1 /*
2  * Copyright (c) 2022 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 static struct imsgbuf	*ibuf;
38 
39 static int nextfd = -1;
40 static int64_t samples;
41 static int64_t duration;
42 static unsigned int current_rate;
43 
44 volatile sig_atomic_t halted;
45 
46 static void
47 player_signal_handler(int signo)
48 {
49 	halted = 1;
50 }
51 
52 int
53 player_setup(unsigned int bits, unsigned int rate, unsigned int channels)
54 {
55 	log_debug("%s: bits=%u, rate=%u, channels=%u", __func__,
56 	    bits, rate, channels);
57 
58 	current_rate = rate;
59 	return audio_setup(bits, rate, channels, player_pfds + 1);
60 }
61 
62 void
63 player_setduration(int64_t d)
64 {
65 	int64_t seconds;
66 
67 	duration = d;
68 	seconds = duration / current_rate;
69 	imsg_compose(ibuf, IMSG_LEN, 0, 0, -1, &seconds, sizeof(seconds));
70 	imsg_flush(ibuf);
71 }
72 
73 static void
74 player_onmove(void *arg, int delta)
75 {
76 	static int64_t reported;
77 	int64_t sec;
78 
79 	samples += delta;
80 	if (llabs(samples - reported) >= current_rate) {
81 		reported = samples;
82 		sec = samples / current_rate;
83 
84 		imsg_compose(ibuf, IMSG_POS, 0, 0, -1, &sec, sizeof(sec));
85 		imsg_flush(ibuf);
86 	}
87 }
88 
89 void
90 player_setpos(int64_t pos)
91 {
92 	samples = pos;
93 	player_onmove(NULL, 0);
94 }
95 
96 /* process only one message */
97 static int
98 player_dispatch(int64_t *s, int wait)
99 {
100 	struct player_seek seek;
101 	struct pollfd	pfd;
102 	struct imsg	imsg;
103 	ssize_t		n;
104 	int		ret;
105 
106 	if (halted != 0)
107 		return IMSG_STOP;
108 
109 again:
110 	if ((n = imsg_get(ibuf, &imsg)) == -1)
111 		fatal("imsg_get");
112 	if (n == 0) {
113 		if (!wait)
114 			return -1;
115 
116 		pfd.fd = ibuf->fd;
117 		pfd.events = POLLIN;
118 		if (poll(&pfd, 1, INFTIM) == -1)
119 			fatal("poll");
120 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
121 			fatal("imsg_read");
122 		if (n == 0)
123 			fatalx("pipe closed");
124 		goto again;
125 	}
126 
127 	ret = imsg.hdr.type;
128 	switch (imsg.hdr.type) {
129 	case IMSG_PLAY:
130 		if (nextfd != -1)
131 			fatalx("track already enqueued");
132 		if ((nextfd = imsg.fd) == -1)
133 			fatalx("%s: got invalid file descriptor", __func__);
134 		log_debug("song enqueued");
135 		ret = IMSG_STOP;
136 		break;
137 	case IMSG_RESUME:
138 	case IMSG_PAUSE:
139 	case IMSG_STOP:
140 		break;
141 	case IMSG_CTL_SEEK:
142 		if (s == NULL)
143 			break;
144 		if (IMSG_DATA_SIZE(imsg) != sizeof(seek))
145 			fatalx("wrong size for seek ctl");
146 		memcpy(&seek, imsg.data, sizeof(seek));
147 		if (seek.percent) {
148 			*s = (double)seek.offset * (double)duration / 100.0;
149 		} else {
150 			*s = seek.offset * current_rate;
151 			if (seek.relative)
152 				*s += samples;
153 		}
154 		if (*s < 0)
155 			*s = 0;
156 		break;
157 	default:
158 		fatalx("unknown imsg %d", imsg.hdr.type);
159 	}
160 
161 	imsg_free(&imsg);
162 	return ret;
163 }
164 
165 static void
166 player_senderr(const char *errstr)
167 {
168 	size_t len = 0;
169 
170 	if (errstr != NULL)
171 		len = strlen(errstr) + 1;
172 
173 	imsg_compose(ibuf, IMSG_ERR, 0, 0, -1, errstr, len);
174 	imsg_flush(ibuf);
175 }
176 
177 static void
178 player_sendeof(void)
179 {
180 	imsg_compose(ibuf, IMSG_EOF, 0, 0, -1, NULL, 0);
181 	imsg_flush(ibuf);
182 }
183 
184 static int
185 player_playnext(const char **errstr)
186 {
