| 1 | /* |
| 2 | * Generate a synthetic stereo sound. |
| 3 | * NOTE: No floats are used to guarantee bitexact output. |
| 4 | * |
| 5 | * Copyright (c) 2002 Fabrice Bellard |
| 6 | * |
| 7 | * This file is part of FFmpeg. |
| 8 | * |
| 9 | * FFmpeg is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU Lesser General Public |
| 11 | * License as published by the Free Software Foundation; either |
| 12 | * version 2.1 of the License, or (at your option) any later version. |
| 13 | * |
| 14 | * FFmpeg is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 17 | * Lesser General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU Lesser General Public |
| 20 | * License along with FFmpeg; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 22 | */ |
| 23 | |
| 24 | #include <stdlib.h> |
| 25 | #include <stdint.h> |
| 26 | #include <stdio.h> |
| 27 | #include <string.h> |
| 28 | |
| 29 | #define MAX_CHANNELS 8 |
| 30 | |
| 31 | static unsigned int myrnd(unsigned int *seed_ptr, int n) |
| 32 | { |
| 33 | unsigned int seed, val; |
| 34 | |
| 35 | seed = *seed_ptr; |
| 36 | seed = (seed * 314159) + 1; |
| 37 | if (n == 256) { |
| 38 | val = seed >> 24; |
| 39 | } else { |
| 40 | val = seed % n; |
| 41 | } |
| 42 | *seed_ptr = seed; |
| 43 | return val; |
| 44 | } |
| 45 | |
| 46 | #define FRAC_BITS 16 |
| 47 | #define FRAC_ONE (1 << FRAC_BITS) |
| 48 | |
| 49 | #define COS_TABLE_BITS 7 |
| 50 | |
| 51 | /* integer cosine */ |
| 52 | static const unsigned short cos_table[(1 << COS_TABLE_BITS) + 2] = { |
| 53 | 0x8000, 0x7ffe, 0x7ff6, 0x7fea, 0x7fd9, 0x7fc2, 0x7fa7, 0x7f87, |
| 54 | 0x7f62, 0x7f38, 0x7f0a, 0x7ed6, 0x7e9d, 0x7e60, 0x7e1e, 0x7dd6, |
| 55 | 0x7d8a, 0x7d3a, 0x7ce4, 0x7c89, 0x7c2a, 0x7bc6, 0x7b5d, 0x7aef, |
| 56 | 0x7a7d, 0x7a06, 0x798a, 0x790a, 0x7885, 0x77fb, 0x776c, 0x76d9, |
| 57 | 0x7642, 0x75a6, 0x7505, 0x7460, 0x73b6, 0x7308, 0x7255, 0x719e, |
| 58 | 0x70e3, 0x7023, 0x6f5f, 0x6e97, 0x6dca, 0x6cf9, 0x6c24, 0x6b4b, |
| 59 | 0x6a6e, 0x698c, 0x68a7, 0x67bd, 0x66d0, 0x65de, 0x64e9, 0x63ef, |
| 60 | 0x62f2, 0x61f1, 0x60ec, 0x5fe4, 0x5ed7, 0x5dc8, 0x5cb4, 0x5b9d, |
| 61 | 0x5a82, 0x5964, 0x5843, 0x571e, 0x55f6, 0x54ca, 0x539b, 0x5269, |
| 62 | 0x5134, 0x4ffb, 0x4ec0, 0x4d81, 0x4c40, 0x4afb, 0x49b4, 0x486a, |
| 63 | 0x471d, 0x45cd, 0x447b, 0x4326, 0x41ce, 0x4074, 0x3f17, 0x3db8, |
| 64 | 0x3c57, 0x3af3, 0x398d, 0x3825, 0x36ba, 0x354e, 0x33df, 0x326e, |
| 65 | 0x30fc, 0x2f87, 0x2e11, 0x2c99, 0x2b1f, 0x29a4, 0x2827, 0x26a8, |
| 66 | 0x2528, 0x23a7, 0x2224, 0x209f, 0x1f1a, 0x1d93, 0x1c0c, 0x1a83, |
| 67 | 0x18f9, 0x176e, 0x15e2, 0x1455, 0x12c8, 0x113a, 0x0fab, 0x0e1c, |
| 68 | 0x0c8c, 0x0afb, 0x096b, 0x07d9, 0x0648, 0x04b6, 0x0324, 0x0192, |
| 69 | 0x0000, 0x0000, |
| 70 | }; |
| 71 | |
| 72 | #define CSHIFT (FRAC_BITS - COS_TABLE_BITS - 2) |
| 73 | |
