2 * This file is part of FFmpeg.
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.
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.
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
20 #include "libavutil/avassert.h"
22 #include "generate_wave_table.h"
24 void ff_generate_wave_table(enum WaveType wave_type,
25 enum AVSampleFormat sample_fmt,
26 void *table, int table_size,
27 double min, double max, double phase)
29 uint32_t i, phase_offset = phase / M_PI / 2 * table_size + 0.5;
31 for (i = 0; i < table_size; i++) {
32 uint32_t point = (i + phase_offset) % table_size;
37 d = (sin((double)point / table_size * 2 * M_PI) + 1) / 2;
40 d = (double)point * 2 / table_size;
41 switch (4 * point / table_size) {
42 case 0: d = d + 0.5; break;
44 case 2: d = 1.5 - d; break;
45 case 3: d = d - 1.5; break;
52 d = d * (max - min) + min;
54 case AV_SAMPLE_FMT_FLT: {
55 float *fp = (float *)table;
59 case AV_SAMPLE_FMT_DBL: {
60 double *dp = (double *)table;
66 d += d < 0 ? -0.5 : 0.5;
68 case AV_SAMPLE_FMT_S16: {
73 case AV_SAMPLE_FMT_S32: {