sox_ng/src/dither.h
Martin Guy ec5b66c174 Don't say "p->" in GETOPT_NUMERIC errors
and revert previous ad-hoc hacks to obtain the same effect
2025-10-05 10:58:29 +02:00

79 lines
2.9 KiB
C

/* Copyright (c) 2009 Rob Sykes (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 IIR
#define _ output += p->coefs[j] * p->previous_errors[p->pos + j] \
- p->coefs[N + j] * p->previous_outputs[p->pos + j], ++j;
#else
#define _ d -= p->coefs[j] * p->previous_errors[p->pos + j], ++j;
#endif
static int NAME(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 & (((unsigned)-1) >> p->precision));
if (p->history && p->dither_off) {
p->dither_off = sox_false;
lsx_debug("flow %" PRIuPTR ": on @ %" PRIu64, effp->flow, p->num_output);
} else if (!p->history && !p->dither_off) {
p->dither_off = sox_true;
memset(p->previous_errors, 0, sizeof(p->previous_errors));
memset(p->previous_outputs, 0, sizeof(p->previous_outputs));
lsx_debug("flow %" PRIuPTR ": off @ %" PRIu64, effp->flow, p->num_output);
}
}
if (!p->dither_off) {
int32_t r1 = RANQD1 >> p->precision, r2 = RANQD1 >> p->precision; /* Defer add! */
#ifdef IIR
double d1, d, output = 0;
#else
double d1, d = *ibuf++;
#endif
int i, j = 0;
CONVOLVE
assert(j == N);
p->pos = p->pos? p->pos - 1 : p->pos - 1 + N;
#ifdef IIR
d = *ibuf++ - output;
p->previous_outputs[p->pos + N] = p->previous_outputs[p->pos] = output;
#endif
d1 = (d + r1 + r2) / (1 << (32 - p->precision));
i = d1 < 0? d1 - .5 : d1 + .5;
p->previous_errors[p->pos + N] = p->previous_errors[p->pos] =
(double)i * (1 << (32 - p->precision)) - d;
if (i < (int)((unsigned)-1 << (p->precision-1)))
++effp->clips, *obuf = SOX_SAMPLE_MIN;
else if (i > (int)SOX_INT_MAX(p->precision))
++effp->clips, *obuf = SOX_INT_MAX(p->precision) << (32 - p->precision);
else *obuf = i << (32 - p->precision);
++obuf;
}
else
*obuf++ = *ibuf++;
++p->num_output;
}
return SOX_SUCCESS;
}
#undef CONVOLVE
#undef _
#undef NAME
#undef N