portapack-mayhem/firmware/baseband/dsp_demodulate.hpp
2015-07-08 08:39:24 -07:00

67 lines
1.6 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.
*/
#ifndef __DSP_DEMODULATE_H__
#define __DSP_DEMODULATE_H__
#include "dsp_types.hpp"
namespace dsp {
namespace demodulate {
class AM {
public:
buffer_s16_t execute(
buffer_c16_t src,
buffer_s16_t dst
);
};
class FM {
public:
/*
* angle: -pi to pi. output range: -32768 to 32767.
* Maximum delta-theta (output of atan2) at maximum deviation frequency:
* delta_theta_max = 2 * pi * deviation / sampling_rate
*/
constexpr FM(
const float sampling_rate,
const float deviation_hz
) : z_ { 0 },
k { static_cast<float>(32767.0f / (2.0 * pi * deviation_hz / sampling_rate)) }
{
}
buffer_s16_t execute(
buffer_c16_t src,
buffer_s16_t dst
);
private:
complex16_t::rep_type z_;
const float k;
};
} /* namespace demodulate */
} /* namespace dsp */
#endif/*__DSP_DEMODULATE_H__*/