187 	static char buf[512];
188 	ssize_t r;
189 	int fd = nextfd;
190 
191 	assert(nextfd != -1);
192 	nextfd = -1;
193 
194 	/* reset samples and set position to zero */
195 	samples = 0;
196 	imsg_compose(ibuf, IMSG_POS, 0, 0, -1, &samples, sizeof(samples));
197 	imsg_flush(ibuf);
198 
199 	r = read(fd, buf, sizeof(buf));
200 
201 	/* 8 byte is the larger magic number */
202 	if (r < 8) {
203 		*errstr = "read failed";
204 		goto err;
205 	}
206 
207 	if (lseek(fd, 0, SEEK_SET) == -1) {
208 		*errstr = "lseek failed";
209 		goto err;
210 	}
211 
212 	if (memcmp(buf, "fLaC", 4) == 0)
213 		return play_flac(fd, errstr);
214 	if (memcmp(buf, "ID3", 3) == 0 ||
215 	    memcmp(buf, "\xFF\xFB", 2) == 0)
216 		return play_mp3(fd, errstr);
217 	if (memmem(buf, r, "OpusHead", 8) != NULL)
218 		return play_opus(fd, errstr);
219 	if (memmem(buf, r, "OggS", 4) != NULL)
220 		return play_oggvorbis(fd, errstr);
221 
222 	*errstr = "unknown file type";
223 err:
224 	close(fd);
225 	return -1;
226 }
227 
228 static int
229 player_pause(int64_t *s)
230 {
231 	int r;
232 
233 	r = player_dispatch(s, 1);
234 	return r == IMSG_RESUME || r == IMSG_CTL_SEEK;
235 }
236 
237 static int
238 player_shouldstop(int64_t *s, int wait)
239 {
240 	switch (player_dispatch(s, wait)) {
241 	case IMSG_PAUSE:
242 		if (player_pause(s))
243 			break;
244 		/* fallthrough */
245 	case IMSG_STOP:
246 		return 1;
247 	}
248 
249 	return 0;
250 }
251 
252 int
253 play(const void *buf, size_t len, int64_t *s)
254 {
255 	size_t w;
256 	int nfds, revents, r, wait;
257 
258 	*s = -1;
259 	while (len != 0) {
260 		nfds = audio_pollfd(player_pfds + 1, POLLOUT);
261 		r = poll(player_pfds, nfds + 1, INFTIM);
262 		if (r == -1)
263 			fatal("poll");
264 
265 		wait = player_pfds[0].revents & (POLLHUP|POLLIN);
266 		if (player_shouldstop(s, wait)) {
267 			audio_flush();
268 			return 0;
269 		}
270 
271 		revents = audio_revents(player_pfds + 1);
272 		if (revents & POLLHUP) {
273 			if (errno == EAGAIN)
274 				continue;
275 			fatal("audio hang-up");
276 		}
277 		if (revents & POLLOUT) {
278 			w = audio_write(buf, len);
279 			len -= w;
280 			buf += w;
281 		}
282 	}
283 
284 	return 1;
285 }
286 
287 int
288 player(int debug, int verbose)
289 {
290 	int r;
291 
292 	log_init(debug, LOG_DAEMON);
293 	log_setverbose(verbose);
294 
295 	setproctitle("player");
296 	log_procinit("player");
297 
298 #if 0
299 	{
300 		static int attached;
301 
302 		while (!attached)
303 			sleep(1);
304 	}
305 #endif
306 
307 	if (audio_open(player_onmove) == -1)
308 		fatal("audio_open");
309 
310 	/* allocate one extra for imsg */
311 	player_pfds = calloc(audio_nfds() + 1, sizeof(*player_pfds));
312 	if (player_pfds == NULL)
313 		fatal("calloc");
314 
315 	player_pfds[0].events = POLLIN;
316 	player_pfds[0].fd = 3;
317 
318 	ibuf = xmalloc(sizeof(*ibuf));
319 	imsg_init(ibuf, 3);
320 
321 	signal(SIGINT, player_signal_handler);
322 	signal(SIGTERM, player_signal_handler);
323 
324 	signal(SIGHUP, SIG_IGN);
325 	signal(SIGPIPE, SIG_IGN);
326 
327 	if (pledge("stdio recvfd audio", NULL) == -1)
328 		fatal("pledge");
329 
330 	while (!halted) {
331 		const char *errstr = NULL;
332 
333 		while (nextfd == -1)
334 			player_dispatch(NULL, 1);
335 
336 		r = player_playnext(&errstr);
337 		if (r == -1)
338 			player_senderr(errstr);
339 		if (r == 0)
340 			player_sendeof();
341 	}
342 
343 	return 0;
344 }