1 /*- 2 * Copyright (c) 2021 Hans Petter Selasky <hselasky@freebsd.org> 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 #include <sys/soundcard.h> 27 28 #include <capsicum_helpers.h> 29 #include <err.h> 30 #include <errno.h> 31 #include <fcntl.h> 32 #include <math.h> 33 #include <paths.h> 34 #include <stdbool.h> 35 #include <stdint.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #define SAMPLE_RATE_DEF 48000 /* hz */ 42 #define SAMPLE_RATE_MAX 48000 /* hz */ 43 #define SAMPLE_RATE_MIN 8000 /* hz */ 44 45 #define DURATION_DEF 150 /* ms */ 46 #define DURATION_MAX 2000 /* ms */ 47 #define DURATION_MIN 50 /* ms */ 48 49 #define GAIN_DEF 75 50 #define GAIN_MAX 100 51 #define GAIN_MIN 0 52 53 #define WAVE_POWER 1.25f 54 55 #define DEFAULT_HZ 440 56 57 #define DEFAULT_DEVICE _PATH_DEV "dsp" 58 59 static int frequency = DEFAULT_HZ; 60 static int duration_ms = DURATION_DEF; 61 static int sample_rate = SAMPLE_RATE_DEF; 62 static int gain = GAIN_DEF; 63 static const char *oss_dev = DEFAULT_DEVICE; 64 static bool background; 65 66 /* 67 * wave_function_16 68 * 69 * "phase" should be in the range [0.0f .. 1.0f> 70 * "power" should be in the range <0.0f .. 2.0f> 71 * 72 * The return value is in the range [-1.0f .. 1.0f] 73 */ 74 static float 75 wave_function_16(float phase, float power) 76 { 77 uint16_t x = phase * (1U << 16); 78 float retval; 79 uint8_t num; 80 81 /* Handle special cases, if any */ 82 switch (x) { 83 case 0xffff: 84 case 0x0000: 85 return (1.0f); 86 case 0x3fff: 87 case 0x4000: 88 case 0xBfff: 89 case 0xC000: 90 return (0.0f); 91 case 0x7FFF: 92 case 0x8000: 93 return (-1.0f); 94 default: 95 break; 96 } 97 98 /* Apply Gray coding */ 99 for (uint16_t mask = 1U << 15; mask != 1; mask /= 2) { 100 if (x & mask) 101 x ^= (mask - 1); 102 } 103 104 /* Find first set bit */ 105 for (num = 0; num != 14; num++) { 106 if (x & (1U << num)) { 107 num++; 108 break; 109 } 110 } 111 112 /* Initialize return value */ 113 retval = 0.0; 114 115 /* Compute the rest of the power series */ 116 for (; num != 14; num++) { 117 if (x & (1U << num)) { 118 retval = (1.0f - retval) / 2.0f; 119 retval = powf(retval, power); 120 } else { 121 retval = (1.0f + retval) / 2.0f; 122 retval = powf(retval, power); 123 } 124 } 125 126 /* Check if halfway */ 127 if (x & (1ULL << 14)) 128 retval = -retval; 129 130 return (retval); 131 } 132 133 static void 134 usage(void) 135 { 136 fprintf(stderr, "Usage: %s [-Bh] [-D duration_ms] [-F frequency_hz] " 137 "[-d oss_device] [-g gain] [-r sample_rate_hz]\n" 138 "\t" "-B Run in background\n" 139 "\t" "-D <duration in ms, from %d ms to %d ms, default %d ms>\n" 140 "\t" "-F <frequency in Hz, default %d Hz>\n" 141 "\t" "-d <OSS device, default %s>\n" 142 "\t" "-g <gain from %d to %d, default %d>\n" 143 "\t" "-h Show usage\n" 144 "\t" "-r <sample rate in Hz, from %d Hz to %d Hz, default %d Hz>\n", 145 getprogname(), 146 DURATION_MIN, DURATION_MAX, DURATION_DEF, 147 DEFAULT_HZ, 148 DEFAULT_DEVICE, 149 GAIN_MIN, GAIN_MAX, GAIN_DEF, 150 SAMPLE_RATE_MIN, SAMPLE_RATE_MAX, SAMPLE_RATE_DEF); 151 exit(1); 152 } 153 154 int 155 