kopia lustrzana https://github.com/Guenael/rtlsdr-wsprd
44 wiersze
1.1 KiB
C
44 wiersze
1.1 KiB
C
/*
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This file is part of wsprd.
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File name: fano.h
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Description: Header file for sequential Fano decoder.
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Copyright 1994, Phil Karn, KA9Q
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Minor modifications by Joe Taylor, K1JT
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*/
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#pragma once
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int fano(unsigned int *metric,
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unsigned int *cycles,
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unsigned int *maxnp,
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unsigned char *data,
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unsigned char *symbols,
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unsigned int nbits,
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int mettab[2][256],
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int delta,
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unsigned int maxcycles);
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int encode(unsigned char *symbols,
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unsigned char *data,
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unsigned int nbytes);
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extern unsigned char Partab[];
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/* Convolutional encoder macro. Takes the encoder state, generates
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* a rate 1/2 symbol pair and stores it in 'sym'. The symbol generated from
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* POLY1 goes into the 2-bit of sym, and the symbol generated from POLY2
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* goes into the 1-bit.
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*/
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#define ENCODE(sym, encstate) {\
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unsigned long _tmp;\
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_tmp = (encstate) & POLY1;\
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_tmp ^= _tmp >> 16;\
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(sym) = Partab[(_tmp ^ (_tmp >> 8)) & 0xff] << 1;\
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_tmp = (encstate) & POLY2;\
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_tmp ^= _tmp >> 16;\
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(sym) |= Partab[(_tmp ^ (_tmp >> 8)) & 0xff];\
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}
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