mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-15 04:28:10 +00:00
193 lines
7.5 KiB
C++
193 lines
7.5 KiB
C++
/*
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* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
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*
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* This file is part of PortaPack.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#include "proc_nfm_audio.hpp"
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#include <cstdint>
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#include <cstddef>
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// NBFM 16K0F3E emission type /////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=8000, stop=344000, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_16k0_decim_0 { {
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1, 67, 165, 340, 599, 944, 1361, 1820,
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2278, 2684, 2988, 3152, 3152, 2988, 2684, 2278,
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1820, 1361, 944, 599, 340, 165, 67, 1,
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} };
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// IFIR prototype filter: fs=384000, pass=8000, stop=40000, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_16k0_decim_1 { {
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-26, -125, -180, -275, -342, -359, -286, -90,
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250, 733, 1337, 2011, 2688, 3289, 3740, 3982,
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3982, 3740, 3289, 2688, 2011, 1337, 733, 250,
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-90, -286, -359, -342, -275, -180, -125, -26,
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} };
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// Channel filter: fs=48000, pass=8000, stop=12400, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_16k0_channel { {
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-73, -285, -376, -8, 609, 538, -584, -1387,
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-148, 2173, 1959, -2146, -5267, -297, 12915, 24737,
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24737, 12915, -297, -5267, -2146, 1959, 2173, -148,
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-1387, -584, 538, 609, -8, -376, -285, -73,
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} };
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// NBFM 11K0F3E emission type /////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=5500, stop=341500, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_11k0_decim_0 { {
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38, 102, 220, 406, 668, 1004, 1397, 1822,
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2238, 2603, 2875, 3020, 3020, 2875, 2603, 2238,
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1822, 1397, 1004, 668, 406, 220, 102, 38,
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} };
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// IFIR prototype filter: fs=384000, pass=5500, stop=42500, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_11k0_decim_1 { {
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-42, -87, -157, -234, -298, -318, -255, -75,
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246, 713, 1306, 1976, 2656, 3265, 3724, 3971,
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3971, 3724, 3265, 2656, 1976, 1306, 713, 246,
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-75, -255, -318, -298, -234, -157, -87, -42,
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} };
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// Channel filter: fs=48000, pass=5500, stop=8900, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_11k0_channel { {
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-68, -345, -675, -867, -582, 247, 1222, 1562,
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634, -1379, -3219, -3068, 310, 6510, 13331, 17795,
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17795, 13331, 6510, 310, -3068, -3219, -1379, 634,
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1562, 1222, 247, -582, -867, -675, -345, -68,
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} };
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/// NBFM 8K50F3E emission type ////////////////////////////////////////////
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// IFIR image-reject filter: fs=3072000, pass=4250, stop=340250, decim=8, fout=384000
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static constexpr std::array<int16_t, 24> taps_4k25_decim_0 { {
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38, 103, 222, 409, 671, 1006, 1399, 1821,
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2236, 2599, 2868, 3012, 3012, 2868, 2599, 2236,
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1821, 1399, 1006, 671, 409, 222, 103, 38,
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} };
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// IFIR prototype filter: fs=384000, pass=4250, stop=43750, decim=8, fout=48000
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static constexpr std::array<int16_t, 32> taps_4k25_decim_1 { {
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-33, -74, -139, -214, -280, -306, -254, -87,
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222, 682, 1274, 1951, 2644, 3268, 3741, 3996,
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3996, 3741, 3268, 2644, 1951, 1274, 682, 222,
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-87, -254, -306, -280, -214, -139, -74, -33,
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} };
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// Channel filter: fs=48000, pass=4250, stop=7900, decim=1, fout=48000
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static constexpr std::array<int16_t, 32> taps_4k25_channel { {
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-58, -14, 153, 484, 871, 1063, 770, -141,
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-1440, -2488, -2435, -614, 3035, 7771, 12226, 14927,
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14927, 12226, 7771, 3035, -614, -2435, -2488, -1440,
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-141, 770, 1063, 871, 484, 153, -14, -58,
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} };
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NarrowbandFMAudio::NarrowbandFMAudio() {
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set_mode(Mode::Deviation2K5Narrow);
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}
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void NarrowbandFMAudio::set_mode(const Mode mode) {
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constexpr size_t baseband_fs = 3072000;
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constexpr size_t decim_0_input_fs = baseband_fs;
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constexpr size_t decim_0_decimation_factor = 8;
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constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0_decimation_factor;
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constexpr size_t decim_1_input_fs = decim_0_output_fs;
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constexpr size_t decim_1_decimation_factor = 8;
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constexpr size_t decim_1_output_fs = decim_1_input_fs / decim_1_decimation_factor;
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constexpr size_t channel_filter_input_fs = decim_1_output_fs;
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constexpr size_t channel_filter_decimation_factor = 1;
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constexpr size_t channel_filter_output_fs = channel_filter_input_fs / channel_filter_decimation_factor;
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constexpr size_t demod_input_fs = channel_filter_output_fs;
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switch(mode) {
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default:
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case Mode::Deviation5K:
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decim_0.configure(taps_16k0_decim_0, 33554432);
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decim_1.configure(taps_16k0_decim_1, 131072);
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channel_filter.configure(taps_16k0_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 5000);
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channel_filter_pass_f = 8000;
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channel_filter_stop_f = 12400;
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break;
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case Mode::Deviation2K5Wide:
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decim_0.configure(taps_11k0_decim_0, 33554432);
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decim_1.configure(taps_11k0_decim_1, 131072);
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channel_filter.configure(taps_11k0_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 2500);
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channel_filter_pass_f = 5500;
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channel_filter_stop_f = 8900;
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break;
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case Mode::Deviation2K5Narrow:
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decim_0.configure(taps_4k25_decim_0, 33554432);
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decim_1.configure(taps_4k25_decim_1, 131072);
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channel_filter.configure(taps_4k25_channel, channel_filter_decimation_factor);
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demod.configure(demod_input_fs, 2500);
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channel_filter_pass_f = 4250;
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channel_filter_stop_f = 7900;
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break;
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}
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channel_spectrum.set_decimation_factor(std::floor((channel_filter_output_fs / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2)));
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}
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void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
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const buffer_c16_t dst_buffer {
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dst.data(),
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dst.size()
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};
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const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
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const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
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const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
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feed_channel_stats(channel_out);
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channel_spectrum.feed(channel_out, channel_filter_pass_f, channel_filter_stop_f);
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const buffer_s16_t work_audio_buffer {
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(int16_t*)dst.data(),
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sizeof(*dst.data()) * dst.size()
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};
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auto audio = demod.execute(channel_out, work_audio_buffer);
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static uint64_t audio_present_history = 0;
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const auto audio_present_now = squelch.execute(audio);
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audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
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const bool audio_present = (audio_present_history != 0);
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audio_hpf.execute_in_place(audio);
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audio_deemph.execute_in_place(audio);
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if( !audio_present ) {
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// Zero audio buffer.
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for(size_t i=0; i<audio.count; i++) {
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audio.p[i] = 0;
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}
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}
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fill_audio_buffer(audio);
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}
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