void feed(buffer_c16_t src, Callback callback) {
auto src_p = src.p;
while(src_p < &src.p[src.count]) {
const uint32_t sample = *__SIMD32(src_p)++;
const uint32_t mag_sq = __SMUAD(sample, sample);
if( mag_sq > max_squared ) {
max_squared = mag_sq;
}
}
count += src.count;
const size_t samples_per_update = src.sampling_rate * update_interval;
if( count >= samples_per_update ) {
const float max_squared_f = max_squared;
const float max_db_f = complex16_mag_squared_to_dbv_norm(max_squared_f);
const int32_t max_db = max_db_f;
const ChannelStatistics statistics {
.max_db = max_db,
.count = count,
};
callback(statistics);
max_squared = 0;
count = 0;
}
}
void BasebandProcessor::update_spectrum() {
// Called from idle thread (after EVT_MASK_SPECTRUM is flagged)
if( channel_spectrum_request_update ) {
/* Decimated buffer is full. Compute spectrum. */
std::array<std::complex<float>, 256> samples_swapped;
fft_swap(channel_spectrum, samples_swapped);
channel_spectrum_request_update = false;
fft_c_preswapped(samples_swapped);
ChannelSpectrumMessage spectrum_message;
for(size_t i=0; i<spectrum_message.spectrum.db.size(); i++) {
const auto mag2 = magnitude_squared(samples_swapped[i]);
const float db = complex16_mag_squared_to_dbv_norm(mag2);
constexpr float mag_scale = 5.0f;
const unsigned int v = (db * mag_scale) + 255.0f;
spectrum_message.spectrum.db[i] = std::max(0U, std::min(255U, v));
}
/* TODO: Rename .db -> .magnitude, or something more (less!) accurate. */
spectrum_message.spectrum.db_count = spectrum_message.spectrum.db.size();
spectrum_message.spectrum.sampling_rate = channel_spectrum_sampling_rate;
spectrum_message.spectrum.channel_filter_pass_frequency = channel_filter_pass_frequency;
spectrum_message.spectrum.channel_filter_stop_frequency = channel_filter_stop_frequency;
shared_memory.application_queue.push(spectrum_message);
}
}
bool update_stats(const size_t sample_count, const size_t sampling_rate) {
count += sample_count;
const size_t samples_per_update = sampling_rate * update_interval;
if( count >= samples_per_update ) {
const float squared_sum_f = squared_sum;
const float max_squared_f = max_squared;
const float squared_avg_f = squared_sum_f / count;
statistics.rms_db = complex16_mag_squared_to_dbv_norm(squared_avg_f);
statistics.max_db = complex16_mag_squared_to_dbv_norm(max_squared_f);
statistics.count = count;
squared_sum = 0;
max_squared = 0;
count = 0;
return true;
} else {
return false;
}
}
