/* * 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. */#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[]));