/* * aptdec - A lightweight FOSS (NOAA) APT decoder * Copyright (C) 2019-2023 Xerbo (xerbo@protonmail.com) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #ifndef LIBAPTDEC_FILTER_H_ #define LIBAPTDEC_FILTER_H_ #include #include #ifdef _MSC_VER typedef _Fcomplex complexf_t; #define complex_build(real, imag) _FCbuild(real, imag) #define complex_multiply(a, b) _FCmulcc(a, b) #else typedef complex float complexf_t; #define complex_build(real, imag) ((real) + (imag)*I) #define complex_multiply(a, b) ((a) * (b)) #endif void design_low_pass(float *taps, float samp_rate, float cutoff, size_t ntaps); void design_hilbert(float *taps, size_t ntaps); float convolve(const float *in, const float *taps, size_t len); complexf_t hilbert_transform(const float *in, const float *taps, size_t len); float interpolating_convolve(const float *in, const float *taps, size_t len, float offset); #endif