mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-13 19:54:39 +00:00
111 lines
3.1 KiB
C++
111 lines
3.1 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 "dsp_demodulate.hpp"
|
|
|
|
#include "complex.hpp"
|
|
#include "fxpt_atan2.hpp"
|
|
|
|
#include <hal.h>
|
|
|
|
namespace dsp {
|
|
namespace demodulate {
|
|
|
|
buffer_s16_t AM::execute(
|
|
buffer_c16_t src,
|
|
buffer_s16_t dst
|
|
) {
|
|
/* Intermediate maximum value: 46341 (when input is -32768,-32768). */
|
|
/* Normalized to maximum 32767 for int16_t representation. */
|
|
|
|
const auto src_p = src.p;
|
|
const auto src_end = &src.p[src.count];
|
|
auto dst_p = dst.p;
|
|
while(src_p < src_end) {
|
|
// const auto s = *(src_p++);
|
|
// const uint32_t r_sq = s.real() * s.real();
|
|
// const uint32_t i_sq = s.imag() * s.imag();
|
|
// const uint32_t mag_sq = r_sq + i_sq;
|
|
const uint32_t sample0 = *__SIMD32(src_p)++;
|
|
const uint32_t sample1 = *__SIMD32(src_p)++;
|
|
const uint32_t mag_sq0 = __SMUAD(sample0, sample0);
|
|
const uint32_t mag_sq1 = __SMUAD(sample1, sample1);
|
|
const int32_t mag0_int = __builtin_sqrtf(mag_sq0);
|
|
const int32_t mag0_sat = __SSAT(mag0_int, 16);
|
|
const int32_t mag1_int = __builtin_sqrtf(mag_sq1);
|
|
const int32_t mag1_sat = __SSAT(mag1_int, 16);
|
|
*__SIMD32(dst_p)++ = __PKHBT(
|
|
mag0_sat,
|
|
mag1_sat,
|
|
16
|
|
);
|
|
}
|
|
|
|
return { dst.p, src.count, src.sampling_rate };
|
|
}
|
|
/*
|
|
static inline float angle_approx_4deg0(const complex32_t t) {
|
|
const auto x = static_cast<float>(t.imag()) / static_cast<float>(t.real());
|
|
return 16384.0f * x;
|
|
}
|
|
*/
|
|
static inline float angle_approx_0deg27(const complex32_t t) {
|
|
const auto x = static_cast<float>(t.imag()) / static_cast<float>(t.real());
|
|
return x / (1.0f + 0.28086f * x * x);
|
|
}
|
|
/*
|
|
static inline float angle_precise(const complex32_t t) {
|
|
return atan2f(t.imag(), t.real());
|
|
}
|
|
*/
|
|
buffer_s16_t FM::execute(
|
|
buffer_c16_t src,
|
|
buffer_s16_t dst
|
|
) {
|
|
auto z = z_;
|
|
|
|
const auto src_p = src.p;
|
|
const auto src_end = &src.p[src.count];
|
|
auto dst_p = dst.p;
|
|
while(src_p < src_end) {
|
|
const auto s0 = *__SIMD32(src_p)++;
|
|
const auto s1 = *__SIMD32(src_p)++;
|
|
const auto t0 = multiply_conjugate_s16_s32(s0, z);
|
|
const auto t1 = multiply_conjugate_s16_s32(s1, s0);
|
|
z = s1;
|
|
const int32_t theta0_int = angle_approx_0deg27(t0) * k;
|
|
const int32_t theta0_sat = __SSAT(theta0_int, 16);
|
|
const int32_t theta1_int = angle_approx_0deg27(t1) * k;
|
|
const int32_t theta1_sat = __SSAT(theta1_int, 16);
|
|
*__SIMD32(dst_p)++ = __PKHBT(
|
|
theta0_sat,
|
|
theta1_sat,
|
|
16
|
|
);
|
|
}
|
|
z_ = z;
|
|
|
|
return { dst.p, src.count, src.sampling_rate };
|
|
}
|
|
|
|
}
|
|
}
|