1 /*
2  * Copyright (c) 2022, 2023 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "config.h"
18 
19 #include <limits.h>
20 
21 #include <assert.h>
22 #include <errno.h>
23 #include <poll.h>
24 #include <signal.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <stdint.h>
28 #include <string.h>
29 #include <syslog.h>
30 #include <unistd.h>
31 
32 #include "amused.h"
33 #include "log.h"
34 #include "xmalloc.h"
35 
36 struct pollfd		*player_pfds;
37 int			 player_nfds;
38 static struct imsgbuf	*ibuf;
39 
40 static int nextfd = -1;
41 static int64_t samples;
42 static int64_t duration;
43 static unsigned int current_rate;
44 
45 volatile sig_atomic_t halted;
46 
47 static void
48 player_signal_handler(int signo)
49 {
50 	halted = 1;
51 }
52 
53 int
54 player_setup(unsigned int bits, unsigned int rate, unsigned int channels)
55 {
56 	log_debug("%s: bits=%u, rate=%u, channels=%u", __func__,
57 	    bits, rate, channels);
58 
59 	current_rate = rate;
60 	return audio_setup(bits, rate, channels, player_pfds + 1, player_nfds);
61 }
62 
63 void
64 player_setduration(int64_t d)
65 {
66 	int64_t seconds;
67 
68 	duration = d;
69 	seconds = duration / current_rate;
70 	imsg_compose(ibuf, IMSG_LEN, 0, 0, -1, &seconds, sizeof(seconds));
71 	imsg_flush(ibuf);
72 }
73 
74 static void
75 player_onmove(void *arg, int delta)
76 {
77 	static int64_t reported;
78 	int64_t sec;
79 
80 	samples += delta;
81 	if (llabs(samples - reported) >= current_rate) {
82 		reported = samples;
83 		sec = samples / current_rate;
84 
85 		imsg_compose(ibuf, IMSG_POS, 0, 0, -1, &sec, sizeof(sec));
86 		imsg_flush(ibuf);
87 	}
88 }
89 
90 void
91 player_setpos(int64_t pos)
92 {
93 	samples = pos;
94 	player_onmove(NULL, 0);
95 }
96 
97 /* process only one message */
98 static int
99 player_dispatch(int64_t *s, int wait)
100 {
101 	struct player_seek seek;
102 	struct pollfd	pfd;
103 	struct imsg	imsg;
104 	ssize_t		n;
105 	int		ret;
106 
107 	if (halted != 0)
108 		return IMSG_STOP;
109 
110 again:
111 	if ((n = imsg_get(ibuf, &imsg)) == -1)
112 		fatal("imsg_get");
113 	if (n == 0) {
114 		if (!wait)
115 			return -1;
116 
117 		pfd.fd = ibuf->fd;
118 		pfd.events = POLLIN;
119 		if (poll(&pfd, 1, INFTIM) == -1)
120 			fatal("poll");
121 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
122 			fatal("imsg_read");
123 		if (n == 0)
124 			fatalx("pipe closed");
125 		goto again;
126 	}
127 
128 	ret = imsg.hdr.type;
129 	switch (imsg.hdr.type) {
130 	case IMSG_PLAY:
131 		if (nextfd != -1)
132 			fatalx("track already enqueued");
133 		if ((nextfd = imsg.fd) == -1)
134 			fatalx("%s: got invalid file descriptor", __func__);
135 		log_debug("song enqueued");
136 		ret = IMSG_STOP;
137 		break;
138 	case IMSG_RESUME:
139 	case IMSG_PAUSE:
140 	case IMSG_STOP:
141 		break;
142 	case IMSG_CTL_SEEK:
143 		if (s == NULL)
144 			break;
145 		if (IMSG_DATA_SIZE(imsg) != sizeof(seek))
146 			fatalx("wrong size for seek ctl");
147 		memcpy(&seek, imsg.data, sizeof(seek));
148 		if (seek.percent) {
149 			*s = (double)seek.offset * (double)duration / 100.0;
150 		} else {
151 			*s = seek.offset * current_rate;
152 			if (seek.relative)
153 				*s += samples;
154 		}
155 		if (*s < 0)
156 			*s = 0;
157 		break;
158 	default:
159 		fatalx("unknown imsg %d", imsg.hdr.type);
160 	}
161 
162 	imsg_free(&imsg);
163 	return ret;
164 }
165 
166 static void
167 player_senderr(const char *errstr)
168 {
169 	size_t len = 0;
170 
171 	if (errstr != NULL)
172 		len = strlen(errstr) + 1;
173 
174 	imsg_compose(ibuf, IMSG_ERR, 0, 0, -1, errstr, len);
175 	imsg_flush(ibuf);
176 }
177 
178 static void
179 player_sendeof(void)
180 {
181 	imsg_compose(ibuf, IMSG_EOF, 0, 0, -1, NULL, 0);
