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 31static 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 */ 52static 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 74static 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 96FILE *outfile; 97 98static void put16(int16_t v) 99{ 100 fputc( v & 0xff, outfile); 101 fputc((v >> 8) & 0xff, outfile); 102} 103 104static 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 117static 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 137int 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], '.')) != NULL && !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} 249