ref: 7b6a889217d62ed7e28188621403cc7542fd1f7e
dir: /src/gain.c/
/* libSoX effect: gain/norm/etc. (c) 2008-9 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
*/
#define LSX_EFF_ALIAS
#include "sox_i.h"
#include <ctype.h>
#include <string.h>
typedef struct {
sox_bool do_equalise, do_balance, do_balance_no_clip, do_limiter;
sox_bool do_restore, make_headroom, do_normalise, do_scan;
double fixed_gain; /* Valid only in channel 0 */
double mult, reclaim, rms, limiter;
off_t num_samples;
sox_sample_t min, max;
FILE * tmp_file;
} priv_t;
static int create(sox_effect_t * effp, int argc, char * * argv)
{
priv_t * p = (priv_t *)effp->priv;
char const * q;
for (--argc, ++argv; argc && **argv == '-' && argv[0][1] &&
!isdigit((unsigned char)argv[0][1]) && argv[0][1] != '.'; --argc, ++argv)
for (q = &argv[0][1]; *q; ++q) switch (*q) {
case 'n': p->do_scan = p->do_normalise = sox_true; break;
case 'e': p->do_scan = p->do_equalise = sox_true; break;
case 'B': p->do_scan = p->do_balance = sox_true; break;
case 'b': p->do_scan = p->do_balance_no_clip = sox_true; break;
case 'r': p->do_scan = p->do_restore = sox_true; break;
case 'h': p->make_headroom = sox_true; break;
case 'l': p->do_limiter = sox_true; break;
default: lsx_fail("invalid option `-%c'", *q); return lsx_usage(effp);
}
if ((p->do_equalise + p->do_balance + p->do_balance_no_clip + p->do_restore)/ sox_true > 1) {
lsx_fail("only one of -e, -B, -b, -r may be given");
return SOX_EOF;
}
if (p->do_normalise && p->do_restore) {
lsx_fail("only one of -n, -r may be given");
return SOX_EOF;
}
if (p->do_limiter && p->make_headroom) {
lsx_fail("only one of -l, -h may be given");
return SOX_EOF;
}
do {NUMERIC_PARAMETER(fixed_gain, -HUGE_VAL, HUGE_VAL)} while (0);
p->fixed_gain = dB_to_linear(p->fixed_gain);
return argc? lsx_usage(effp) : SOX_SUCCESS;
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
if (effp->flow == 0) {
if (p->do_restore) {
if (!effp->in_signal.mult || *effp->in_signal.mult >= 1) {
lsx_fail("can't reclaim headroom");
return SOX_EOF;
}
p->reclaim = 1 / *effp->in_signal.mult;
}
effp->out_signal.mult = p->make_headroom? &p->fixed_gain : NULL;
if (!p->do_equalise && !p->do_balance && !p->do_balance_no_clip)
effp->flows = 1; /* essentially a conditional SOX_EFF_MCHAN */
}
p->mult = 0;
p->max = 1;
p->min = -1;
if (p->do_scan) {
p->tmp_file = lsx_tmpfile();
if (p->tmp_file == NULL) {
lsx_fail("can't create temporary file: %s", strerror(errno));
return SOX_EOF;
}
}
if (p->do_limiter)
p->limiter = (1 - 1 / p->fixed_gain) * (1. / SOX_SAMPLE_MAX);
else if (p->fixed_gain == floor(p->fixed_gain) && !p->do_scan)
effp->out_signal.precision = effp->in_signal.precision;
return SOX_SUCCESS;
}
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 len;
if (p->do_scan) {
if (fwrite(ibuf, sizeof(*ibuf), *isamp, p->tmp_file) != *isamp) {
lsx_fail("error writing temporary file: %s", strerror(errno));
return SOX_EOF;
}
if (p->do_balance && !p->do_normalise)
for (len = *isamp; len; --len, ++ibuf) {
double d = SOX_SAMPLE_TO_FLOAT_64BIT(*ibuf, effp->clips);
p->rms += sqr(d);
++p->num_samples;
}
else if (p->do_balance || p->do_balance_no_clip)
for (len = *isamp; len; --len, ++ibuf) {
double d = SOX_SAMPLE_TO_FLOAT_64BIT(*ibuf, effp->clips);
p->rms += sqr(d);
++p->num_samples;
p->max = max(p->max, *ibuf);
p->min = min(p->min, *ibuf);
}
else for (len = *isamp; len; --len, ++ibuf) {
p->max = max(p->max, *ibuf);
p->min = min(p->min, *ibuf);
}
*osamp = 0; /* samples not output until drain */
}
else {
double mult = ((priv_t *)(effp - effp->flow)->priv)->fixed_gain;
len = *isamp = *osamp = min(*isamp, *osamp);
if (!p->do_limiter) for (; len; --len, ++ibuf)
*obuf++ = SOX_ROUND_CLIP_COUNT(*ibuf * mult, effp->clips);
else for (; len; --len, ++ibuf) {
double d = *ibuf * mult;
*obuf++ = d < 0 ? 1 / (1 / d - p->limiter) - .5 :
d > 0 ? 1 / (1 / d + p->limiter) + .5 : 0;
}
}
return SOX_SUCCESS;
}
