ref: 38ee09740775bfbd25280edd4c41cbe30d383333
dir: /src/dither.c/
/* Effect: dither/noise-shape Copyright (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
*/
#ifdef NDEBUG /* Enable assert always. */
#undef NDEBUG /* Must undef above assert.h or other that might include it. */
#endif
#include "sox_i.h"
#include "getopt.h"
#include <assert.h>
#undef RANQD1
#define RANQD1 ranqd1(p->ranqd1)
typedef enum { /* Collection of various filters from the net */
Shape_none, Shape_lipshitz, Shape_f_weighted, Shape_modified_e_weighted,
Shape_improved_e_weighted, Shape_gesemann, Shape_shibata, Shape_low_shibata, Shape_high_shibata
} filter_name_t;
static lsx_enum_item const filter_names[] = {
LSX_ENUM_ITEM(Shape_,none)
LSX_ENUM_ITEM(Shape_,lipshitz)
{"f-weighted", Shape_f_weighted},
{"modified-e-weighted", Shape_modified_e_weighted},
{"improved-e-weighted", Shape_improved_e_weighted},
LSX_ENUM_ITEM(Shape_,gesemann)
LSX_ENUM_ITEM(Shape_,shibata)
{"low-shibata", Shape_low_shibata},
{"high-shibata", Shape_high_shibata},
{0, 0}};
typedef struct {
sox_rate_t rate;
enum {fir, iir} type;
size_t len;
int gain_cB; /* Chosen so clips are few if any, but not guaranteed none. */
double const * coefs;
filter_name_t name;
} filter_t;
static double const lip44[] = {2.033, -2.165, 1.959, -1.590, .6149};
static double const fwe44[] = {
2.412, -3.370, 3.937, -4.174, 3.353, -2.205, 1.281, -.569, .0847};
static double const mew44[] = {
1.662, -1.263, .4827, -.2913, .1268, -.1124, .03252, -.01265, -.03524};
static double const iew44[] = {
2.847, -4.685, 6.214, -7.184, 6.639, -5.032, 3.263, -1.632, .4191};
static double const ges44[] = {
2.2061, -.4706, -.2534, -.6214, 1.0587, .0676, -.6054, -.2738};
static double const ges48[] = {
2.2374, -.7339, -.1251, -.6033, .903, .0116, -.5853, -.2571};
static double const shi48[] = {
2.8720729351043701172, -5.0413231849670410156, 6.2442994117736816406,
-5.8483986854553222656, 3.7067542076110839844, -1.0495119094848632812,
-1.1830236911773681641, 2.1126792430877685547, -1.9094531536102294922,
0.99913084506988525391, -0.17090806365013122559, -0.32615602016448974609,
0.39127644896507263184, -0.26876461505889892578, 0.097676105797290802002,
-0.023473845794796943665,
};
static double const shi44[] = {
2.6773197650909423828, -4.8308925628662109375, 6.570110321044921875,
-7.4572014808654785156, 6.7263274192810058594, -4.8481650352478027344,
2.0412089824676513672, 0.7006359100341796875, -2.9537565708160400391,
4.0800385475158691406, -4.1845216751098632812, 3.3311812877655029297,
-2.1179926395416259766, 0.879302978515625, -0.031759146600961685181,
-0.42382788658142089844, 0.47882103919982910156, -0.35490813851356506348,
0.17496839165687561035, -0.060908168554306030273,
};
static double const shi38[] = {
1.6335992813110351562, -2.2615492343902587891, 2.4077029228210449219,
-2.6341717243194580078, 2.1440362930297851562, -1.8153258562088012695,
1.0816224813461303711, -0.70302653312683105469, 0.15991993248462677002,
0.041549518704414367676, -0.29416576027870178223, 0.2518316805362701416,
-0.27766478061676025391, 0.15785403549671173096, -0.10165894031524658203,
0.016833892092108726501,
};
static double const shl48[] = {
2.3925774097442626953, -3.4350297451019287109, 3.1853709220886230469,
-1.8117271661758422852, -0.20124770700931549072, 1.4759907722473144531,