| 74 | static int int_cos(int a) |
| 75 | { |
| 76 | int neg, v, f; |
| 77 | const unsigned short *p; |
| 78 | |
| 79 | a = a & (FRAC_ONE - 1); /* modulo 2 * pi */ |
| 80 | if (a >= (FRAC_ONE / 2)) |
| 81 | a = FRAC_ONE - a; |
| 82 | neg = 0; |
| 83 | if (a > (FRAC_ONE / 4)) { |
| 84 | neg = -1; |
| 85 | a = (FRAC_ONE / 2) - a; |
| 86 | } |
| 87 | p = cos_table + (a >> CSHIFT); |
| 88 | /* linear interpolation */ |
| 89 | f = a & ((1 << CSHIFT) - 1); |
| 90 | v = p[0] + (((p[1] - p[0]) * f + (1 << (CSHIFT - 1))) >> CSHIFT); |
| 91 | v = (v ^ neg) - neg; |
| 92 | v = v << (FRAC_BITS - 15); |
| 93 | return v; |
| 94 | } |
| 95 | |
| 96 | FILE *outfile; |
| 97 | |
| 98 | static void put16(int16_t v) |
| 99 | { |
| 100 | fputc( v & 0xff, outfile); |
| 101 | fputc((v >> 8) & 0xff, outfile); |
| 102 | } |
| 103 | |
| 104 | static void put32(uint32_t v) |
| 105 | { |
| 106 | fputc( v & 0xff, outfile); |
| 107 | fputc((v >> 8) & 0xff, outfile); |
| 108 | fputc((v >> 16) & 0xff, outfile); |
| 109 | fputc((v >> 24) & 0xff, outfile); |
| 110 | } |
| 111 | |
| 112 | #define HEADER_SIZE 46 |
| 113 | #define FMT_SIZE 18 |
| 114 | #define SAMPLE_SIZE 2 |
| 115 | #define WFORMAT_PCM 0x0001 |
| 116 | |
| 117 | static void put_wav_header(int sample_rate, int channels, int nb_samples) |
| 118 | { |
| 119 | int block_align = SAMPLE_SIZE * channels; |
| 120 | int data_size = block_align * nb_samples; |
| 121 | |
| 122 | fputs("RIFF", outfile); |
| 123 | put32(HEADER_SIZE + data_size); |
| 124 | fputs("WAVEfmt ", outfile); |
| 125 | put32(FMT_SIZE); |
| 126 | put16(WFORMAT_PCM); |
| 127 | put16(channels); |
| 128 | put32(sample_rate); |
| 129 | put32(block_align * sample_rate); |
| 130 | put16(block_align); |
| 131 | put16(SAMPLE_SIZE * 8); |
| 132 | put16(0); |
| 133 | fputs("data", outfile); |
| 134 | put32(data_size); |
| 135 | } |
| 136 | |
| 137 | int main(int argc, char **argv) |
| 138 | { |
| 139 | int i, a, v, j, f, amp, ampa; |
| 140 | unsigned int seed = 1; |
| 141 | int tabf1[MAX_CHANNELS], tabf2[MAX_CHANNELS]; |
| 142 | int taba[MAX_CHANNELS]; |
| 143 | int sample_rate = 44100; |
| 144 | int nb_channels = 2; |
| 145 | char *ext; |
| 146 | |
| 147 | if (argc < 2 || argc > 5) { |
| 148 | printf("usage: %s file [<sample rate> [<channels>] [<random seed>]]\n" |
| 149 | "generate a test raw 16 bit audio stream\n" |
| 150 | "If the file extension is .wav a WAVE header will be added.\n" |
| 151 | "default: 44100 Hz stereo\n", argv[0]); |
| 152 | exit(1); |
| 153 | } |
| 154 | |
| 155 | if (argc > 2) { |
| 156 | sample_rate = atoi(argv[2]); |
| 157 | if (sample_rate <= 0) { |
| 158 | fprintf(stderr, "invalid sample rate: %d\n", sample_rate); |
| 159 | return 1; |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | if (argc > 3) { |
| 164 | nb_channels = atoi(argv[3]); |
