1 /*
2  * Copyright (c) 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 <sys/socket.h>
20 
21 #include <ao/ao.h>
22 #include <limits.h>
23 #include <poll.h>
24 #include <pthread.h>
25 #include <string.h>
26 
27 #include "amused.h"
28 #include "log.h"
29 
30 static void		(*onmove_cb)(void *, int);
31 static int		 sp[2]; /* main, audio thread */
32 static pthread_t	 at;
33 
34 static int		 bpf;
35 static ao_sample_format	 fmt;
36 static char		 buf[BUFSIZ];
37 static size_t		 buflen;
38 
39 static void *
40 aworker(void *d)
41 {
42 	ao_sample_format f;
43 	ao_device	*device = NULL;
44 	ssize_t		 r;
45 	int		 sock = sp[1];
46 	char		 ch;
47 
48 	memset(&f, 0, sizeof(f));
49 
50 	log_info("%s: starting", __func__);
51 
52 	for (;;) {
53 		ch = 1;
54 		if ((r = write(sock, &ch, 1)) == -1)
55 			fatal("write");
56 		if (r == 0)
57 			break;
58 
59 		if ((r = read(sock, &ch, 1)) == -1)
60 			fatal("read");
61 		if (r == 0)
62 			break;
63 
64 		if (memcmp(&fmt, &f, sizeof(f)) != 0) {
65 			if (device != NULL)
66 				ao_close(device);
67 			device = ao_open_live(ao_default_driver_id(),
68 			    &fmt, NULL);
69 			if (device == NULL) {
70 				switch (errno) {
71 				case AO_ENODRIVER:
72 					log_warnx("ao: no driver found");
73 					break;
74 				case AO_ENOTLIVE:
75 					log_warnx("ao: not a live device");
76 					break;
77 				case AO_EBADOPTION:
78 					log_warnx("ao: bad option(s)");
79 					break;
80 				case AO_EOPENDEVICE:
81 					log_warnx("ao: failed to open device");
82 					break;
83 				case AO_EFAIL:
84 				default:
85 					log_warnx("ao: failed opening driver");
86 					break;
87 				}
88 				errno = EINVAL;
89 				break;
90 			}
91 			log_info("%s: device (re)opened", __func__);
92 			memcpy(&f, &fmt, sizeof(f));
93 		}
94 
95 		if (ao_play(device, buf, buflen) == 0) {
96 			log_warnx("ao_play failed");
97 			break;
98 		}
99 	}
100 
101 	log_info("quitting audio thread");
102 	close(sock);
103 	return NULL;
104 }
105 
106 int
107 audio_open(void (*cb)(void *, int))
108 {
109 	ao_initialize();
110 	onmove_cb = cb;
111 
112 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) == -1) {
113 		log_warn("socketpair");
114 		return (-1);
115 	}
116 
117 	if (pthread_create(&at, NULL, aworker, NULL) == -1) {
118 		log_warn("pthread_create");
119 		return (-1);
120 	}
121 
122 	return 0;
123 }
124 
125 int
126 audio_setup(unsigned int bits, unsigned int rate, unsigned int channels,
127     struct pollfd *pfds, int nfds)
128 {
129 	fmt.bits = bits;
130 	fmt.rate = rate;
131 	fmt.channels = channels;
132 	fmt.byte_format = AO_FMT_NATIVE;
133 	fmt.matrix = NULL;
134 
135 	if (bits == 8)
136 		bpf = 1;
137 	else if (bits == 16)
138 		bpf = 2;
139 	else if (bits == 24 || bits == 32)
140 		bpf = 4;
141 	else {
142 		log_warnx("can't handle %d bits", bits);
143 		return -1;
144 	}
145 
146 	return 0;
147 }
148 
149 int
150 audio_nfds(void)
151 {
152 	return 1;
153 }
154 
155 int
156 audio_pollfd(struct pollfd *pfds, int nfds, int events)
157 {
158 	if (nfds != 1) {
159 		errno = EINVAL;
160 		return -1;
161 	}
162 
163 	pfds[0].fd = sp[0];
164 	pfds[0].events = POLLIN;
165 	return 0;
166 }
167 
168 int
169 audio_revents(struct pollfd *pfds, int nfds)
170 {
171 	if (nfds != 1) {
172 		log_warnx("%s: called with nfds=%d", __func__, nfds);
173 		return 0;
174 	}
175 
176 	/* don't need to check; if we're here the audio thread is ready */
177 	return POLLOUT;
178 }
179 
180 size_t
181 audio_write(const void *data, size_t len)
182 {
183 	char	 ch;
184 	ssize_t	 r;
185 
186 	if ((r = read(sp[0], &ch, 1)) == -1) {
187 		log_warn("ao/%s: read failed", __func__);
188 		return 0;
189 	}
190 	if (r == 0)
191 		return 0;
192 
193 	if (len > sizeof(buf))
194 		len = sizeof(buf);
195 
196 	memcpy(buf, data, len);
197 	buflen = len;
198 
199 	ch = 1;
200 	if ((r = write(sp[0], &ch, 1)) == -1) {
201 		log_warn("ao/%s: write failed", __func__);
202 		return 0;
203 	}
204 	if (r == 0) {
205 		log_warnx("ao/%s: write got EOF", __func__);
206 		return 0;
207 	}
208 
209 	if (onmove_cb)
210 		onmove_cb(NULL, len / bpf);
211 
212 	return len;
213 }
214 
215 int
216 audio_flush(void)
217 {
218 	return 0;
219 }
220 
221 int
222 audio_stop(void)
223 {
224 	return 0;
225 }