2005-08-26 04:48:05 +00:00
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/*
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* jchuff.h
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*
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* Copyright (C) 1991-1995, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This file contains declarations for Huffman entropy encoding routines
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* that are shared between the sequential encoder (jchuff.c) and the
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* progressive encoder (jcphuff.c). No other modules need to see these.
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*/
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/* Derived data constructed for each Huffman table */
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typedef struct {
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unsigned int ehufco[256]; /* code for each symbol */
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char ehufsi[256]; /* length of code for each symbol */
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/* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
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} c_derived_tbl;
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/* Short forms of external names for systems with brain-damaged linkers. */
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#ifdef NEED_SHORT_EXTERNAL_NAMES
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#define jpeg_make_c_derived_tbl jMkCDerived
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#define jpeg_gen_optimal_table jGenOptTbl
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#endif /* NEED_SHORT_EXTERNAL_NAMES */
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/* Expand a Huffman table definition into the derived format */
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EXTERN void jpeg_make_c_derived_tbl JPP((j_compress_ptr cinfo,
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JHUFF_TBL * htbl, c_derived_tbl ** pdtbl));
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/* Generate an optimal table definition given the specified counts */
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EXTERN void jpeg_gen_optimal_table JPP((j_compress_ptr cinfo,
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JHUFF_TBL * htbl, long freq[]));
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