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1c3f1e73 | 1 | /* |
2 | * This file is part of DisOrder | |
3 | * Copyright (C) 2005, 2006, 2007 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
20 | /** @file server/speaker-alsa.c | |
21 | * @brief Support for @ref BACKEND_ALSA */ | |
22 | ||
23 | #include <config.h> | |
24 | ||
146e86fb | 25 | #if HAVE_ALSA_ASOUNDLIB_H |
1c3f1e73 | 26 | |
27 | #include "types.h" | |
28 | ||
29 | #include <unistd.h> | |
30 | #include <poll.h> | |
31 | #include <alsa/asoundlib.h> | |
32 | ||
33 | #include "configuration.h" | |
34 | #include "syscalls.h" | |
35 | #include "log.h" | |
36 | #include "speaker-protocol.h" | |
37 | #include "speaker.h" | |
38 | ||
39 | /** @brief The current PCM handle */ | |
40 | static snd_pcm_t *pcm; | |
41 | ||
42 | /** @brief Last seen buffer size */ | |
43 | static snd_pcm_uframes_t last_pcm_bufsize; | |
44 | ||
45 | /** @brief ALSA backend initialization */ | |
46 | static void alsa_init(void) { | |
47 | info("selected ALSA backend"); | |
48 | } | |
49 | ||
50 | /** @brief Log ALSA parameters */ | |
51 | static void log_params(snd_pcm_hw_params_t *hwparams, | |
52 | snd_pcm_sw_params_t *swparams) { | |
53 | snd_pcm_uframes_t f; | |
54 | unsigned u; | |
55 | ||
56 | return; /* too verbose */ | |
57 | if(hwparams) { | |
58 | /* TODO */ | |
59 | } | |
60 | if(swparams) { | |
61 | snd_pcm_sw_params_get_silence_size(swparams, &f); | |
62 | info("sw silence_size=%lu", (unsigned long)f); | |
63 | snd_pcm_sw_params_get_silence_threshold(swparams, &f); | |
64 | info("sw silence_threshold=%lu", (unsigned long)f); | |
65 | snd_pcm_sw_params_get_sleep_min(swparams, &u); | |
66 | info("sw sleep_min=%lu", (unsigned long)u); | |
67 | snd_pcm_sw_params_get_start_threshold(swparams, &f); | |
68 | info("sw start_threshold=%lu", (unsigned long)f); | |
69 | snd_pcm_sw_params_get_stop_threshold(swparams, &f); | |
70 | info("sw stop_threshold=%lu", (unsigned long)f); | |
71 | snd_pcm_sw_params_get_xfer_align(swparams, &f); | |
72 | info("sw xfer_align=%lu", (unsigned long)f); | |
73 | } | |
74 | } | |
75 | ||
76 | /** @brief ALSA deactivation */ | |
77 | static void alsa_deactivate(void) { | |
78 | if(pcm) { | |
79 | int err; | |
80 | ||
81 | if((err = snd_pcm_nonblock(pcm, 0)) < 0) | |
82 | fatal(0, "error calling snd_pcm_nonblock: %d", err); | |
83 | D(("draining pcm")); | |
84 | snd_pcm_drain(pcm); | |
85 | D(("closing pcm")); | |
86 | snd_pcm_close(pcm); | |
87 | pcm = 0; | |
88 | device_state = device_closed; | |
89 | D(("released audio device")); | |
90 | } | |
91 | } | |
92 | ||
93 | /** @brief ALSA backend activation */ | |
94 | static void alsa_activate(void) { | |
1c3f1e73 | 95 | if(!pcm) { |
96 | snd_pcm_hw_params_t *hwparams; | |
97 | snd_pcm_sw_params_t *swparams; | |
98 | snd_pcm_uframes_t pcm_bufsize; | |
99 | int err; | |
100 | int sample_format = 0; | |
101 | unsigned rate; | |
102 | ||
103 | D(("snd_pcm_open")); | |
104 | if((err = snd_pcm_open(&pcm, | |
105 | config->device, | |
106 | SND_PCM_STREAM_PLAYBACK, | |
107 | SND_PCM_NONBLOCK))) { | |
108 | error(0, "error from snd_pcm_open: %d", err); | |
109 | goto error; | |
110 | } | |
111 | snd_pcm_hw_params_alloca(&hwparams); | |
112 | D(("set up hw params")); | |
