portapack-mayhem/firmware/baseband/proc_nfm_audio.cpp

102 lines
3.5 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_nfm_audio.hpp"
#include "dsp_iir_config.hpp"
#include "audio_output.hpp"
#include <cstdint>
#include <cstddef>
void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
if( !configured ) {
return;
}
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);
auto audio = demod.execute(channel_out, work_audio_buffer);
audio_output.write(audio);
}
void NarrowbandFMAudio::on_message(const Message* const message) {
switch(message->id) {
case Message::ID::UpdateSpectrum:
channel_spectrum.update();
break;
case Message::ID::NBFMConfigure:
configure(*reinterpret_cast<const NBFMConfigureMessage*>(message));
break;
case Message::ID::SpectrumStreamingConfig:
streaming_config(*reinterpret_cast<const SpectrumStreamingConfigMessage*>(message));
break;
default:
break;
}
}
void NarrowbandFMAudio::configure(const NBFMConfigureMessage& message) {
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;
decim_0.configure(message.decim_0_filter.taps, 33554432);
decim_1.configure(message.decim_1_filter.taps, 131072);
channel_filter.configure(message.channel_filter.taps, channel_filter_decimation_factor);
demod.configure(demod_input_fs, message.deviation);
channel_filter_pass_f = message.channel_filter.pass_frequency_normalized * channel_filter_input_fs;
channel_filter_stop_f = message.channel_filter.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)));
audio_output.configure(audio_hpf_300hz_config, audio_deemph_300_6_config, 6144);
configured = true;
}
void NarrowbandFMAudio::streaming_config(const SpectrumStreamingConfigMessage& message) {
if( message.mode == SpectrumStreamingConfigMessage::Mode::Running ) {
channel_spectrum.start();
} else {
channel_spectrum.stop();
}
}