Clementine-audio-player-Mac.../src/analyzers/fht.cpp

198 lines
4.6 KiB
C++

/* This file is part of Clementine.
Copyright 2004, Melchior FRANZ <mfranz@kde.org>
Copyright 2010, 2014, John Maguire <john.maguire@gmail.com>
Copyright 2014, Krzysztof Sobiecki <sobkas@gmail.com>
Clementine 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 3 of the License, or
(at your option) any later version.
Clementine 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 Clementine. If not, see <http://www.gnu.org/licenses/>.
*/
/* Original Author: Melchior FRANZ <mfranz@kde.org> 2004
*/
#include "fht.h"
#include <cmath>
FHT::FHT(int n) : num_((n < 3) ? 0 : 1 << n), exp2_((n < 3) ? -1 : n) {
if (n > 3) {
buf_vector_.resize(num_);
tab_vector_.resize(num_ * 2);
makeCasTable();
}
}
FHT::~FHT() {}
int FHT::sizeExp() const { return exp2_; }
int FHT::size() const { return num_; }
float* FHT::buf_() { return buf_vector_.data(); }
float* FHT::tab_() { return tab_vector_.data(); }
int* FHT::log_() { return log_vector_.data(); }
void FHT::makeCasTable(void) {
float* costab = tab_();
float* sintab = tab_() + num_ / 2 + 1;
for (int ul = 0; ul < num_; ul++) {
float d = M_PI * ul / (num_ / 2);
*costab = *sintab = cos(d);
costab += 2;
sintab += 2;
if (sintab > tab_() + num_ * 2) sintab = tab_() + 1;
}
}
void FHT::scale(float* p, float d) {
for (int i = 0; i < (num_ / 2); i++) *p++ *= d;
}
void FHT::ewma(float* d, float* s, float w) {
for (int i = 0; i < (num_ / 2); i++, d++, s++) *d = *d * w + *s * (1 - w);
}
void FHT::logSpectrum(float* out, float* p) {
int n = num_ / 2, i, j, k, *r;
if (log_vector_.size() < n) {
log_vector_.resize(n);
float f = n / log10(static_cast<double>(n));
for (i = 0, r = log_(); i < n; i++, r++) {
j = static_cast<int>(rint(log10(i + 1.0) * f));
*r = j >= n ? n - 1 : j;
}
}
semiLogSpectrum(p);
*out++ = *p = *p / 100;
for (k = i = 1, r = log_(); i < n; i++) {
j = *r++;
if (i == j) {
*out++ = p[i];
} else {
float base = p[k - 1];
float step = (p[j] - base) / (j - (k - 1));
for (float corr = 0; k <= j; k++, corr += step) *out++ = base + corr;
}
}
}
void FHT::semiLogSpectrum(float* p) {
power2(p);
for (int i = 0; i < (num_ / 2); i++, p++) {
float e = 10.0 * log10(sqrt(*p / 2));
*p = e < 0 ? 0 : e;
}
}
void FHT::spectrum(float* p) {
power2(p);
for (int i = 0; i < (num_ / 2); i++, p++)
*p = static_cast<float>(sqrt(*p / 2));
}
void FHT::power(float* p) {
power2(p);
for (int i = 0; i < (num_ / 2); i++) *p++ /= 2;
}
void FHT::power2(float* p) {
_transform(p, num_, 0);
*p = static_cast<float>(2 * pow(*p, 2));
p++;
float* q = p + num_ - 2;
for (int i = 1; i < (num_ / 2); i++) {
*p = static_cast<float>(pow(*p, 2) + pow(*q, 2));
p++;
q--;
}
}
void FHT::transform(float* p) {
if (num_ == 8)
transform8(p);
else
_transform(p, num_, 0);
}
void FHT::transform8(float* p) {
float a, b, c, d, e, f, g, h, b_f2, d_h2;
float a_c_eg, a_ce_g, ac_e_g, aceg, b_df_h, bdfh;
a = *p++, b = *p++, c = *p++, d = *p++;
e = *p++, f = *p++, g = *p++, h = *p;
b_f2 = (b - f) * M_SQRT2;
d_h2 = (d - h) * M_SQRT2;
a_c_eg = a - c - e + g;
a_ce_g = a - c + e - g;
ac_e_g = a + c - e - g;
aceg = a + c + e + g;
b_df_h = b - d + f - h;
bdfh = b + d + f + h;
*p = a_c_eg - d_h2;
*--p = a_ce_g - b_df_h;
*--p = ac_e_g - b_f2;
*--p = aceg - bdfh;
*--p = a_c_eg + d_h2;
*--p = a_ce_g + b_df_h;
*--p = ac_e_g + b_f2;
*--p = aceg + bdfh;
}
void FHT::_transform(float* p, int n, int k) {
if (n == 8) {
transform8(p + k);
return;
}
int i, j, ndiv2 = n / 2;
float a, *t1, *t2, *t3, *t4, *ptab, *pp;
for (i = 0, t1 = buf_(), t2 = buf_() + ndiv2, pp = &p[k]; i < ndiv2; i++)
*t1++ = *pp++, *t2++ = *pp++;
std::copy(buf_(), buf_() + n, p + k);
_transform(p, ndiv2, k);
_transform(p, ndiv2, k + ndiv2);
j = num_ / ndiv2 - 1;
t1 = buf_();
t2 = t1 + ndiv2;
t3 = p + k + ndiv2;
ptab = tab_();
pp = p + k;
a = *ptab++ * *t3++;
a += *ptab * *pp;
ptab += j;
*t1++ = *pp + a;
*t2++ = *pp++ - a;
for (i = 1, t4 = p + k + n; i < ndiv2; i++, ptab += j) {
a = *ptab++ * *t3++;
a += *ptab * *--t4;
*t1++ = *pp + a;
*t2++ = *pp++ - a;
}
std::copy(buf_(), buf_() + n, p + k);
}