-1.7210904359817504883, 0.97746700048446655273, -0.13790138065814971924,
-0.38185903429985046387, 0.27421241998672485352, 0.066584214568138122559,
-0.35223302245140075684, 0.37672343850135803223, -0.23964276909828186035,
0.068674825131893157959,
};
static double const shl44[] = {
2.0833916664123535156, -3.0418450832366943359, 3.2047898769378662109,
-2.7571926116943359375, 1.4978630542755126953, -0.3427594602108001709,
-0.71733748912811279297, 1.0737057924270629883, -1.0225815773010253906,
0.56649994850158691406, -0.20968692004680633545, -0.065378531813621520996,
0.10322438180446624756, -0.067442022264003753662, -0.00495197344571352005,
};
static double const shh44[] = {
3.0259189605712890625, -6.0268716812133789062, 9.195003509521484375,
-11.824929237365722656, 12.767142295837402344, -11.917946815490722656,
9.1739168167114257812, -5.3712320327758789062, 1.1393624544143676758,
2.4484779834747314453, -4.9719839096069335938, 6.0392003059387207031,
-5.9359521865844726562, 4.903278350830078125, -3.5527443885803222656,
2.1909697055816650391, -1.1672389507293701172, 0.4903914332389831543,
-0.16519790887832641602, 0.023217858746647834778,
};
static const filter_t filters[] = {
{44100, fir, 5, 210, lip44, Shape_lipshitz},
{46000, fir, 9, 276, fwe44, Shape_f_weighted},
{46000, fir, 9, 160, mew44, Shape_modified_e_weighted},
{46000, fir, 9, 321, iew44, Shape_improved_e_weighted},
{48000, iir, 4, 220, ges48, Shape_gesemann},
{44100, iir, 4, 230, ges44, Shape_gesemann},
{48000, fir, 16, 301, shi48, Shape_shibata},
{44100, fir, 20, 333, shi44, Shape_shibata},
{37800, fir, 16, 240, shi38, Shape_shibata},
{48000, fir, 16, 250, shl48, Shape_low_shibata},
{44100, fir, 15, 250, shl44, Shape_low_shibata},
{44100, fir, 20, 383, shh44, Shape_high_shibata},
{ 0, fir, 0, 0, NULL, Shape_none},
};
#define MAX_N 20
typedef struct {
filter_name_t filter_name;
sox_bool auto_detect, alt_tpdf;
double dummy;
double previous_errors[MAX_N * 2];
double previous_outputs[MAX_N * 2];
size_t pos, prec, num_output;
int32_t history, ranqd1, r;
double const * coefs;
sox_bool dither_off;
int (*flow)(sox_effect_t *, const sox_sample_t *, sox_sample_t *, size_t *, size_t *);
} priv_t;
#define CONVOLVE _ _ _ _
#define NAME flow_iir_4
#define IIR
#define N 4
#include "dither.h"
#undef IIR
#define CONVOLVE _ _ _ _ _
#define NAME flow_fir_5
#define N 5
#include "dither.h"
#define CONVOLVE _ _ _ _ _ _ _ _ _
#define NAME flow_fir_9
#define N 9
#include "dither.h"
#define CONVOLVE _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
#define NAME flow_fir_15
#define N 15
#include "dither.h"
#define CONVOLVE _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
#define NAME flow_fir_16
#define N 16
#include "dither.h"
#define CONVOLVE _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
#define NAME flow_fir_20
#define N 20
#include "dither.h"
static int flow_no_shape(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 = *isamp = *osamp = min(*isamp, *osamp);
while (len--) {
if (!p->auto_detect || (p->history = ((p->history << 1) + !!(*ibuf & (-1u >> p->prec))))) {
int32_t r = RANQD1 >> p->prec;
double d = ((double)*ibuf++ + r + (p->alt_tpdf? -p->r : (RANQD1 >> p->prec))) / (1 << (32 - p->prec));
int i = d < 0? d - .5 : d + .5;
p->r = r;
if (i <= (-1 << (p->prec-1)))
++effp->clips, *obuf = SOX_SAMPLE_MIN;
else if (i > (int)SOX_INT_MAX(p->prec))
