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1c3f1e73 | 1 | /* |
2 | * This file is part of DisOrder | |
3 | * Copyright (C) 2005, 2006, 2007 Richard Kettlewell | |
4 | * | |
e7eb3a27 | 5 | * This program is free software: you can redistribute it and/or modify |
1c3f1e73 | 6 | * it under the terms of the GNU General Public License as published by |
e7eb3a27 | 7 | * the Free Software Foundation, either version 3 of the License, or |
1c3f1e73 | 8 | * (at your option) any later version. |
9 | * | |
e7eb3a27 RK |
10 | * This program is distributed in the hope that it will be useful, |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
1c3f1e73 | 15 | * You should have received a copy of the GNU General Public License |
e7eb3a27 | 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
1c3f1e73 | 17 | */ |
18 | /** @file server/speaker-alsa.c | |
19 | * @brief Support for @ref BACKEND_ALSA */ | |
20 | ||
05b75f8d | 21 | #include "common.h" |
1c3f1e73 | 22 | |
146e86fb | 23 | #if HAVE_ALSA_ASOUNDLIB_H |
1c3f1e73 | 24 | |
1c3f1e73 | 25 | #include <unistd.h> |
26 | #include <poll.h> | |
27 | #include <alsa/asoundlib.h> | |
28 | ||
29 | #include "configuration.h" | |
30 | #include "syscalls.h" | |
31 | #include "log.h" | |
32 | #include "speaker-protocol.h" | |
33 | #include "speaker.h" | |
34 | ||
35 | /** @brief The current PCM handle */ | |
36 | static snd_pcm_t *pcm; | |
37 | ||
38 | /** @brief Last seen buffer size */ | |
39 | static snd_pcm_uframes_t last_pcm_bufsize; | |
40 | ||
41 | /** @brief ALSA backend initialization */ | |
42 | static void alsa_init(void) { | |
43 | info("selected ALSA backend"); | |
44 | } | |
45 | ||
46 | /** @brief Log ALSA parameters */ | |
47 | static void log_params(snd_pcm_hw_params_t *hwparams, | |
48 | snd_pcm_sw_params_t *swparams) { | |
49 | snd_pcm_uframes_t f; | |
1c3f1e73 | 50 | |
51 | return; /* too verbose */ | |
52 | if(hwparams) { | |
53 | /* TODO */ | |
54 | } | |
55 | if(swparams) { | |
56 | snd_pcm_sw_params_get_silence_size(swparams, &f); | |
57 | info("sw silence_size=%lu", (unsigned long)f); | |
58 | snd_pcm_sw_params_get_silence_threshold(swparams, &f); | |
59 | info("sw silence_threshold=%lu", (unsigned long)f); | |
cf7ca906 | 60 | #if HAVE_SND_PCM_SW_PARAMS_GET_SLEEP_MIN |
b92db141 RK |
61 | { |
62 | unsigned u; | |
63 | ||
64 | snd_pcm_sw_params_get_sleep_min(swparams, &u); | |
65 | info("sw sleep_min=%lu", (unsigned long)u); | |
66 | } | |
cf7ca906 | 67 | #endif |
1c3f1e73 | 68 | snd_pcm_sw_params_get_start_threshold(swparams, &f); |
69 | info("sw start_threshold=%lu", (unsigned long)f); | |
70 | snd_pcm_sw_params_get_stop_threshold(swparams, &f); | |
71 | info("sw stop_threshold=%lu", (unsigned long)f); | |
cf7ca906 | 72 | #if HAVE_SND_PCM_SW_PARAMS_GET_XFER_ALIGN |
1c3f1e73 | 73 | snd_pcm_sw_params_get_xfer_align(swparams, &f); |
74 | info("sw xfer_align=%lu", (unsigned long)f); | |
cf7ca906 | 75 | #endif |
1c3f1e73 | 76 | } |
77 | } | |
78 | ||
79 | /** @brief ALSA deactivation */ | |
80 | static void alsa_deactivate(void) { | |
81 | if(pcm) { | |
82 | int err; | |
83 | ||
84 | if((err = snd_pcm_nonblock(pcm, 0)) < 0) | |
85 | fatal(0, "error calling snd_pcm_nonblock: %d", err); | |
86 | D(("draining pcm")); | |
87 | snd_pcm_drain(pcm); | |
88 | D(("closing pcm")); | |
89 | snd_pcm_close(pcm); | |
90 | pcm = 0; | |
91 | device_state = device_closed; | |
92 | D(("released audio device")); | |
93 | } | |
94 | } | |
95 | ||
96 | /** @brief ALSA backend activation */ | |
97 | static void alsa_activate(void) { | |
