32 lines
1.3 KiB
C
32 lines
1.3 KiB
C
// * 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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// 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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