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audiogen.c
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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);
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 }
const char const char void * val
Definition: avisynth_c.h:771
static unsigned int myrnd(unsigned int *seed_ptr, int n)
Definition: audiogen.c:31
#define MAX_CHANNELS
Definition: audiogen.c:29
static void put32(uint32_t v)
Definition: audiogen.c:104
#define SAMPLE_SIZE
Definition: audiogen.c:114
channels
Definition: aptx.c:30
#define HEADER_SIZE
Definition: audiogen.c:112
#define f(width, name)
Definition: cbs_vp9.c:255
#define FRAC_BITS
Definition: audiogen.c:46
#define FMT_SIZE
Definition: audiogen.c:113
#define FRAC_ONE
Definition: audiogen.c:47
static void put16(int16_t v)
Definition: audiogen.c:98
static const unsigned short cos_table[(1<< COS_TABLE_BITS)+2]
Definition: audiogen.c:52
static int int_cos(int a)
Definition: audiogen.c:74
#define CSHIFT
Definition: audiogen.c:72
int n
Definition: avisynth_c.h:684
#define WFORMAT_PCM
Definition: audiogen.c:115
sample_rate
static unsigned int seed
Definition: videogen.c:78
static void put_wav_header(int sample_rate, int channels, int nb_samples)
Definition: audiogen.c:117
#define COS_TABLE_BITS
Definition: audiogen.c:49
int main(int argc, char **argv)
Definition: audiogen.c:137
int nb_channels
FILE * outfile
Definition: audiogen.c:96