                                                      *

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***********************************************************************/

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#ifndef _VCHUFF_H

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#define _VCHUFF_H	1

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/* Types and functions to construct a static Huffman codes.

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**

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** Written By Kiem-Phong Vo

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*/

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/* A Huffman decoding trie is stored in Vchtrie_t.node and Vchtrie_t.size.

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** size[p] > 0: a data byte has been decoded. In this case, size[p]

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**		is the number of bits that should be consumed to finish

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**		the bits corresponding to this byte. node[p] is the byte.

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** size[p] < 0: need to recurse to the next level of the trie. In this

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**		case, -size[p] is the number of bits needed to index the

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**		next level. node[p] is the base of the next level.

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** size[p] == 0: an undecipherable bit string. Data is likely corrupted.

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*/

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typedef struct _vchtrie_s

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{	short*		node;	/* data or next trie base to look up	*/

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	short*		size;	/* >0: code sizes, 0: internal nodes 	*/

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	short		ntop;	/* # of bits to index top trie level	*/

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	short		trsz;	/* allocated memory for the trie	*/

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	short		next;

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} Vchtrie_t;

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_BEGIN_EXTERNS_

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#if _BLD_vcodex && defined(__EXPORT__)

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#define extern		extern __EXPORT__

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#endif

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#if !_BLD_vcodex && defined(__IMPORT__)

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#define extern		extern __IMPORT__

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#endif

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extern Vcmethod_t*	Vchuffman;	/* Huffman compression		*/

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extern Vcmethod_t*	Vchuffgroup;	/* Huffman with grouping	*/

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extern Vcmethod_t*	Vchuffpart;	/* Huffman with partitioning	*/

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#undef	extern

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#if _BLD_vcodex && defined(__EXPORT__)

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#define extern	__EXPORT__

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#endif

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extern ssize_t		vchsize _ARG_((ssize_t, ssize_t*, ssize_t*, int*));

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extern ssize_t		vchbits _ARG_((ssize_t, ssize_t*, Vcbit_t*));

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extern Vchtrie_t*	vchbldtrie _ARG_((ssize_t, ssize_t*, Vcbit_t*));

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extern Void_t		vchdeltrie _ARG_((Vchtrie_t*));

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extern ssize_t		vchgetcode _ARG_((ssize_t, ssize_t*, ssize_t, Vcchar_t*, size_t));

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extern ssize_t		vchputcode _ARG_((ssize_t, ssize_t*, ssize_t, Vcchar_t*, size_t));

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extern int		vchcopy _ARG_((Vcodex_t*, ssize_t*, ssize_t*, ssize_t));

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#undef	extern

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_END_EXTERNS_

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#endif /*_VCHUFF_H*/

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