portapack-mayhem/firmware/baseband/proc_am_audio.cpp
2016-01-03 12:05:47 -08:00

80 lines
2.9 KiB
C++

/*
* 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_am_audio.hpp"
NarrowbandAMAudio::NarrowbandAMAudio() {
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;
decim_0.configure(taps_6k0_decim_0.taps, 33554432);
decim_1.configure(taps_6k0_decim_1.taps, 131072);
channel_filter.configure(taps_6k0_channel.taps, channel_filter_decimation_factor);
channel_filter_pass_f = taps_6k0_channel.pass_frequency_normalized * channel_filter_input_fs;
channel_filter_stop_f = taps_6k0_channel.stop_frequency_normalized * channel_filter_input_fs;
channel_spectrum.set_decimation_factor(std::floor((channel_filter_output_fs / 2) / ((channel_filter_pass_f + channel_filter_stop_f) / 2)));
}
void NarrowbandAMAudio::execute(const buffer_c8_t& buffer) {
std::array<complex16_t, 512> dst;
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);
// TODO: Feed channel_stats post-decimation data?
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);
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
void NarrowbandAMAudio::on_message(const Message* const message) {
if( message->id == Message::ID::UpdateSpectrum ) {
channel_spectrum.update();
}
}