xref: /third_party/ffmpeg/libavcodec/opusdsp.c (revision cabdff1a)
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
23static 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
46static 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
54av_cold void ff_opus_dsp_init(OpusDSP *ctx)
55{
56    ctx->postfilter = postfilter_c;
57    ctx->deemphasis = deemphasis_c;
58
59#if ARCH_AARCH64
60    ff_opus_dsp_init_aarch64(ctx);
61#elif ARCH_X86
62    ff_opus_dsp_init_x86(ctx);
63#endif
64}
65