main(int argc, char **argv) 156 { 157 float *buffer; 158 size_t slope; 159 size_t size; 160 size_t off; 161 float a; 162 float d; 163 float p; 164 int c; 165 int f; 166 167 while ((c = getopt(argc, argv, "BF:D:r:g:d:h")) != -1) { 168 switch (c) { 169 case 'F': 170 frequency = strtol(optarg, NULL, 10); 171 break; 172 case 'D': 173 duration_ms = strtol(optarg, NULL, 10); 174 if (duration_ms < DURATION_MIN || 175 duration_ms > DURATION_MAX) 176 usage(); 177 break; 178 case 'r': 179 sample_rate = strtol(optarg, NULL, 10); 180 if (sample_rate < SAMPLE_RATE_MIN || 181 sample_rate > SAMPLE_RATE_MAX) 182 usage(); 183 break; 184 case 'g': 185 gain = strtol(optarg, NULL, 10); 186 if (gain < GAIN_MIN || 187 gain > GAIN_MAX) 188 usage(); 189 break; 190 case 'd': 191 oss_dev = optarg; 192 break; 193 case 'B': 194 background = true; 195 break; 196 default: 197 usage(); 198 break; 199 } 200 } 201 202 if (background && daemon(0, 0) != 0) 203 errx(1, "daemon(0,0) failed"); 204 205 f = open(oss_dev, O_WRONLY); 206 if (f < 0) 207 err(1, "Failed to open '%s'", oss_dev); 208 209 if (caph_enter() == -1) 210 err(1, "Failed to enter capability mode"); 211 212 c = 1; /* mono */ 213 if (ioctl(f, SOUND_PCM_WRITE_CHANNELS, &c) != 0) 214 errx(1, "ioctl SOUND_PCM_WRITE_CHANNELS(1) failed"); 215 216 c = AFMT_FLOAT; 217 if (ioctl(f, SNDCTL_DSP_SETFMT, &c) != 0) 218 errx(1, "ioctl SNDCTL_DSP_SETFMT(AFMT_FLOAT) failed"); 219 220 if (ioctl(f, SNDCTL_DSP_SPEED, &sample_rate) != 0) 221 errx(1, "ioctl SNDCTL_DSP_SPEED(%d) failed", sample_rate); 222 223 c = (2 << 16); 224 while ((1ULL << (c & 63)) < (size_t)(4 * sample_rate / 50)) 225 c++; 226 if (ioctl(f, SNDCTL_DSP_SETFRAGMENT, &c)) 227 errx(1, "ioctl SNDCTL_DSP_SETFRAGMENT(0x%x) failed", c); 228 229 if (ioctl(f, SNDCTL_DSP_GETODELAY, &c) != 0) 230 errx(1, "ioctl SNDCTL_DSP_GETODELAY failed"); 231 232 size = ((sample_rate * duration_ms) + 999) / 1000; 233 buffer = malloc(sizeof(buffer[0]) * size); 234 if (buffer == NULL) 235 errx(1, "out of memory"); 236 237 /* compute slope duration in samples */ 238 slope = (DURATION_MIN * sample_rate) / 2000; 239 240 /* compute base gain */ 241 a = powf(65536.0f, (float)gain / (float)GAIN_MAX) / 65536.0f; 242 243 /* set initial phase and delta */ 244 p = 0; 245 d = (float)frequency / (float)sample_rate; 246 247 /* compute wave */ 248 for (p = off = 0; off != size; off++, p += d) { 249 float sample; 250 251 p = p - floorf(p); 252 sample = a * wave_function_16(p, WAVE_POWER); 253 254 if (off < slope) 255 sample = sample * off / (float)slope; 256 else if (off > (size - slope)) 257 sample = sample * (size - off - 1) / (float)slope; 258 259 buffer[off] = sample; 260 } 261 262 if (write(f, buffer, size * sizeof(buffer[0])) != 263 (ssize_t)(size * sizeof(buffer[0]))) 264 errx(1, "failed writing to DSP device(%s)", oss_dev); 265 266 free(buffer); 267 268 /* wait for data to be written */ 269 while (ioctl(f, SNDCTL_DSP_GETODELAY, &c) == 0) { 270 if (c == 0) 271 break; 272 usleep(10000); 273 } 274 275 /* wait for audio to go out */ 276 usleep(50000); 277 close(f); 278 279 return (0); 280 } 281