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- /*
- * jchuff.h
- *
- * Copyright (C) 1991-1997, Thomas G. Lane.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
- *
- * This file contains declarations for Huffman entropy encoding routines
- * that are shared between the sequential encoder (jchuff.c) and the
- * progressive encoder (jcphuff.c). No other modules need to see these.
- */
-
- /* The legal range of a DCT coefficient is
- * -1024 .. +1023 for 8-bit data;
- * -16384 .. +16383 for 12-bit data.
- * Hence the magnitude should always fit in 10 or 14 bits respectively.
- */
-
- #ifndef _jchuff_h_
- #define _jchuff_h_
-
- #if BITS_IN_JSAMPLE == 8
- #define MAX_COEF_BITS 10
- #else
- #define MAX_COEF_BITS 14
- #endif
-
- /* Derived data constructed for each Huffman table */
-
- typedef struct {
- unsigned int ehufco[256]; /* code for each symbol */
- char ehufsi[256]; /* length of code for each symbol */
- /* If no code has been allocated for a symbol S, ehufsi[S] contains 0 */
- } c_derived_tbl;
-
- /* Short forms of external names for systems with brain-damaged linkers. */
-
- #ifdef NEED_SHORT_EXTERNAL_NAMES
- #define jpeg_make_c_derived_tbl jMkCDerived
- #define jpeg_gen_optimal_table jGenOptTbl
- #endif /* NEED_SHORT_EXTERNAL_NAMES */
-
- /* Expand a Huffman table definition into the derived format */
- EXTERN(void) jpeg_make_c_derived_tbl
- JPP((j_compress_ptr cinfo, boolean isDC, int tblno,
- c_derived_tbl ** pdtbl));
-
- /* Generate an optimal table definition given the specified counts */
- EXTERN(void) jpeg_gen_optimal_table
- JPP((j_compress_ptr cinfo, JHUFF_TBL * htbl, long freq[]));
-
- #endif
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