| 165 | if (nb_channels < 1 || nb_channels > MAX_CHANNELS) { |
| 166 | fprintf(stderr, "invalid number of channels: %d\n", nb_channels); |
| 167 | return 1; |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | if (argc > 4) |
| 172 | seed = atoi(argv[4]); |
| 173 | |
| 174 | outfile = fopen(argv[1], "wb"); |
| 175 | if (!outfile) { |
| 176 | perror(argv[1]); |
| 177 | return 1; |
| 178 | } |
| 179 | |
| 180 | if ((ext = strrchr(argv[1], '.')) && !strcmp(ext, ".wav")) |
| 181 | put_wav_header(sample_rate, nb_channels, 6 * sample_rate); |
| 182 | |
| 183 | /* 1 second of single freq sine at 1000 Hz */ |
| 184 | a = 0; |
| 185 | for (i = 0; i < 1 * sample_rate; i++) { |
| 186 | v = (int_cos(a) * 10000) >> FRAC_BITS; |
| 187 | for (j = 0; j < nb_channels; j++) |
| 188 | put16(v); |
| 189 | a += (1000 * FRAC_ONE) / sample_rate; |
| 190 | } |
| 191 | |
| 192 | /* 1 second of varying frequency between 100 and 10000 Hz */ |
| 193 | a = 0; |
| 194 | for (i = 0; i < 1 * sample_rate; i++) { |
| 195 | v = (int_cos(a) * 10000) >> FRAC_BITS; |
| 196 | for (j = 0; j < nb_channels; j++) |
| 197 | put16(v); |
| 198 | f = 100 + (((10000 - 100) * i) / sample_rate); |
| 199 | a += (f * FRAC_ONE) / sample_rate; |
| 200 | } |
| 201 | |
| 202 | /* 0.5 second of low amplitude white noise */ |
| 203 | for (i = 0; i < sample_rate / 2; i++) { |
| 204 | v = myrnd(&seed, 20000) - 10000; |
| 205 | for (j = 0; j < nb_channels; j++) |
| 206 | put16(v); |
| 207 | } |
| 208 | |
| 209 | /* 0.5 second of high amplitude white noise */ |
| 210 | for (i = 0; i < sample_rate / 2; i++) { |
| 211 | v = myrnd(&seed, 65535) - 32768; |
| 212 | for (j = 0; j < nb_channels; j++) |
| 213 | put16(v); |
| 214 | } |
| 215 | |
| 216 | /* 1 second of unrelated ramps for each channel */ |
| 217 | for (j = 0; j < nb_channels; j++) { |
| 218 | taba[j] = 0; |
| 219 | tabf1[j] = 100 + myrnd(&seed, 5000); |
| 220 | tabf2[j] = 100 + myrnd(&seed, 5000); |
| 221 | } |
| 222 | for (i = 0; i < 1 * sample_rate; i++) { |
| 223 | for (j = 0; j < nb_channels; j++) { |
| 224 | v = (int_cos(taba[j]) * 10000) >> FRAC_BITS; |
| 225 | put16(v); |
| 226 | f = tabf1[j] + (((tabf2[j] - tabf1[j]) * i) / sample_rate); |
| 227 | taba[j] += (f * FRAC_ONE) / sample_rate; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | /* 2 seconds of 500 Hz with varying volume */ |
| 232 | a = 0; |
| 233 | ampa = 0; |
| 234 | for (i = 0; i < 2 * sample_rate; i++) { |
| 235 | for (j = 0; j < nb_channels; j++) { |
| 236 | amp = ((FRAC_ONE + int_cos(ampa)) * 5000) >> FRAC_BITS; |
| 237 | if (j & 1) |
| 238 | amp = 10000 - amp; |
| 239 | v = (int_cos(a) * amp) >> FRAC_BITS; |
| 240 | put16(v); |
| 241 | a += (500 * FRAC_ONE) / sample_rate; |
| 242 | ampa += (2 * FRAC_ONE) / sample_rate; |
| 243 | } |
| 244 | } |
| 245 | |
| 246 | fclose(outfile); |
| 247 | return 0; |
| 248 | } |