gstreamer/gst/legacyresample/functable.c
Sebastian Dröge e4e3b44e04 Rename audioresample files and types to legacyresample
Finish the move/rename of audioresample to legacyresample
to prevent any confusion.
2009-01-23 12:47:19 +01:00

254 lines
4.7 KiB
C

/* Resampling library
* Copyright (C) <2001> David A. Schleef <ds@schleef.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "functable.h"
#include "debug.h"
void
functable_func_sinc (double *fx, double *dfx, double x, void *closure)
{
if (x == 0) {
*fx = 1;
*dfx = 0;
return;
}
*fx = sin (x) / x;
*dfx = (cos (x) - sin (x) / x) / x;
}
void
functable_func_boxcar (double *fx, double *dfx, double x, void *closure)
{
double width = *(double *) closure;
if (x < width && x > -width) {
*fx = 1;
} else {
*fx = 0;
}
*dfx = 0;
}
void
functable_func_hanning (double *fx, double *dfx, double x, void *closure)
{
double width = *(double *) closure;
if (x < width && x > -width) {
x /= width;
*fx = (1 - x * x) * (1 - x * x);
*dfx = -2 * 2 * x / width * (1 - x * x);
} else {
*fx = 0;
*dfx = 0;
}
}
Functable *
functable_new (void)
{
Functable *ft;
ft = malloc (sizeof (Functable));
memset (ft, 0, sizeof (Functable));
return ft;
}
void
functable_free (Functable * ft)
{
free (ft);
}
void
functable_set_length (Functable * t, int length)
{
t->length = length;
}
void
functable_set_offset (Functable * t, double offset)
{
t->offset = offset;
}
void
functable_set_multiplier (Functable * t, double multiplier)
{
t->multiplier = multiplier;
}
void
functable_calculate (Functable * t, FunctableFunc func, void *closure)
{
int i;
double x;
if (t->fx)
free (t->fx);
if (t->dfx)
free (t->dfx);
t->fx = malloc (sizeof (double) * (t->length + 1));
t->dfx = malloc (sizeof (double) * (t->length + 1));
t->inv_multiplier = 1.0 / t->multiplier;
for (i = 0; i < t->length + 1; i++) {
x = t->offset + t->multiplier * i;
func (&t->fx[i], &t->dfx[i], x, closure);
}
}
void
functable_calculate_multiply (Functable * t, FunctableFunc func, void *closure)
{
int i;
double x;
for (i = 0; i < t->length + 1; i++) {
double afx, adfx, bfx, bdfx;
afx = t->fx[i];
adfx = t->dfx[i];
x = t->offset + t->multiplier * i;
func (&bfx, &bdfx, x, closure);
t->fx[i] = afx * bfx;
t->dfx[i] = afx * bdfx + adfx * bfx;
}
}
double
functable_evaluate (Functable * t, double x)
{
int i;
double f0, f1, w0, w1;
double x2, x3;
double w;
if (x < t->offset || x > (t->offset + t->length * t->multiplier)) {
RESAMPLE_DEBUG ("x out of range %g", x);
}
x -= t->offset;
x *= t->inv_multiplier;
i = floor (x);
x -= i;
x2 = x * x;
x3 = x2 * x;
f1 = 3 * x2 - 2 * x3;
f0 = 1 - f1;
w0 = (x - 2 * x2 + x3) * t->multiplier;
w1 = (-x2 + x3) * t->multiplier;
w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1;
/*w = t->fx[i] * (1-x) + t->fx[i+1] * x; */
return w;
}
double
functable_fir (Functable * t, double x, int n, double *data, int len)
{
int i, j;
double f0, f1, w0, w1;
double x2, x3;
double w;
double sum;
x -= t->offset;
x /= t->multiplier;
i = floor (x);
x -= i;
x2 = x * x;
x3 = x2 * x;
f1 = 3 * x2 - 2 * x3;
f0 = 1 - f1;
w0 = (x - 2 * x2 + x3) * t->multiplier;
w1 = (-x2 + x3) * t->multiplier;
sum = 0;
for (j = 0; j < len; j++) {
w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1;
sum += data[j * 2] * w;
i += n;
}
return sum;
}
void
functable_fir2 (Functable * t, double *r0, double *r1, double x,
int n, double *data, int len)
{
int i, j;
double f0, f1, w0, w1;
double x2, x3;
double w;
double sum0, sum1;
double floor_x;
x -= t->offset;
x *= t->inv_multiplier;
floor_x = floor (x);
i = floor_x;
x -= floor_x;
x2 = x * x;
x3 = x2 * x;
f1 = 3 * x2 - 2 * x3;
f0 = 1 - f1;
w0 = (x - 2 * x2 + x3) * t->multiplier;
w1 = (-x2 + x3) * t->multiplier;
sum0 = 0;
sum1 = 0;
for (j = 0; j < len; j++) {
w = t->fx[i] * f0 + t->fx[i + 1] * f1 + t->dfx[i] * w0 + t->dfx[i + 1] * w1;
sum0 += data[j * 2] * w;
sum1 += data[j * 2 + 1] * w;
i += n;
}
*r0 = sum0;
*r1 = sum1;
}