xref: /freebsd/usr.bin/beep/beep.c (revision 66df505066f51e6d8411b966765d828817f88971)
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 <err.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <math.h>
32 #include <paths.h>
33 #include <stdbool.h>
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 #define	SAMPLE_RATE_DEF 48000		/* hz */
41 #define	SAMPLE_RATE_MAX 48000		/* hz */
42 #define	SAMPLE_RATE_MIN 8000		/* hz */
43 
44 #define	DURATION_DEF 150		/* ms */
45 #define	DURATION_MAX 2000		/* ms */
46 #define	DURATION_MIN 50			/* ms */
47 
48 #define	GAIN_DEF 75
49 #define	GAIN_MAX 100
50 #define	GAIN_MIN 0
51 
52 #define	WAVE_POWER 1.25f
53 
54 #define	DEFAULT_HZ 440
55 
56 #define	DEFAULT_DEVICE _PATH_DEV "dsp"
57 
58 static int frequency = DEFAULT_HZ;
59 static int duration_ms = DURATION_DEF;
60 static int sample_rate = SAMPLE_RATE_DEF;
61 static int gain = GAIN_DEF;
62 static const char *oss_dev = DEFAULT_DEVICE;
63 static bool background;
64 
65 /*
66  * wave_function_16
67  *
68  * "phase" should be in the range [0.0f .. 1.0f>
69  * "power" should be in the range <0.0f .. 2.0f>
70  *
71  * The return value is in the range [-1.0f .. 1.0f]
72  */
73 static float
74 wave_function_16(float phase, float power)
75 {
76 	uint16_t x = phase * (1U << 16);
77 	float retval;
78 	uint8_t num;
79 
80 	/* Handle special cases, if any */
81 	switch (x) {
82 	case 0xffff:
83 	case 0x0000:
84 		return (1.0f);
85 	case 0x3fff:
86 	case 0x4000:
87 	case 0xBfff:
88 	case 0xC000:
89 		return (0.0f);
90 	case 0x7FFF:
91 	case 0x8000:
92 		return (-1.0f);
93 	default:
94 		break;
95 	}
96 
97 	/* Apply Gray coding */
98 	for (uint16_t mask = 1U << 15; mask != 1; mask /= 2) {
99 		if (x & mask)
100 			x ^= (mask - 1);
101 	}
102 
103 	/* Find first set bit */
104 	for (num = 0; num != 14; num++) {
105 		if (x & (1U << num)) {
106 			num++;
107 			break;
108 		}
109 	}
110 
111 	/* Initialize return value */
112 	retval = 0.0;
113 
114 	/* Compute the rest of the power series */
115 	for (; num != 14; num++) {
116 		if (x & (1U << num)) {
117 			retval = (1.0f - retval) / 2.0f;
118 			retval = powf(retval, power);
119 		} else {
120 			retval = (1.0f + retval) / 2.0f;
121 			retval = powf(retval, power);
122 		}
123 	}
124 
125 	/* Check if halfway */
126 	if (x & (1ULL << 14))
127 		retval = -retval;
128 
129 	return (retval);
130 }
131 
132 static void
133 usage(void)
134 {
135 	fprintf(stderr, "Usage: %s [parameters]\n"
136 	    "\t" "-F <frequency in HZ, default %d Hz>\n"
137 	    "\t" "-D <duration in ms, from %d ms to %d ms, default %d ms>\n"
138 	    "\t" "-r <sample rate in HZ, from %d Hz to %d Hz, default %d Hz>\n"
139 	    "\t" "-d <OSS device (default %s)>\n"
140 	    "\t" "-g <gain from %d to %d, default %d>\n"
141 	    "\t" "-B Run in background\n"
142 	    "\t" "-h Show usage\n",
143 	    getprogname(),
144 	    DEFAULT_HZ,
145 	    DURATION_MIN, DURATION_MAX, DURATION_DEF,
146 	    SAMPLE_RATE_MIN, SAMPLE_RATE_MAX, SAMPLE_RATE_DEF,
147 	    DEFAULT_DEVICE,
148 	    GAIN_MIN, GAIN_MAX, GAIN_DEF);
149 	exit(1);
150 }
151 
152 int
153 main(int argc, char **argv)
154 {
155 	int32_t *buffer;
156 	size_t slope;