static void start_drain(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
double max = SOX_SAMPLE_MAX, max_peak = 0, max_rms = 0;
size_t i;
if (p->do_balance || p->do_balance_no_clip) {
for (i = 0; i < effp->flows; ++i) {
priv_t * q = (priv_t *)(effp - effp->flow + i)->priv;
max_rms = max(max_rms, sqrt(q->rms / q->num_samples));
rewind(q->tmp_file);
}
for (i = 0; i < effp->flows; ++i) {
priv_t * q = (priv_t *)(effp - effp->flow + i)->priv;
double this_rms = sqrt(q->rms / q->num_samples);
double this_peak = max(q->max / max, q->min / (double)SOX_SAMPLE_MIN);
q->mult = this_rms != 0? max_rms / this_rms : 1;
max_peak = max(max_peak, q->mult * this_peak);
q->mult *= p->fixed_gain;
}
if (p->do_normalise || (p->do_balance_no_clip && max_peak > 1))
for (i = 0; i < effp->flows; ++i) {
priv_t * q = (priv_t *)(effp - effp->flow + i)->priv;
q->mult /= max_peak;
}
} else if (p->do_equalise && !p->do_normalise) {
for (i = 0; i < effp->flows; ++i) {
priv_t * q = (priv_t *)(effp - effp->flow + i)->priv;
double this_peak = max(q->max / max, q->min / (double)SOX_SAMPLE_MIN);
max_peak = max(max_peak, this_peak);
q->mult = p->fixed_gain / this_peak;
rewind(q->tmp_file);
}
for (i = 0; i < effp->flows; ++i) {
priv_t * q = (priv_t *)(effp - effp->flow + i)->priv;
q->mult *= max_peak;
}
} else {
p->mult = min(max / p->max, (double)SOX_SAMPLE_MIN / p->min);
if (p->do_restore) {
if (p->reclaim > p->mult)
lsx_report("%.3gdB not reclaimed", linear_to_dB(p->reclaim / p->mult));
else p->mult = p->reclaim;
}
p->mult *= p->fixed_gain;
rewind(p->tmp_file);
}
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
size_t len;
int result = SOX_SUCCESS;
*osamp -= *osamp % effp->in_signal.channels;
if (p->do_scan) {
if (!p->mult)
start_drain(effp);
len = fread(obuf, sizeof(*obuf), *osamp, p->tmp_file);
if (len != *osamp && !feof(p->tmp_file)) {
lsx_fail("error reading temporary file: %s", strerror(errno));
result = SOX_EOF;
}
if (!p->do_limiter) for (*osamp = len; len; --len, ++obuf)
*obuf = SOX_ROUND_CLIP_COUNT(*obuf * p->mult, effp->clips);
else for (*osamp = len; len; --len) {
double d = *obuf * p->mult;
*obuf++ = d < 0 ? 1 / (1 / d - p->limiter) - .5 :
d > 0 ? 1 / (1 / d + p->limiter) + .5 : 0;
}
}
else *osamp = 0;
return result;
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
if (p->do_scan)
fclose(p->tmp_file); /* auto-deleted by lsx_tmpfile */
return SOX_SUCCESS;
}
sox_effect_handler_t const * lsx_gain_effect_fn(void)
{
static sox_effect_handler_t handler = {
"gain", NULL, SOX_EFF_GAIN,
create, start, flow, drain, stop, NULL, sizeof(priv_t)};
static char const * lines[] = {
"[-e|-b|-B|-r] [-n] [-l|-h] [gain-dB]",
"-e\t Equalise channels: peak to that with max peak;",
"-B\t Balance channels: rms to that with max rms; no clip protection",
"-b\t Balance channels: rms to that with max rms; clip protection",
"\t Note -Bn = -bn",
"-r\t Reclaim headroom (as much as possible without clipping); see -h",
"-n\t Norm file to 0dBfs(output precision); gain-dB, if present, usually <0",
"-l\t Use simple limiter",
"-h\t Apply attenuation for headroom for subsequent effects; gain-dB, if",
"\t present, is subject to reclaim by a subsequent gain -r",
"gain-dB\t Apply gain in dB",
};
static char * usage;
handler.usage = lsx_usage_lines(&usage, lines, array_length(lines));
return &handler;
}
/*------------------ emulation of the old `normalise' effect -----------------*/
static int norm_getopts(sox_effect_t * effp, int argc, char * * argv)
{
char * argv2[3];
int argc2 = 2;
argv2[0] = argv[0], --argc, ++argv;
argv2[1] = "-n";
if (argc)
argv2[argc2++] = *argv, --argc, ++argv;
return argc? lsx_usage(effp) :
lsx_gain_effect_fn()->getopts(effp, argc2, argv2);
}
sox_effect_handler_t const * lsx_norm_effect_fn(void)
{
static sox_effect_handler_t handler;
handler = *lsx_gain_effect_fn();
handler.name = "norm";
handler.usage = "[level]";
handler.getopts = norm_getopts;
return &handler;
}