FFmpeg
opusdsp.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 #include "libavutil/attributes.h"
21 #include "opusdsp.h"
22 
23 static void postfilter_c(float *data, int period, float *gains, int len)
24 {
25  const float g0 = gains[0];
26  const float g1 = gains[1];
27  const float g2 = gains[2];
28 
29  float x4 = data[-period - 2];
30  float x3 = data[-period - 1];
31  float x2 = data[-period + 0];
32  float x1 = data[-period + 1];
33 
34  for (int i = 0; i < len; i++) {
35  float x0 = data[i - period + 2];
36  data[i] += g0 * x2 +
37  g1 * (x1 + x3) +
38  g2 * (x0 + x4);
39  x4 = x3;
40  x3 = x2;
41  x2 = x1;
42  x1 = x0;
43  }
44 }
45 
46 static float deemphasis_c(float *y, float *x, float coeff, int len)
47 {
48  for (int i = 0; i < len; i++)
49  coeff = y[i] = x[i] + coeff*CELT_EMPH_COEFF;
50 
51  return coeff;
52 }
53 
55 {
56  ctx->postfilter = postfilter_c;
57  ctx->deemphasis = deemphasis_c;
58 
59 #if ARCH_AARCH64
61 #elif ARCH_X86
63 #endif
64 }
ff_opus_dsp_init_aarch64
av_cold void ff_opus_dsp_init_aarch64(OpusDSP *ctx)
Definition: opusdsp_init.c:28
deemphasis_c
static float deemphasis_c(float *y, float *x, float coeff, int len)
Definition: opusdsp.c:46
opusdsp.h
data
const char data[16]
Definition: mxf.c:146
postfilter_c
static void postfilter_c(float *data, int period, float *gains, int len)
Definition: opusdsp.c:23
av_cold
#define av_cold
Definition: attributes.h:90
ctx
AVFormatContext * ctx
Definition: movenc.c:48
period
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without period
Definition: writing_filters.txt:89
attributes.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
ff_opus_dsp_init_x86
void ff_opus_dsp_init_x86(OpusDSP *ctx)
Definition: opusdsp_init.c:28
len
int len
Definition: vorbis_enc_data.h:426
CELT_EMPH_COEFF
#define CELT_EMPH_COEFF
Definition: opusdsp.h:22
ff_opus_dsp_init
av_cold void ff_opus_dsp_init(OpusDSP *ctx)
Definition: opusdsp.c:54
coeff
static const double coeff[2][5]
Definition: vf_owdenoise.c:78
OpusDSP
Definition: opusdsp.h:24