www.pudn.com > ampegsrc.zip > HUFFMAN.H

/********************************************************************** 
Copyright (c) 1991 MPEG/audio software simulation group, All Rights Reserved 
huffman.h 
**********************************************************************/ 
/********************************************************************** 
 * MPEG/audio coding/decoding software, work in progress              * 
 *   NOT for public distribution until verified and approved by the   * 
 *   MPEG/audio committee.  For further information, please contact   * 
 *   Davis Pan, 708-538-5671, e-mail: pan@ukraine.corp.mot.com        * 
 *                                                                    * 
 * VERSION 4.3                                                        * 
 *   changes made since last update:                                  * 
 *   date   programmers                comment                        * 
 *  27.2.92 F.O.Witte (ITT Intermetall)				      * 
 *  8/24/93 M. Iwadare          Changed for 1 pass decoding.          * 
 *  7/14/94 J. Koller		useless 'typedef' before huffcodetab  * 
 *				removed				      * 
 *********************************************************************/	 
  
#define HUFFBITS unsigned long int 
#define HTN	34 
#define MXOFF	250 
  
struct huffcodetab { 
  char tablename[3];	/*string, containing table_description	*/ 
  unsigned int xlen; 	/*max. x-index+			      	*/  
  unsigned int ylen;	/*max. y-index+				*/ 
  unsigned int linbits; /*number of linbits			*/ 
  unsigned int linmax;	/*max number to be stored in linbits	*/ 
  int ref;		/*a positive value indicates a reference*/ 
  HUFFBITS *table;	/*pointer to array[xlen][ylen]		*/ 
  unsigned char *hlen;	/*pointer to array[xlen][ylen]		*/ 
  unsigned char(*val)[2];/*decoder tree				*/  
  unsigned int treelen;	/*length of decoder tree		*/ 
}; 
 
extern struct huffcodetab ht[HTN];/* global memory block		*/ 
				/* array of all huffcodtable headers	*/ 
				/* 0..31 Huffman code table 0..31	*/ 
				/* 32,33 count1-tables			*/ 
#ifdef PROTO_ARGS 
 
extern int read_huffcodetab(FILE *);  
extern int read_decoder_table(FILE *); 
  
extern void huffman_coder(unsigned int, unsigned int, 
			  struct huffcodetab *, Bit_stream_struc *); 
			   
extern int huffman_decoder(struct huffcodetab *, 
			   /* unsigned */ int *, /* unsigned */ int*, int*, int*); 
 
#else 
 
extern int read_huffcodetab();  
extern int read_decoder_table();  
extern void huffman_coder(); 
extern int huffman_decoder(); 
 
#endif