++effp->clips, *obuf = SOX_INT_MAX(p->prec) << (32 - p->prec);
else *obuf = i << (32 - p->prec);
++obuf;
if (p->dither_off)
lsx_debug("flow %u: on @ %u", (unsigned)effp->flow, (unsigned)p->num_output);
p->dither_off = sox_false;
}
else {
*obuf++ = *ibuf++;
if (!p->dither_off)
lsx_debug("flow %u: off @ %u", (unsigned)effp->flow, (unsigned)p->num_output);
p->dither_off = sox_true;
}
++p->num_output;
}
return SOX_SUCCESS;
}
static int getopts(sox_effect_t * effp, int argc, char * * argv)
{
priv_t * p = (priv_t *)effp->priv;
int c;
while ((c = getopt(argc, argv, "+aSsf:""rt")) != -1) switch (c) {
case 'a': p->auto_detect = sox_true; break;
case 'S': p->alt_tpdf = sox_true; break;
case 'r': case 't': break; /* No longer in use */
case 's': p->filter_name = Shape_shibata; break;
case 'f':
p->filter_name = lsx_enum_option(c, filter_names);
if (p->filter_name == INT_MAX)
return SOX_EOF;
break;
default: lsx_fail("invalid option `-%c'", optopt); return lsx_usage(effp);
}
argc -= optind, argv += optind;
do {NUMERIC_PARAMETER(dummy, 0.5, 1)} while (0); /* No longer in use */
return argc? lsx_usage(effp) : SOX_SUCCESS;
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
double mult = 1; /* Amount the noise shaping multiplies up the TPDF (+/-1) */
p->prec = effp->out_signal.precision;
if (effp->in_signal.precision <= p->prec || p->prec > 24)
return SOX_EFF_NULL; /* Dithering not needed at this resolution */
effp->out_signal.precision = effp->in_signal.precision;
p->flow = flow_no_shape;
if (p->filter_name) {
filter_t const * f;
for (f = filters; f->len && (f->name != p->filter_name || fabs(effp->in_signal.rate - f->rate) / f->rate > .05); ++f); /* 5% leeway on frequency */
if (!f->len) {
p->alt_tpdf |= effp->in_signal.rate >= 22050;
if (!effp->flow)
lsx_warn("no `%s' filter is available for rate %g; using %s TPDF",
lsx_find_enum_value(p->filter_name, filter_names)->text,
effp->in_signal.rate, p->alt_tpdf? "sloped" : "plain");
}
else {
assert(f->len <= MAX_N);
if (f->type == fir) switch(f->len) {
case 5: p->flow = flow_fir_5 ; break;
case 9: p->flow = flow_fir_9 ; break;
case 15: p->flow = flow_fir_15; break;
case 16: p->flow = flow_fir_16; break;
case 20: p->flow = flow_fir_20; break;
default: assert(sox_false);
} else switch(f->len) {
case 4: p->flow = flow_iir_4 ; break;
default: assert(sox_false);
}
p->coefs = f->coefs;
mult = dB_to_linear(f->gain_cB / 10);
}
}
p->ranqd1 = ranqd1(sox_globals.ranqd1) + effp->flow;
if (effp->in_signal.mult) /* (Takes account of ostart mult (sox.c). */
*effp->in_signal.mult *= (SOX_SAMPLE_MAX - (1 << (31 - p->prec)) *
(2 * mult + 1)) / (SOX_SAMPLE_MAX - (1 << (31 - p->prec)));
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;
return p->flow(effp, ibuf, obuf, isamp, osamp);
}
sox_effect_handler_t const * lsx_dither_effect_fn(void)
{
static sox_effect_handler_t handler = {
"dither", "[-a] [-S|-s|-f filter]"
"\n (none) Use TPDF"
"\n -a Automatically turn on & off dithering as needed (use with caution!)"
"\n -S Use sloped TPDF (without noise shaping)"
"\n -s Shape noise (with shibata filter)"
"\n -f name Set shaping filter to one of: lipshitz, f-weighted,"
"\n modified-e-weighted, improved-e-weighted, gesemann,"
"\n shibata, low-shibata, high-shibata.",
SOX_EFF_PREC, getopts, start, flow, 0, 0, 0, sizeof(priv_t)
};
return &handler;
}