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 <alsa/asoundlib.h>
20 
21 #include <limits.h>
22 
23 #include "amused.h"
24 #include "log.h"
25 
26 static snd_pcm_t	*pcm;
27 
28 int
29 audio_open(void (*onmove_cb)(void *, int))
30 {
31 	const char	*device = "default";
32 	int		 err;
33 
34 	err = snd_pcm_open(&pcm, device, SND_PCM_STREAM_PLAYBACK,
35 	    SND_PCM_NONBLOCK);
36 	if (err < 0) {
37 		log_warnx("playback open error: %s", snd_strerror(err));
38 		return -1;
39 	}
40 
41 	/* TODO: set up onmove callback? */
42 	return 0;
43 }
44 
45 int
46 audio_setup(unsigned int bits, unsigned int rate, unsigned int channels,
47     struct pollfd *pfds)
48 {
49 	int			 err;
50 	snd_pcm_format_t	 fmt;
51 
52 	if (bits == 8)
53 		fmt = SND_PCM_FORMAT_S8;
54 	else if (bits == 16)
55 		fmt = SND_PCM_FORMAT_S16;
56 	else if (bits == 24)
57 		fmt = SND_PCM_FORMAT_S24;
58 	else if (bits == 32)
59 		fmt = SND_PCM_FORMAT_S32;
60 	else {
61 		log_warnx("can't handle %d bits", bits);
62 		return -1;
63 	}
64 
65 	err = snd_pcm_set_params(pcm, fmt, SND_PCM_ACCESS_RW_INTERLEAVED,
66 	    channels, rate, 1, 500000 /* 0.5s */);
67 	if (err < 0) {
68 		log_warnx("invalid params: %s", snd_strerror(err));
69 		return -1;
70 	}
71 
72 	err = snd_pcm_prepare(pcm);
73 	if (err < 0) {
74 		log_warnx("snd_pcm_prepare failed: %s", snd_strerror(err));
75 		return -1;
76 	}
77 
78 	return 0;
79 }
80 
81 int
82 audio_nfds(void)
83 {
84 	return snd_pcm_poll_descriptors_count(pcm);
85 }
86 
87 int
88 audio_pollfd(struct pollfd *pfds, int events)
89 {
90 	return snd_pcm_poll_descriptors(pcm, pfds, audio_nfds());
91 }
92 
93 int
94 audio_revents(struct pollfd *pfds)
95 {
96 	int			 err;
97 	unsigned short		 revents;
98 
99 	err = snd_pcm_poll_descriptors_revents(pcm, pfds, audio_nfds(),
100 	    &revents);
101 	if (err < 0) {
102 		log_warnx("snd revents failure: %s", snd_strerror(err));
103 		return 0;
104 	}
105 
106 	return revents;
107 }
108 
109 size_t
110 audio_write(const void *buf, size_t len)
111 {
112 	snd_pcm_sframes_t	ret;
113 
114 	ret = snd_pcm_writei(pcm, buf, len);
115 	if (ret < 0) {
116 		log_warnx("snd_pcm_writei failed: %s", snd_strerror(ret));
117 		return 0;
118 	}
119 	return ret;
120 }
121 
122 int
123 audio_flush(void)
124 {
125 	int			err;
126 
127 	err = snd_pcm_drop(pcm);
128 	if (err < 0) {
129 		log_warnx("snd_pcm_drop: %s", snd_strerror(err));
130 		return -1;
131 	}
132 
133 	return 0;
134 }
135 
136 int
137 audio_stop(void)
138 {
139 	int			err;
140 
141 	err = snd_pcm_drain(pcm);
142 	if (err < 0) {
143 		log_warnx("snd_pcm_drain: %s", snd_strerror(err));
144 		return -1;
145 	}
146 
147 	return 0;
148 }