Commit | Line | Data |
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32d23d03 GI |
1 | /* |
2 | * (C) notaz, 2013 | |
3 | * | |
4 | * This work is licensed under the terms of any of these licenses | |
5 | * (at your option): | |
6 | * - GNU GPL, version 2 or later. | |
7 | * - GNU LGPL, version 2.1 or later. | |
8 | * - MAME license. | |
9 | * See the COPYING file in the top-level directory. | |
10 | */ | |
11 | ||
12 | #include <stdio.h> | |
13 | #include <alsa/asoundlib.h> | |
14 | #include <unistd.h> | |
15 | ||
16 | #include "sndout_alsa.h" | |
17 | ||
18 | static snd_pcm_t *handle; | |
19 | static snd_pcm_uframes_t buffer_size, period_size; | |
20 | static unsigned int channels; | |
21 | static void *silent_period; | |
22 | ||
23 | int sndout_alsa_init(void) | |
24 | { | |
25 | int ret; | |
26 | ||
27 | ret = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0); | |
28 | if (ret != 0) | |
29 | return -1; | |
30 | ||
31 | return 0; | |
32 | } | |
33 | ||
34 | int sndout_alsa_start(int rate_, int stereo) | |
35 | { | |
36 | snd_pcm_hw_params_t *hwparams = NULL; | |
37 | unsigned int rate = rate_; | |
38 | int samples, shift; | |
39 | int ret; | |
40 | ||
41 | samples = rate * 40 / 1000; | |
42 | for (shift = 8; (1 << shift) < samples; shift++) | |
43 | ; | |
44 | period_size = 1 << shift; | |
45 | buffer_size = 8 * period_size; | |
46 | ||
47 | snd_pcm_hw_params_alloca(&hwparams); | |
48 | ||
49 | ret = snd_pcm_hw_params_any(handle, hwparams); | |
50 | ret |= snd_pcm_hw_params_set_access(handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED); | |
51 | ret |= snd_pcm_hw_params_set_format(handle, hwparams, SND_PCM_FORMAT_S16_LE); | |
52 | ret |= snd_pcm_hw_params_set_channels(handle, hwparams, stereo ? 2 : 1); | |
53 | ret |= snd_pcm_hw_params_set_rate_near(handle, hwparams, &rate, 0); | |
54 | ret |= snd_pcm_hw_params_set_buffer_size_near(handle, hwparams, &buffer_size); | |
55 | ret |= snd_pcm_hw_params_set_period_size_near(handle, hwparams, &period_size, NULL); | |
56 | ||
57 | if (ret != 0) { | |
58 | fprintf(stderr, "sndout_alsa: failed to set hwparams\n"); | |
59 | return -1; | |
60 | } | |
61 | ||
62 | ret = snd_pcm_hw_params(handle, hwparams); | |
63 | if (ret != 0) { | |
64 | fprintf(stderr, "sndout_alsa: failed to apply hwparams: %d\n", | |
65 | ret); | |
66 | return -1; | |
67 | } | |
68 | ||
69 | snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size); | |
70 | snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL); | |
71 | snd_pcm_hw_params_get_channels(hwparams, &channels); | |
72 | ||
73 | silent_period = realloc(silent_period, period_size * 2 * channels); | |
74 | if (silent_period != NULL) | |
75 | memset(silent_period, 0, period_size * 2 * channels); | |
76 | ||
77 | ret = snd_pcm_prepare(handle); | |
78 | ret |= snd_pcm_start(handle); | |
79 | ||
80 | if (ret != 0) { | |
81 | fprintf(stderr, "sndout_alsa: failed to start pcm: %d\n", | |
82 | ret); | |
83 | return -1; | |
84 | } | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | void sndout_alsa_stop(void) | |
90 | { | |
91 | // nothing? | |
92 | } | |
93 | ||
94 | void sndout_alsa_wait(void) | |
95 | { | |
96 | snd_pcm_sframes_t left; | |
97 | ||
98 | while (1) | |
99 | { | |
100 | left = snd_pcm_avail(handle); | |
101 | if (left < 0 || left >= buffer_size / 2) | |
102 | break; | |
103 | ||
104 | usleep(4000); | |
105 | } | |
106 | } | |
107 | ||
108 | int sndout_alsa_write_nb(const void *samples, int len) | |
109 | { | |
110 | snd_pcm_sframes_t left; | |
111 | int ret; | |
112 | ||
113 | len /= 2; | |
114 | if (channels == 2) | |
115 | len /= 2; | |
116 | ||
117 | left = snd_pcm_avail(handle); | |
118 | if (left >= 0 && left < len) | |
119 | return 0; | |
120 | ||
121 | ret = snd_pcm_writei(handle, samples, len); | |
122 | if (ret < 0) { | |
123 | ret = snd_pcm_recover(handle, ret, 1); | |
124 | if (ret != 0) | |
125 | fprintf(stderr, "sndout_alsa snd_pcm_recover: %d\n", ret); | |
126 | ||
127 | if (silent_period) | |
128 | snd_pcm_writei(handle, silent_period, period_size); | |
129 | snd_pcm_writei(handle, samples, len); | |
130 | } | |
131 | ||
132 | return len; | |
133 | } | |
134 | ||
135 | void sndout_alsa_exit(void) | |
136 | { | |
137 | snd_pcm_close(handle); | |
138 | handle = NULL; | |
139 | } |