ft8_lib/ft8/decode.h

#pragma once

#include <stdint.h>

namespace ft8 {

struct Candidate {
    int16_t      score;
    int16_t      time_offset;
    int16_t      freq_offset;
    uint8_t      time_sub;
    uint8_t      freq_sub;
};


// Localize top N candidates in frequency and time according to their sync strength (looking at Costas symbols)
// We treat and organize the candidate list as a min-heap (empty initially).
int find_sync(const uint8_t *power, int num_blocks, int num_bins, const uint8_t *sync_map, int num_candidates, Candidate *heap);


// Compute log likelihood log(p(1) / p(0)) of 174 message bits 
// for later use in soft-decision LDPC decoding
void extract_likelihood(const uint8_t *power, int num_bins, const Candidate & cand, const uint8_t *code_map, float *log174);

}