182 	imsg_flush(ibuf);
183 }
184 
185 static int
186 player_playnext(const char **errstr)
187 {
188 	static char buf[512];
189 	ssize_t r;
190 	int fd = nextfd;
191 
192 	assert(nextfd != -1);
193 	nextfd = -1;
194 
195 	/* reset samples and set position to zero */
196 	samples = 0;
197 	imsg_compose(ibuf, IMSG_POS, 0, 0, -1, &samples, sizeof(samples));
198 	imsg_flush(ibuf);
199 
200 	r = read(fd, buf, sizeof(buf));
201 
202 	/* 8 byte is the larger magic number */
203 	if (r < 8) {
204 		*errstr = "read failed";
205 		goto err;
206 	}
207 
208 	if (lseek(fd, 0, SEEK_SET) == -1) {
209 		*errstr = "lseek failed";
210 		goto err;
211 	}
212 
213 	if (memcmp(buf, "fLaC", 4) == 0)
214 		return play_flac(fd, errstr);
215 	if (memcmp(buf, "ID3", 3) == 0 ||
216 	    memcmp(buf, "\xFF\xFB", 2) == 0)
217 		return play_mp3(fd, errstr);
218 	if (memmem(buf, r, "OpusHead", 8) != NULL)
219 		return play_opus(fd, errstr);
220 	if (memmem(buf, r, "OggS", 4) != NULL)
221 		return play_oggvorbis(fd, errstr);
222 
223 	*errstr = "unknown file type";
224 err:
225 	close(fd);
226 	return -1;
227 }
228 
229 static int
230 player_pause(int64_t *s)
231 {
232 	int r;
233 
234 	r = player_dispatch(s, 1);
235 	return r == IMSG_RESUME || r == IMSG_CTL_SEEK;
236 }
237 
238 static int
239 player_shouldstop(int64_t *s, int wait)
240 {
241 	switch (player_dispatch(s, wait)) {
242 	case IMSG_PAUSE:
243 		if (player_pause(s))
244 			break;
245 		/* fallthrough */
246 	case IMSG_STOP:
247 		return 1;
248 	}
249 
250 	return 0;
251 }
252 
253 int
254 play(const void *buf, size_t len, int64_t *s)
255 {
256 	size_t w;
257 	int revents, r, wait;
258 
259 	*s = -1;
260 	while (len != 0) {
261 		audio_pollfd(player_pfds + 1, player_nfds, POLLOUT);
262 		r = poll(player_pfds, player_nfds + 1, INFTIM);
263 		if (r == -1)
264 			fatal("poll");
265 
266 		wait = player_pfds[0].revents & (POLLHUP|POLLIN);
267 		if (player_shouldstop(s, wait)) {
268 			audio_flush();
269 			return 0;
270 		}
271 
272 		revents = audio_revents(player_pfds + 1, player_nfds);
273 		if (revents & POLLHUP) {
274 			if (errno == EAGAIN)
275 				continue;
276 			fatal("audio hang-up");
277 		}
278 		if (revents & POLLOUT) {
279 			w = audio_write(buf, len);
280 			len -= w;
281 			buf += w;
282 		}
283 	}
284 
285 	return 1;
286 }
287 
288 int
289 player(int debug, int verbose)
290 {
291 	int r;
292 
293 	log_init(debug, LOG_DAEMON);
294 	log_setverbose(verbose);
295 
296 	setproctitle("player");
297 	log_procinit("player");
298 
299 #if 0
300 	{
301 		static int attached;
302 
303 		while (!attached)
304 			sleep(1);
305 	}
306 #endif
307 
308 	if (audio_open(player_onmove) == -1)
309 		fatal("audio_open");
310 
311 	if ((player_nfds = audio_nfds()) <= 0)
312 		fatal("audio_nfds: invalid number of file descriptors: %d",
313 		    player_nfds);
314 
315 	/* allocate one extra for imsg */
316 	player_pfds = calloc(player_nfds + 1, sizeof(*player_pfds));
317 	if (player_pfds == NULL)
318 		fatal("calloc");
319 
320 	player_pfds[0].events = POLLIN;
321 	player_pfds[0].fd = 3;
322 
323 	ibuf = xmalloc(sizeof(*ibuf));
324 	imsg_init(ibuf, 3);
325 
326 	signal(SIGINT, player_signal_handler);
327 	signal(SIGTERM, player_signal_handler);
328 
329 	signal(SIGHUP, SIG_IGN);
330 	signal(SIGPIPE, SIG_IGN);
331 
332 	if (pledge("stdio recvfd audio", NULL) == -1)
333 		fatal("pledge");
334 
335 	while (!halted) {
336 		const char *errstr = NULL;
337 
338 		while (nextfd == -1)
339 			player_dispatch(NULL, 1);
340 
341 		r = player_playnext(&errstr);
342 		if (r == -1)
343 			player_senderr(errstr);
344 		if (r == 0)
345 			player_sendeof();
346 	}
347 
348 	return 0;
349 }