diff --git a/decode.cc b/decode.cc index dd9509b..43ff1c2 100644 --- a/decode.cc +++ b/decode.cc @@ -152,7 +152,7 @@ void base37_decoder(char *str, long long int val, int len) str[i] = " 0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"[val%37]; } -template +template struct Decoder { typedef DSP::Const Const; @@ -163,19 +163,17 @@ struct Decoder static const int ldpc_bits = 64800; static const int bch_bits = ldpc_bits - 21600; static const int data_bits = bch_bits - 12 * 16; - static const int code_cols = 432; static const int cons_cnt = ldpc_bits / Mod::BITS; - static const int code_rows = cons_cnt / code_cols; - static const int code_off = -216; - static const int mls0_off = -126; + static const int rows_max = cons_cnt / cols_min; static const int mls0_len = 127; + static const int mls0_off = - mls0_len + 1; static const int mls0_poly = 0b10001001; static const int mls1_len = 255; - static const int mls1_off = -127; + static const int mls1_off = - mls1_len / 2; static const int mls1_poly = 0b100101011; static const int mls3_poly = 0b10001000000001011; static const int mls4_poly = 0b10111010010000001; - static const int buffer_len = (code_rows + 8) * (symbol_len + guard_len); + static const int buffer_len = (rows_max + 8) * (symbol_len + guard_len); static const int search_pos = buffer_len - 4 * (symbol_len + guard_len); DSP::ReadPCM *pcm; DSP::FastFourierTransform fwd; @@ -264,7 +262,7 @@ struct Decoder for (int k = 0; k < Mod::BITS; ++k) bint[Mod::BITS*i+k] = code[cons_cnt*k+i]; } - Decoder(uint8_t *out, DSP::ReadPCM *pcm, int skip_count) : + Decoder(uint8_t *out, DSP::ReadPCM *pcm, int skip_count, int code_cols) : pcm(pcm), resample(rate, (rate * 19) / 40, 2), correlator(mls0_seq()), crc0(0xA8F4) { CODE::BoseChaudhuriHocquenghemGenerator<255, 71>::matrix(genmat, true, { @@ -338,6 +336,9 @@ struct Decoder call_sign[9] = 0; std::cerr << "call sign: " << call_sign << std::endl; + int code_rows = cons_cnt / code_cols; + int code_off = - code_cols / 2; + int dis = displacement(buf+symbol_pos-(code_rows+1)*(symbol_len+guard_len), buf+symbol_pos+2*(symbol_len+guard_len)); sfo_rad = (dis * Const::TwoPi()) / ((code_rows+3)*(symbol_len+guard_len)); std::cerr << "coarse sfo: " << 1000000 * sfo_rad / Const::TwoPi() << " ppm" << std::endl; @@ -461,21 +462,21 @@ int main(int argc, char **argv) if (argc > 3) skip_count = std::atoi(argv[3]); - const int code_len = 64800 / 8; + const int code_len = 64800 / 8, code_cols = 432, cols_min = 360; uint8_t *output_data = new uint8_t[code_len]; switch (input_file.rate()) { case 8000: - delete new Decoder(output_data, &input_file, skip_count); + delete new Decoder(output_data, &input_file, skip_count, code_cols); break; case 16000: - delete new Decoder(output_data, &input_file, skip_count); + delete new Decoder(output_data, &input_file, skip_count, code_cols); break; case 44100: - delete new Decoder(output_data, &input_file, skip_count); + delete new Decoder(output_data, &input_file, skip_count, code_cols); break; case 48000: - delete new Decoder(output_data, &input_file, skip_count); + delete new Decoder(output_data, &input_file, skip_count, code_cols); break; default: std::cerr << "Unsupported sample rate." << std::endl; diff --git a/encode.cc b/encode.cc index 4b165c4..97f1ab1 100644 --- a/encode.cc +++ b/encode.cc @@ -31,9 +31,7 @@ struct Encoder static const int ldpc_bits = 64800; static const int bch_bits = ldpc_bits - 21600; static const int data_bits = bch_bits - 12 * 16; - static const int code_cols = 432; static const int cons_cnt = ldpc_bits / Mod::BITS; - static const int code_rows = cons_cnt / code_cols; static const int mls0_len = 127; static const int mls0_poly = 0b10001001; static const int mls1_len = 255; @@ -55,6 +53,8 @@ struct Encoder cmplx temp[symbol_len]; cmplx guard[guard_len]; cmplx papr_min, papr_max; + int code_cols; + int code_rows; int code_off; int mls0_off; int mls1_off; @@ -180,7 +180,7 @@ struct Encoder for (int k = 0; k < Mod::BITS; ++k) bint[Mod::BITS*i+k] = code[cons_cnt*k+i]; } - Encoder(DSP::WritePCM *pcm, uint8_t *inp, int freq_off, uint64_t call_sign) : + Encoder(DSP::WritePCM *pcm, uint8_t *inp, int freq_off, uint64_t call_sign, int code_cols) : pcm(pcm), crc0(0xA8F4), bchenc0({ 0b100011101, 0b101110111, 0b111110011, 0b101101001, 0b110111101, 0b111100111, 0b100101011, 0b111010111, @@ -191,11 +191,13 @@ struct Encoder 0b10000000000101101, 0b10000000101110011, 0b10000111110111101, 0b10101101001010101, 0b10001111100101111, 0b11111011110110101, 0b11010111101100101, 0b10111001101100111, 0b10000111010100001, - 0b10111010110100111, 0b10011101000101101, 0b10001101011100011}) + 0b10111010110100111, 0b10011101000101101, 0b10001101011100011}), + code_cols(code_cols), code_rows(cons_cnt / code_cols) { - code_off = (freq_off * symbol_len) / rate - code_cols / 2; - mls0_off = code_off + 90; - mls1_off = code_off + 89; + int offset = (freq_off * symbol_len) / rate; + code_off = offset - code_cols / 2; + mls0_off = offset - mls0_len + 1; + mls1_off = offset - mls1_len / 2; papr_min = cmplx(1000, 1000), papr_max = cmplx(-1000, -1000); pilot_block(); schmidl_cox(); @@ -283,7 +285,7 @@ int main(int argc, char **argv) std::cerr << "Couldn't open file \"" << input_name << "\" for reading." << std::endl; return 1; } - const int code_len = 64800 / 8; + const int code_len = 64800 / 8, code_cols = 432; const int data_len = code_len - (12 * 16 + 21600) / 8; uint8_t *input_data = new uint8_t[code_len]; for (int i = 0; i < data_len; ++i) @@ -293,16 +295,16 @@ int main(int argc, char **argv) output_file.silence(output_rate); switch (output_rate) { case 8000: - delete new Encoder(&output_file, input_data, freq_off, call_sign); + delete new Encoder(&output_file, input_data, freq_off, call_sign, code_cols); break; case 16000: - delete new Encoder(&output_file, input_data, freq_off, call_sign); + delete new Encoder(&output_file, input_data, freq_off, call_sign, code_cols); break; case 44100: - delete new Encoder(&output_file, input_data, freq_off, call_sign); + delete new Encoder(&output_file, input_data, freq_off, call_sign, code_cols); break; case 48000: - delete new Encoder(&output_file, input_data, freq_off, call_sign); + delete new Encoder(&output_file, input_data, freq_off, call_sign, code_cols); break; default: std::cerr << "Unsupported sample rate." << std::endl;