ref: 4eb9609a1a04a1f72ec472e7362860cb110c5b1a
dir: /src/loudness.c/
/* Effect: loudness filter Copyright (c) 2008 robs@users.sourceforge.net
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) 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 Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "sox_i.h"
#include "fft4g.h"
#define FIFO_SIZE_T int
#include "fifo.h"
#include <string.h>
typedef struct {
int dft_length, num_taps;
double * coefs;
} filter_t;
typedef struct {
double delta, start;
int n;
size_t samples_in, samples_out;
fifo_t input_fifo, output_fifo;
filter_t filter, * filter_ptr;
} priv_t;
static int create(sox_effect_t * effp, int argc, char **argv)
{
priv_t * p = (priv_t *)effp->priv;
p->filter_ptr = &p->filter;
p->delta = -10;
p->start = 65;
p->n = 1023;
do { /* break-able block */
NUMERIC_PARAMETER(delta,-50 , 15)
NUMERIC_PARAMETER(start, 50 , 75)
NUMERIC_PARAMETER(n ,127 ,2047)
} while (0);
p->n = 2 * p->n + 1;
return argc? lsx_usage(effp) : SOX_SUCCESS;
}
static double * make_filter(int n, double start, double delta, double rate)
{
static const struct {double f, af, lu, tf;} iso226_table[] = {
{ 20,0.532,-31.6,78.5},{ 25,0.506,-27.2,68.7},{ 31.5,0.480,-23.0,59.5},
{ 40,0.455,-19.1,51.1},{ 50,0.432,-15.9,44.0},{ 63,0.409,-13.0,37.5},
{ 80,0.387,-10.3,31.5},{ 100,0.367, -8.1,26.5},{ 125,0.349, -6.2,22.1},
{ 160,0.330, -4.5,17.9},{ 200,0.315, -3.1,14.4},{ 250,0.301, -2.0,11.4},
{ 315,0.288, -1.1, 8.6},{ 400,0.276, -0.4, 6.2},{ 500,0.267, 0.0, 4.4},
{ 630,0.259, 0.3, 3.0},{ 800,0.253, 0.5, 2.2},{ 1000,0.250, 0.0, 2.4},
{ 1250,0.246, -2.7, 3.5},{ 1600,0.244, -4.1, 1.7},{ 2000,0.243, -1.0,-1.3},
{ 2500,0.243, 1.7,-4.2},{ 3150,0.243, 2.5,-6.0},{ 4000,0.242, 1.2,-5.4},
{ 5000,0.242, -2.1,-1.5},{ 6300,0.245, -7.1, 6.0},{ 8000,0.254,-11.2,12.6},
{10000,0.271,-10.7,13.9},{12500,0.301, -3.1,12.3},
};
#define LEN (array_length(iso226_table) + 2)
#define SPL(phon, t) (10 / t.af * log10(4.47e-3 * (pow(10., .025 * (phon)) - \
1.15) + pow(.4 * pow(10., (t.tf + t.lu) / 10 - 9), t.af)) - t.lu + 94)
double fs[LEN], spl[LEN], d[LEN], * work, * h;
int i, work_len;
fs[0] = log(1.);
spl[0] = delta * .2;
for (i = 0; i < (int)LEN - 2; ++i) {
spl[i + 1] = SPL(start + delta, iso226_table[i]) -
SPL(start , iso226_table[i]);
fs[i + 1] = log(iso226_table[i].f);
}
fs[i + 1] = log(100000.);
spl[i + 1] = spl[0];
lsx_prepare_spline3(fs, spl, (int)LEN, HUGE_VAL, HUGE_VAL, d);
for (work_len = 8192; work_len < rate / 2; work_len <<= 1);
work = lsx_calloc(work_len, sizeof(*work));
h = lsx_calloc(n, sizeof(*h));
for (i = 1; i <= work_len / 2; ++i) {
double f = rate * i / work_len;
double spl1 = f < 1? spl[0] : lsx_spline3(fs, spl, d, (int)LEN, log(f));
work[i < work_len / 2 ? 2 * i : 1] = dB_to_linear(spl1);
}
lsx_safe_rdft(work_len, -1, work);
for (i = 0; i < n; ++i)
h[i] = work[(work_len - n / 2 + i) % work_len] * 2. / work_len;
lsx_apply_kaiser(h, n, lsx_kaiser_beta(40 + 2./3 * fabs(delta)));
free(work);
return h;
#undef SPL
#undef LEN
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *) effp->priv;
int i, half = p->n / 2, dft_length = lsx_set_dft_length(p->n);
double * h;
