repositories / deb_ffmpeg.git / blame
| Commit | Line | Data |
|---|---|---|
| 2ba45a60 DM |
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 <stdint.h> | |
| 20 | #include "libavutil/avassert.h" | |
| 21 | #include "avfilter.h" | |
| 22 | #include "generate_wave_table.h" | |
| 23 | ||
| 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) | |
| 28 | { | |
| 29 | uint32_t i, phase_offset = phase / M_PI / 2 * table_size + 0.5; | |
| 30 | ||
| 31 | for (i = 0; i < table_size; i++) { | |
| 32 | uint32_t point = (i + phase_offset) % table_size; | |
| 33 | double d; | |
| 34 | ||
| 35 | switch (wave_type) { | |
| 36 | case WAVE_SIN: | |
| 37 | d = (sin((double)point / table_size * 2 * M_PI) + 1) / 2; | |
| 38 | break; | |
| 39 | case WAVE_TRI: | |
| 40 | d = (double)point * 2 / table_size; | |
| 41 | switch (4 * point / table_size) { | |
| 42 | case 0: d = d + 0.5; break; | |
| 43 | case 1: | |
| 44 | case 2: d = 1.5 - d; break; | |
| 45 | case 3: d = d - 1.5; break; | |
| 46 | } | |
| 47 | break; | |
| 48 | default: | |
| 49 | av_assert0(0); | |
| 50 | } | |
| 51 | ||
| 52 | d = d * (max - min) + min; | |
| 53 | switch (sample_fmt) { | |
| 54 | case AV_SAMPLE_FMT_FLT: { | |
| 55 | float *fp = (float *)table; | |
| 56 | *fp++ = (float)d; | |
| 57 | table = fp; | |
| 58 | continue; } | |
| 59 | case AV_SAMPLE_FMT_DBL: { | |
| 60 | double *dp = (double *)table; | |
| 61 | *dp++ = d; | |
| 62 | table = dp; | |
| 63 | continue; } | |
| 64 | } | |
| 65 | ||
| 66 | d += d < 0 ? -0.5 : 0.5; | |
| 67 | switch (sample_fmt) { | |
| 68 | case AV_SAMPLE_FMT_S16: { | |
| 69 | int16_t *sp = table; | |
| 70 | *sp++ = (int16_t)d; | |
| 71 | table = sp; | |
| 72 | continue; } | |
| 73 | case AV_SAMPLE_FMT_S32: { | |
| 74 | int32_t *ip = table; | |
| 75 | *ip++ = (int32_t)d; | |
| 76 | table = ip; | |
| 77 | continue; } | |
| 78 | default: | |
| 79 | av_assert0(0); | |
| 80 | } | |
| 81 | } | |
| 82 | } | |
| 83 | ||
| 84 |