mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-18 10:01:57 -05:00
6951499db3
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5721 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
40 lines
1.0 KiB
C
40 lines
1.0 KiB
C
/*
|
|
This file is part of wsprd.
|
|
|
|
File name: fano.h
|
|
|
|
Description: Header file for sequential Fano decoder.
|
|
|
|
Copyright 1994, Phil Karn, KA9Q
|
|
Minor modifications by Joe Taylor, K1JT
|
|
*/
|
|
|
|
#ifndef FANO_H
|
|
#define FANO_H
|
|
|
|
int fano(unsigned int *metric, unsigned int *cycles, unsigned int *maxnp,
|
|
unsigned char *data,unsigned char *symbols, unsigned int nbits,
|
|
int mettab[2][256],int delta,unsigned int maxcycles);
|
|
|
|
int encode(unsigned char *symbols,unsigned char *data,unsigned int nbytes);
|
|
|
|
extern unsigned char Partab[];
|
|
|
|
/* Convolutional encoder macro. Takes the encoder state, generates
|
|
* a rate 1/2 symbol pair and stores it in 'sym'. The symbol generated from
|
|
* POLY1 goes into the 2-bit of sym, and the symbol generated from POLY2
|
|
* goes into the 1-bit.
|
|
*/
|
|
#define ENCODE(sym,encstate){\
|
|
unsigned long _tmp;\
|
|
\
|
|
_tmp = (encstate) & POLY1;\
|
|
_tmp ^= _tmp >> 16;\
|
|
(sym) = Partab[(_tmp ^ (_tmp >> 8)) & 0xff] << 1;\
|
|
_tmp = (encstate) & POLY2;\
|
|
_tmp ^= _tmp >> 16;\
|
|
(sym) |= Partab[(_tmp ^ (_tmp >> 8)) & 0xff];\
|
|
}
|
|
|
|
#endif
|