113 | if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0) | |
114 | fatal(0, "error from snd_pcm_hw_params_any: %d", err); | |
115 | if((err = snd_pcm_hw_params_set_access(pcm, hwparams, | |
116 | SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) | |
117 | fatal(0, "error from snd_pcm_hw_params_set_access: %d", err); | |
6d2d327c | 118 | switch(config->sample_format.bits) { |
1c3f1e73 | 119 | case 8: |
120 | sample_format = SND_PCM_FORMAT_S8; | |
121 | break; | |
122 | case 16: | |
6d2d327c RK |
123 | switch(config->sample_format.endian) { |
124 | case ENDIAN_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break; | |
125 | case ENDIAN_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break; | |
126 | default: | |
127 | error(0, "unrecognized byte format %d", config->sample_format.endian); | |
1c3f1e73 | 128 | goto fatal; |
129 | } | |
130 | break; | |
131 | default: | |
6d2d327c | 132 | error(0, "unsupported sample size %d", config->sample_format.bits); |
1c3f1e73 | 133 | goto fatal; |
134 | } | |
135 | if((err = snd_pcm_hw_params_set_format(pcm, hwparams, | |
136 | sample_format)) < 0) { | |
137 | error(0, "error from snd_pcm_hw_params_set_format (%d): %d", | |
138 | sample_format, err); | |
139 | goto fatal; | |
140 | } | |
6d2d327c | 141 | rate = config->sample_format.rate; |
1c3f1e73 | 142 | if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) { |
143 | error(0, "error from snd_pcm_hw_params_set_rate (%d): %d", | |
6d2d327c | 144 | config->sample_format.rate, err); |
1c3f1e73 | 145 | goto fatal; |
146 | } | |
6d2d327c RK |
147 | if(rate != (unsigned)config->sample_format.rate) |
148 | info("want rate %d, got %u", config->sample_format.rate, rate); | |
149 | if((err = snd_pcm_hw_params_set_channels | |
150 | (pcm, hwparams, config->sample_format.channels)) < 0) { | |
1c3f1e73 | 151 | error(0, "error from snd_pcm_hw_params_set_channels (%d): %d", |
6d2d327c | 152 | config->sample_format.channels, err); |
1c3f1e73 | 153 | goto fatal; |
154 | } | |
155 | pcm_bufsize = 3 * FRAMES; | |
156 | if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, | |
157 | &pcm_bufsize)) < 0) | |
158 | fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d", | |
159 | 3 * FRAMES, err); | |
160 | if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize) | |
161 | info("asked for PCM buffer of %d frames, got %d", | |
162 | 3 * FRAMES, (int)pcm_bufsize); | |
163 | last_pcm_bufsize = pcm_bufsize; | |
164 | if((err = snd_pcm_hw_params(pcm, hwparams)) < 0) | |
165 | fatal(0, "error calling snd_pcm_hw_params: %d", err); | |
166 | D(("set up sw params")); | |
167 | snd_pcm_sw_params_alloca(&swparams); | |
168 | if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0) | |
169 | fatal(0, "error calling snd_pcm_sw_params_current: %d", err); | |
170 | if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0) | |
171 | fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d", | |
172 | FRAMES, err); | |
173 | if((err = snd_pcm_sw_params(pcm, swparams)) < 0) | |
174 | fatal(0, "error calling snd_pcm_sw_params: %d", err); | |
1c3f1e73 | 175 | D(("acquired audio device")); |
176 | log_params(hwparams, swparams); | |
177 | device_state = device_open; | |
178 | } | |
