mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-20 23:17:42 +00:00
57 lines
1.5 KiB
C++
57 lines
1.5 KiB
C++
|
/*
|
||
|
|
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
|
||
|
|
* Copyright (C) 2018 Furrtek
|
||
|
|
*
|
||
|
|
* 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 "dsp_goertzel.hpp"
|
||
|
|
|
||
|
|
#include "complex.hpp"
|
||
|
|
#include "sine_table.hpp"
|
||
|
|
|
||
|
|
namespace dsp {
|
||
|
|
|
||
|
|
GoertzelDetector::GoertzelDetector(
|
||
|
|
const float frequency,
|
||
|
|
const uint32_t sample_rate
|
||
|
|
) {
|
||
|
|
coefficient = 2.0 * sin_f32((2.0 * pi * frequency / sample_rate) - pi / 2.0);
|
||
|
|
}
|
||
|
|
|
||
|
|
float GoertzelDetector::execute(
|
||
|
|
const buffer_s16_t& src
|
||
|
|
) {
|
||
|
|
|
||
|
|
const size_t count = src.count;
|
||
|
|
|
||
|
|
for (size_t i = 0; i < count; i++) {
|
||
|
|
s[2] = s[1];
|
||
|
|
s[1] = s[0];
|
||
|
|
s[0] = src.p[i] + coefficient * s[1] - s[2];
|
||
|
|
}
|
||
|
|
|
||
|
|
const uint32_t sq0 = s[0] * s[0];
|
||
|
|
const uint32_t sq1 = s[1] * s[1];
|
||
|
|
float magnitude = __builtin_sqrtf(sq0 + sq1 - s[0] * s[1] * coefficient);
|
||
|
|
|
||
|
|
return magnitude;
|
||
|
|
}
|
||
|
|
|
||
|
|
} /* namespace dsp */
|