if (p->delta == 0)
return SOX_EFF_NULL;
if (!p->filter_ptr->num_taps) {
h = make_filter(p->n, p->start, p->delta, effp->in_signal.rate);
p->filter_ptr->coefs = lsx_calloc(dft_length, sizeof(*p->filter_ptr->coefs));
for (i = 0; i < p->n; ++i)
p->filter_ptr->coefs[(i + dft_length - p->n + 1) & (dft_length - 1)]
= h[i] / dft_length * 2;
free(h);
p->filter_ptr->num_taps = p->n;
p->filter_ptr->dft_length = dft_length;
lsx_safe_rdft(dft_length, 1, p->filter_ptr->coefs);
}
fifo_create(&p->input_fifo, (int)sizeof(double));
memset(fifo_reserve(&p->input_fifo, half), 0, sizeof(double) * half);
fifo_create(&p->output_fifo, (int)sizeof(double));
return SOX_SUCCESS;
}
static void filter(priv_t * p)
{
int i, num_in = max(0, fifo_occupancy(&p->input_fifo));
filter_t const * f = p->filter_ptr;
int const overlap = f->num_taps - 1;
double * output;
while (num_in >= f->dft_length) {
double const * input = fifo_read_ptr(&p->input_fifo);
fifo_read(&p->input_fifo, f->dft_length - overlap, NULL);
num_in -= f->dft_length - overlap;
output = fifo_reserve(&p->output_fifo, f->dft_length);
fifo_trim_by(&p->output_fifo, overlap);
memcpy(output, input, f->dft_length * sizeof(*output));
lsx_rdft(f->dft_length, 1, output, lsx_fft_br, lsx_fft_sc);
output[0] *= f->coefs[0];
output[1] *= f->coefs[1];
for (i = 2; i < f->dft_length; i += 2) {
double tmp = output[i];
output[i ] = f->coefs[i ] * tmp - f->coefs[i+1] * output[i+1];
output[i+1] = f->coefs[i+1] * tmp + f->coefs[i ] * output[i+1];
}
lsx_rdft(f->dft_length, -1, output, lsx_fft_br, lsx_fft_sc);
}
}
static int flow(sox_effect_t * effp, const sox_sample_t * ibuf,
sox_sample_t * obuf, size_t * isamp, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
size_t i, odone = min(*osamp, (size_t)fifo_occupancy(&p->output_fifo));
double const * s = fifo_read(&p->output_fifo, (int)odone, NULL);
for (i = 0; i < odone; ++i)
*obuf++ = SOX_FLOAT_64BIT_TO_SAMPLE(*s++, effp->clips);
p->samples_out += odone;
if (*isamp && odone < *osamp) {
double * t = fifo_write(&p->input_fifo, (int)*isamp, NULL);
p->samples_in += (int)*isamp;
for (i = *isamp; i; --i)
*t++ = SOX_SAMPLE_TO_FLOAT_64BIT(*ibuf++, effp->clips);
filter(p);
}
else *isamp = 0;
*osamp = odone;
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
static size_t isamp = 0;
size_t samples_out = p->samples_in;
size_t remaining = samples_out - p->samples_out;
double * buff = lsx_calloc(1024, sizeof(*buff));
if ((int)remaining > 0) {
while ((size_t)fifo_occupancy(&p->output_fifo) < remaining) {
fifo_write(&p->input_fifo, 1024, buff);
p->samples_in += 1024;
filter(p);
}
fifo_trim_to(&p->output_fifo, (int)remaining);
p->samples_in = 0;
}
free(buff);
return flow(effp, 0, obuf, &isamp, osamp);
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *) effp->priv;
fifo_delete(&p->input_fifo);
fifo_delete(&p->output_fifo);
free(p->filter_ptr->coefs);
memset(p->filter_ptr, 0, sizeof(*p->filter_ptr));
return SOX_SUCCESS;
}
sox_effect_handler_t const * sox_loudness_effect_fn(void)
{
static sox_effect_handler_t handler = {
"loudness", "[gain [ref]]", 0,
create, start, flow, drain, stop, NULL, sizeof(priv_t)
};
return &handler;
}