179 | return; | |
180 | fatal: | |
181 | abandon(); | |
182 | error: | |
183 | /* We assume the error is temporary and that we'll retry in a bit. */ | |
184 | if(pcm) { | |
185 | snd_pcm_close(pcm); | |
186 | pcm = 0; | |
187 | device_state = device_error; | |
188 | } | |
189 | return; | |
190 | } | |
191 | ||
192 | /** @brief Play via ALSA */ | |
193 | static size_t alsa_play(size_t frames) { | |
194 | snd_pcm_sframes_t pcm_written_frames; | |
195 | int err; | |
196 | ||
197 | pcm_written_frames = snd_pcm_writei(pcm, | |
198 | playing->buffer + playing->start, | |
199 | frames); | |
200 | D(("actually play %zu frames, wrote %d", | |
201 | frames, (int)pcm_written_frames)); | |
202 | if(pcm_written_frames < 0) { | |
203 | switch(pcm_written_frames) { | |
204 | case -EPIPE: /* underrun */ | |
205 | error(0, "snd_pcm_writei reports underrun"); | |
206 | if((err = snd_pcm_prepare(pcm)) < 0) | |
207 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
208 | return 0; | |
209 | case -EAGAIN: | |
210 | return 0; | |
211 | default: | |
212 | fatal(0, "error calling snd_pcm_writei: %d", | |
213 | (int)pcm_written_frames); | |
214 | } | |
215 | } else | |
216 | return pcm_written_frames; | |
217 | } | |
218 | ||
219 | static int alsa_slots, alsa_nslots = -1; | |
220 | ||
221 | /** @brief Fill in poll fd array for ALSA */ | |
e84fb5f0 | 222 | static void alsa_beforepoll(int attribute((unused)) *timeoutp) { |
1c3f1e73 | 223 | /* We send sample data to ALSA as fast as it can accept it, relying on |
224 | * the fact that it has a relatively small buffer to minimize pause | |
225 | * latency. */ | |
226 | int retry = 3, err; | |
227 | ||
228 | alsa_slots = fdno; | |
229 | do { | |
230 | retry = 0; | |
231 | alsa_nslots = snd_pcm_poll_descriptors(pcm, &fds[fdno], NFDS - fdno); | |
232 | if((alsa_nslots <= 0 | |
233 | || !(fds[alsa_slots].events & POLLOUT)) | |
234 | && snd_pcm_state(pcm) == SND_PCM_STATE_XRUN) { | |
235 | error(0, "underrun detected after call to snd_pcm_poll_descriptors()"); | |
236 | if((err = snd_pcm_prepare(pcm))) | |
237 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
238 | } else | |
239 | break; | |
240 | } while(retry-- > 0); | |
241 | if(alsa_nslots >= 0) | |
242 | fdno += alsa_nslots; | |
243 | } | |
244 | ||
245 | /** @brief Process poll() results for ALSA */ | |
246 | static int alsa_ready(void) { | |
247 | int err; | |
248 | ||
249 | unsigned short alsa_revents; | |
250 | ||
251 | if((err = snd_pcm_poll_descriptors_revents(pcm, | |
252 | &fds[alsa_slots], | |
253 | alsa_nslots, | |
254 | &alsa_revents)) < 0) | |
255 | fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err); | |
256 | if(alsa_revents & (POLLOUT | POLLERR)) | |
257 | return 1; | |
258 | else | |
259 | return 0; | |
260 | } | |
261 | ||
262 | const struct speaker_backend alsa_backend = { | |
263 | BACKEND_ALSA, | |
264 | 0, | |
265 | alsa_init, | |
266 | alsa_activate, | |
267 | alsa_play, | |
268 | alsa_deactivate, | |
269 | alsa_beforepoll, | |
270 | alsa_ready | |
271 | }; | |
272 | ||
273 | #endif | |
274 | ||
275 | /* | |
276 | Local Variables: | |
277 | c-basic-offset:2 | |
278 | comment-column:40 | |
279 | fill-column:79 | |
280 | indent-tabs-mode:nil | |
281 | End: | |
282 | */ |