FFmpeg
libswresample
dither_template.c
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/*
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* This file is part of libswresample
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*
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* libswresample is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* libswresample is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with libswresample; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#if defined(TEMPLATE_DITHER_DBL)
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# define RENAME(N) N ## _double
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# define DELEM double
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# define CLIP(v) while(0)
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#elif defined(TEMPLATE_DITHER_FLT)
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# define RENAME(N) N ## _float
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# define DELEM float
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# define CLIP(v) while(0)
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#elif defined(TEMPLATE_DITHER_S32)
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# define RENAME(N) N ## _int32
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# define DELEM int32_t
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# define CLIP(v) v = FFMAX(FFMIN(v, INT32_MAX), INT32_MIN)
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#elif defined(TEMPLATE_DITHER_S16)
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# define RENAME(N) N ## _int16
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# define DELEM int16_t
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# define CLIP(v) v = FFMAX(FFMIN(v, INT16_MAX), INT16_MIN)
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#else
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ERROR
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#endif
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void
RENAME
(swri_noise_shaping)(
SwrContext
*
s
,
AudioData
*dsts,
const
AudioData
*srcs,
const
AudioData
*noises,
int
count){
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int
pos
=
s
->dither.ns_pos;
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int
i
, j, ch;
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int
taps =
s
->dither.ns_taps;
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float
S
=
s
->dither.ns_scale;
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float
S_1 =
s
->dither.ns_scale_1;
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av_assert2
((taps&3) != 2);
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av_assert2
((taps&3) != 3 ||
s
->dither.ns_coeffs[taps] == 0);
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for
(ch=0; ch<srcs->ch_count; ch++) {
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const
float
*
noise
= ((
const
float
*)noises->ch[ch]) +
s
->dither.noise_pos;
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const
DELEM *
src
= (
const
DELEM*)srcs->ch[ch];
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DELEM *
dst
= (DELEM*)dsts->ch[ch];
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float
*ns_errors =
s
->dither.ns_errors[ch];
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const
float
*ns_coeffs =
s
->dither.ns_coeffs;
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pos
=
s
->dither.ns_pos;
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for
(
i
=0;
i
<count;
i
++) {
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double
d1, d =
src
[
i
]*S_1;
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for
(j=0; j<taps-2; j+=4) {
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d -= ns_coeffs[j ] * ns_errors[
pos
+ j ]
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+ns_coeffs[j + 1] * ns_errors[
pos
+ j + 1]
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+ns_coeffs[j + 2] * ns_errors[
pos
+ j + 2]
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+ns_coeffs[j + 3] * ns_errors[
pos
+ j + 3];
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}
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if
(j < taps)
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d -= ns_coeffs[j] * ns_errors[
pos
+ j];
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pos
=
pos
?
pos
- 1 : taps - 1;
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d1 =
rint
(d +
noise
[
i
]);
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ns_errors[
pos
+ taps] = ns_errors[
pos
] = d1 - d;
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d1 *=
S
;
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CLIP
(d1);
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dst
[
i
] = d1;
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}
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}
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s
->dither.ns_pos =
pos
;
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}
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#undef RENAME
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#undef DELEM
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#undef CLIP
S
#define S(s, c, i)
Definition:
flacdsp_template.c:46
AudioData
Definition:
swresample_internal.h:45
noise
static int noise(AVBSFContext *ctx, AVPacket *pkt)
Definition:
noise.c:127
s
#define s(width, name)
Definition:
cbs_vp9.c:198
SwrContext
The libswresample context.
Definition:
swresample_internal.h:95
rint
#define rint
Definition:
tablegen.h:41
ERROR
static void ERROR(const char *str)
Definition:
audio_fifo.c:58
dst
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition:
dsp.h:83
av_assert2
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
Definition:
avassert.h:67
i
#define i(width, name, range_min, range_max)
Definition:
cbs_h2645.c:256
pos
unsigned int pos
Definition:
spdifenc.c:414
RENAME
#define RENAME(element)
Definition:
ac3enc_template.c:44
CLIP
@ CLIP
Definition:
qdrw.c:37
src
#define src
Definition:
vp8dsp.c:248
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