tests/audiogen.c

   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 Libav.
   8  *
   9  * Libav 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  * Libav 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 Libav; 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 cosinus */
  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], '.')) != NULL && !strcmp(ext, ".wav"))
 181         put_wav_header(sample_rate, nb_channels, 6 * sample_rate);
 182
 183     /* 1 second of single freq sinus 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 }