1c3f1e73 | 98 | if(!pcm) { |
99 | snd_pcm_hw_params_t *hwparams; | |
100 | snd_pcm_sw_params_t *swparams; | |
101 | snd_pcm_uframes_t pcm_bufsize; | |
102 | int err; | |
103 | int sample_format = 0; | |
104 | unsigned rate; | |
105 | ||
106 | D(("snd_pcm_open")); | |
107 | if((err = snd_pcm_open(&pcm, | |
108 | config->device, | |
109 | SND_PCM_STREAM_PLAYBACK, | |
110 | SND_PCM_NONBLOCK))) { | |
111 | error(0, "error from snd_pcm_open: %d", err); | |
112 | goto error; | |
113 | } | |
114 | snd_pcm_hw_params_alloca(&hwparams); | |
115 | D(("set up hw params")); | |
116 | if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0) | |
117 | fatal(0, "error from snd_pcm_hw_params_any: %d", err); | |
118 | if((err = snd_pcm_hw_params_set_access(pcm, hwparams, | |
119 | SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) | |
120 | fatal(0, "error from snd_pcm_hw_params_set_access: %d", err); | |
6d2d327c | 121 | switch(config->sample_format.bits) { |
1c3f1e73 | 122 | case 8: |
123 | sample_format = SND_PCM_FORMAT_S8; | |
124 | break; | |
125 | case 16: | |
6d2d327c RK |
126 | switch(config->sample_format.endian) { |
127 | case ENDIAN_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break; | |
128 | case ENDIAN_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break; | |
129 | default: | |
130 | error(0, "unrecognized byte format %d", config->sample_format.endian); | |
1c3f1e73 | 131 | goto fatal; |
132 | } | |
133 | break; | |
134 | default: | |
6d2d327c | 135 | error(0, "unsupported sample size %d", config->sample_format.bits); |
1c3f1e73 | 136 | goto fatal; |
137 | } | |
138 | if((err = snd_pcm_hw_params_set_format(pcm, hwparams, | |
139 | sample_format)) < 0) { | |
140 | error(0, "error from snd_pcm_hw_params_set_format (%d): %d", | |
141 | sample_format, err); | |
142 | goto fatal; | |
143 | } | |
6d2d327c | 144 | rate = config->sample_format.rate; |
1c3f1e73 | 145 | if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) { |
146 | error(0, "error from snd_pcm_hw_params_set_rate (%d): %d", | |
6d2d327c | 147 | config->sample_format.rate, err); |
1c3f1e73 | 148 | goto fatal; |
149 | } | |
6d2d327c RK |
150 | if(rate != (unsigned)config->sample_format.rate) |
151 | info("want rate %d, got %u", config->sample_format.rate, rate); | |
152 | if((err = snd_pcm_hw_params_set_channels | |
153 | (pcm, hwparams, config->sample_format.channels)) < 0) { | |
1c3f1e73 | 154 | error(0, "error from snd_pcm_hw_params_set_channels (%d): %d", |
6d2d327c | 155 | config->sample_format.channels, err); |
1c3f1e73 | 156 | goto fatal; |
157 | } | |
158 | pcm_bufsize = 3 * FRAMES; | |
159 | if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, | |
160 | &pcm_bufsize)) < 0) | |
161 | fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d", | |
162 | 3 * FRAMES, err); | |
163 | if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize) | |
164 | info("asked for PCM buffer of %d frames, got %d", | |
165 | 3 * FRAMES, (int)pcm_bufsize); | |
166 | last_pcm_bufsize = pcm_bufsize; | |
167 | if((err = snd_pcm_hw_params(pcm, hwparams)) < 0) | |
168 | fatal(0, "error calling snd_pcm_hw_params: %d", err); | |
169 | D(("set up sw params")); | |
170 | snd_pcm_sw_params_alloca(&swparams); | |
171 | if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0) | |
172 | fatal(0, "error calling snd_pcm_sw_params_current: %d", err); | |
173 | if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0) | |
174 | fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d", | |
