/* * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc. * * This file is part of PortaPack. * * 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, 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; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #include "proc_nfm_audio.hpp" #include #include // NBFM 16K0F3E emission type ///////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=8000, stop=344000, decim=8, fout=384000 static constexpr std::array taps_16k0_decim_0 { { 1, 67, 165, 340, 599, 944, 1361, 1820, 2278, 2684, 2988, 3152, 3152, 2988, 2684, 2278, 1820, 1361, 944, 599, 340, 165, 67, 1, } }; // IFIR prototype filter: fs=384000, pass=8000, stop=40000, decim=8, fout=48000 static constexpr std::array taps_16k0_decim_1 { { -26, -125, -180, -275, -342, -359, -286, -90, 250, 733, 1337, 2011, 2688, 3289, 3740, 3982, 3982, 3740, 3289, 2688, 2011, 1337, 733, 250, -90, -286, -359, -342, -275, -180, -125, -26, } }; // Channel filter: fs=48000, pass=8000, stop=12400, decim=1, fout=48000 static constexpr std::array taps_16k0_channel { { -73, -285, -376, -8, 609, 538, -584, -1387, -148, 2173, 1959, -2146, -5267, -297, 12915, 24737, 24737, 12915, -297, -5267, -2146, 1959, 2173, -148, -1387, -584, 538, 609, -8, -376, -285, -73, } }; // NBFM 11K0F3E emission type ///////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=5500, stop=341500, decim=8, fout=384000 static constexpr std::array taps_11k0_decim_0 { { 38, 102, 220, 406, 668, 1004, 1397, 1822, 2238, 2603, 2875, 3020, 3020, 2875, 2603, 2238, 1822, 1397, 1004, 668, 406, 220, 102, 38, } }; // IFIR prototype filter: fs=384000, pass=5500, stop=42500, decim=8, fout=48000 static constexpr std::array taps_11k0_decim_1 { { -42, -87, -157, -234, -298, -318, -255, -75, 246, 713, 1306, 1976, 2656, 3265, 3724, 3971, 3971, 3724, 3265, 2656, 1976, 1306, 713, 246, -75, -255, -318, -298, -234, -157, -87, -42, } }; // Channel filter: fs=48000, pass=5500, stop=8900, decim=1, fout=48000 static constexpr std::array taps_11k0_channel { { -68, -345, -675, -867, -582, 247, 1222, 1562, 634, -1379, -3219, -3068, 310, 6510, 13331, 17795, 17795, 13331, 6510, 310, -3068, -3219, -1379, 634, 1562, 1222, 247, -582, -867, -675, -345, -68, } }; /// NBFM 8K50F3E emission type //////////////////////////////////////////// // IFIR image-reject filter: fs=3072000, pass=4250, stop=340250, decim=8, fout=384000 static constexpr std::array taps_4k25_decim_0 { { 38, 103, 222, 409, 671, 1006, 1399, 1821, 2236, 2599, 2868, 3012, 3012, 2868, 2599, 2236, 1821, 1399, 1006, 671, 409, 222, 103, 38, } }; // IFIR prototype filter: fs=384000, pass=4250, stop=43750, decim=8, fout=48000 static constexpr std::array taps_4k25_decim_1 { { -33, -74, -139, -214, -280, -306, -254, -87, 222, 682, 1274, 1951, 2644, 3268, 3741, 3996, 3996, 3741, 3268, 2644, 1951, 1274, 682, 222, -87, -254, -306, -280, -214, -139, -74, -33, } }; // Channel filter: fs=48000, pass=4250, stop=7900, decim=1, fout=48000 static constexpr std::array taps_4k25_channel { { -58, -14, 153, 484, 871, 1063, 770, -141, -1440, -2488, -2435, -614, 3035, 7771, 12226, 14927, 14927, 12226, 7771, 3035, -614, -2435, -2488, -1440, -141, 770, 1063, 871, 484, 153, -14, -58, } }; NarrowbandFMAudio::NarrowbandFMAudio() { set_mode(Mode::Deviation2K5Narrow); } void NarrowbandFMAudio::set_mode(const Mode mode) { constexpr size_t baseband_fs = 3072000; constexpr size_t decim_0_input_fs = baseband_fs; constexpr size_t decim_0_decimation_factor = 8; constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0_decimation_factor; constexpr size_t decim_1_input_fs = decim_0_output_fs; constexpr size_t decim_1_decimation_factor = 8; constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1_decimation_factor; constexpr size_t channel_filter_input_fs = decim_1_output_fs; constexpr size_t channel_filter_decimation_factor = 1; constexpr size_t channel_filter_output_fs = channel_filter_input_fs / channel_filter_decimation_factor; constexpr size_t demod_input_fs = channel_filter_output_fs; switch(mode) { default: case Mode::Deviation5K: decim_0.configure(taps_16k0_decim_0, 33554432); decim_1.configure(taps_16k0_decim_1, 131072); channel_filter.configure(taps_16k0_channel, channel_filter_decimation_factor); demod.configure(demod_input_fs, 5000); channel_filter_pass_f = 8000; channel_filter_stop_f = 12400; break; case Mode::Deviation2K5Wide: decim_0.configure(taps_11k0_decim_0, 33554432); decim_1.configure(taps_11k0_decim_1, 131072); channel_filter.configure(taps_11k0_channel, channel_filter_decimation_factor); demod.configure(demod_input_fs, 2500); channel_filter_pass_f = 5500; channel_filter_stop_f = 8900; break; case Mode::Deviation2K5Narrow: decim_0.configure(taps_4k25_decim_0, 33554432); decim_1.configure(taps_4k25_decim_1, 131072); channel_filter.configure(taps_4k25_channel, channel_filter_decimation_factor); demod.configure(demod_input_fs, 2500); channel_filter_pass_f = 4250; channel_filter_stop_f = 7900; break; } channel_spectrum.set_decimation_factor(std::floor((channel_filter_output_fs / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2))); } void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) { const buffer_c16_t dst_buffer { dst.data(), dst.size() }; const auto decim_0_out = decim_0.execute(buffer, dst_buffer); const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer); const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer); feed_channel_stats(channel_out); channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f); const buffer_s16_t work_audio_buffer { (int16_t*)dst.data(), sizeof(*dst.data()) * dst.size() }; auto audio = demod.execute(channel_out, work_audio_buffer); static uint64_t audio_present_history = 0; const auto audio_present_now = squelch.execute(audio); audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0); const bool audio_present = (audio_present_history != 0); audio_hpf.execute_in_place(audio); audio_deemph.execute_in_place(audio); if( !audio_present ) { // Zero audio buffer. for(size_t i=0; i