/*+
−
 * 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[]));+
−