175 | FRAMES, err); | |
176 | if((err = snd_pcm_sw_params(pcm, swparams)) < 0) | |
177 | fatal(0, "error calling snd_pcm_sw_params: %d", err); | |
1c3f1e73 | 178 | D(("acquired audio device")); |
179 | log_params(hwparams, swparams); | |
180 | device_state = device_open; | |
181 | } | |
182 | return; | |
183 | fatal: | |
184 | abandon(); | |
185 | error: | |
186 | /* We assume the error is temporary and that we'll retry in a bit. */ | |
187 | if(pcm) { | |
188 | snd_pcm_close(pcm); | |
189 | pcm = 0; | |
190 | device_state = device_error; | |
191 | } | |
192 | return; | |
193 | } | |
194 | ||
195 | /** @brief Play via ALSA */ | |
196 | static size_t alsa_play(size_t frames) { | |
197 | snd_pcm_sframes_t pcm_written_frames; | |
198 | int err; | |
199 | ||
200 | pcm_written_frames = snd_pcm_writei(pcm, | |
201 | playing->buffer + playing->start, | |
202 | frames); | |
203 | D(("actually play %zu frames, wrote %d", | |
204 | frames, (int)pcm_written_frames)); | |
205 | if(pcm_written_frames < 0) { | |
206 | switch(pcm_written_frames) { | |
207 | case -EPIPE: /* underrun */ | |
208 | error(0, "snd_pcm_writei reports underrun"); | |
209 | if((err = snd_pcm_prepare(pcm)) < 0) | |
210 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
211 | return 0; | |
212 | case -EAGAIN: | |
213 | return 0; | |
214 | default: | |
215 | fatal(0, "error calling snd_pcm_writei: %d", | |
216 | (int)pcm_written_frames); | |
217 | } | |
218 | } else | |
219 | return pcm_written_frames; | |
220 | } | |
221 | ||
222 | static int alsa_slots, alsa_nslots = -1; | |
223 | ||
224 | /** @brief Fill in poll fd array for ALSA */ | |
e84fb5f0 | 225 | static void alsa_beforepoll(int attribute((unused)) *timeoutp) { |
1c3f1e73 | 226 | /* We send sample data to ALSA as fast as it can accept it, relying on |
227 | * the fact that it has a relatively small buffer to minimize pause | |
228 | * latency. */ | |
229 | int retry = 3, err; | |
230 | ||
231 | alsa_slots = fdno; | |
232 | do { | |
233 | retry = 0; | |
234 | alsa_nslots = snd_pcm_poll_descriptors(pcm, &fds[fdno], NFDS - fdno); | |
235 | if((alsa_nslots <= 0 | |
236 | || !(fds[alsa_slots].events & POLLOUT)) | |
237 | && snd_pcm_state(pcm) == SND_PCM_STATE_XRUN) { | |
238 | error(0, "underrun detected after call to snd_pcm_poll_descriptors()"); | |
239 | if((err = snd_pcm_prepare(pcm))) | |
240 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
241 | } else | |
242 | break; | |
243 | } while(retry-- > 0); | |
244 | if(alsa_nslots >= 0) | |
245 | fdno += alsa_nslots; | |
246 | } | |
247 | ||
248 | /** @brief Process poll() results for ALSA */ | |
249 | static int alsa_ready(void) { | |
250 | int err; | |
251 | ||
252 | unsigned short alsa_revents; | |
253 | ||
254 | if((err = snd_pcm_poll_descriptors_revents(pcm, | |
255 | &fds[alsa_slots], | |
256 | alsa_nslots, | |
257 | &alsa_revents)) < 0) | |
258 | fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err); | |
259 | if(alsa_revents & (POLLOUT | POLLERR)) | |
260 | return 1; | |
261 | else | |
262 | return 0; | |
263 | } | |
264 | ||
265 | const struct speaker_backend alsa_backend = { | |
266 | BACKEND_ALSA, | |
267 | 0, | |
268 | alsa_init, | |
269 | alsa_activate, | |
270 | alsa_play, | |
271 | alsa_deactivate, | |
272 | alsa_beforepoll, | |
273 | alsa_ready | |
274 | }; | |
275 | ||
276 | #endif | |
277 | ||
278 | /* | |
279 | Local Variables: | |
280 | c-basic-offset:2 | |
281 | comment-column:40 | |
282 | fill-column:79 | |
283 | indent-tabs-mode:nil | |
284 | End: | |
285 | */ |