157 	size_t size;
158 	size_t off;
159 	float a;
160 	float d;
161 	float p;
162 	int c;
163 	int f;
164 
165 	while ((c = getopt(argc, argv, "BF:D:r:g:d:h")) != -1) {
166 		switch (c) {
167 		case 'F':
168 			frequency = strtol(optarg, NULL, 10);
169 			break;
170 		case 'D':
171 			duration_ms = strtol(optarg, NULL, 10);
172 			if (duration_ms < DURATION_MIN ||
173 			    duration_ms > DURATION_MAX)
174 				usage();
175 			break;
176 		case 'r':
177 			sample_rate = strtol(optarg, NULL, 10);
178 			if (sample_rate < SAMPLE_RATE_MIN ||
179 			    sample_rate > SAMPLE_RATE_MAX)
180 				usage();
181 			break;
182 		case 'g':
183 			gain = strtol(optarg, NULL, 10);
184 			if (gain < GAIN_MIN ||
185 			    gain > GAIN_MAX)
186 				usage();
187 			break;
188 		case 'd':
189 			oss_dev = optarg;
190 			break;
191 		case 'B':
192 			background = true;
193 			break;
194 		default:
195 			usage();
196 			break;
197 		}
198 	}
199 
200 	if (background && daemon(0, 0) != 0)
201 		errx(1, "daemon(0,0) failed");
202 
203 	f = open(oss_dev, O_WRONLY);
204 	if (f < 0)
205 		errx(1, "Failed to open '%s'", oss_dev);
206 
207 	c = 1;				/* mono */
208 	if (ioctl(f, SOUND_PCM_WRITE_CHANNELS, &c) != 0)
209 		errx(1, "ioctl SOUND_PCM_WRITE_CHANNELS(1) failed");
210 
211 	c = AFMT_S32_NE;
212 	if (ioctl(f, SNDCTL_DSP_SETFMT, &c) != 0)
213 		errx(1, "ioctl SNDCTL_DSP_SETFMT(AFMT_S32_NE) failed");
214 
215 	if (ioctl(f, SNDCTL_DSP_SPEED, &sample_rate) != 0)
216 		errx(1, "ioctl SNDCTL_DSP_SPEED(%d) failed", sample_rate);
217 
218 	c = (2 << 16);
219 	while ((1ULL << (c & 63)) < (size_t)(4 * sample_rate / 50))
220 		c++;
221 	if (ioctl(f, SNDCTL_DSP_SETFRAGMENT, &c))
222 		errx(1, "ioctl SNDCTL_DSP_SETFRAGMENT(0x%x) failed", c);
223 
224 	if (ioctl(f, SNDCTL_DSP_GETODELAY, &c) != 0)
225 		errx(1, "ioctl SNDCTL_DSP_GETODELAY failed");
226 
227 	size = ((sample_rate * duration_ms) + 999) / 1000;
228 	buffer = malloc(sizeof(buffer[0]) * size);
229 	if (buffer == NULL)
230 		errx(1, "out of memory");
231 
232 	/* compute slope duration in samples */
233 	slope = (DURATION_MIN * sample_rate) / 2000;
234 
235 	/* compute base gain */
236 	a = powf(65536.0f, (float)gain / (float)GAIN_MAX) / 65536.0f;
237 
238 	/* set initial phase and delta */
239 	p = 0;
240 	d = (float)frequency / (float)sample_rate;
241 
242 	/* compute wave */
243 	for (p = off = 0; off != size; off++, p += d) {
244 		float sample;
245 
246 		p = p - floorf(p);
247 		sample = a * wave_function_16(p, WAVE_POWER);
248 
249 		if (off < slope)
250 			sample = sample * off / (float)slope;
251 		else if (off > (size - slope))
252 			sample = sample * (size - off - 1) / (float)slope;
253 
254 		buffer[off] = sample * 0x7fffff00;
255 	}
256 
257 	if (write(f, buffer, size * sizeof(buffer[0])) !=
258 	    (ssize_t)(size * sizeof(buffer[0])))
259 		errx(1, "failed writing to DSP device(%s)", oss_dev);
260 
261 	free(buffer);
262 
263 	/* wait for data to be written */
264 	while (ioctl(f, SNDCTL_DSP_GETODELAY, &c) == 0) {
265 		if (c == 0)
266 			break;
267 		usleep(10000);
268 	}
269 
270 	/* wait for audio to go out */
271 	usleep(50000);
272 	close(f);
273 
274 	return (0);
275 }
276