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