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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 | ||
05b75f8d | 23 | #include "common.h" |
1c3f1e73 | 24 | |
146e86fb | 25 | #if HAVE_ALSA_ASOUNDLIB_H |
1c3f1e73 | 26 | |
1c3f1e73 | 27 | #include <unistd.h> |
28 | #include <poll.h> | |
29 | #include <alsa/asoundlib.h> | |
30 | ||
31 | #include "configuration.h" | |
32 | #include "syscalls.h" | |
33 | #include "log.h" | |
34 | #include "speaker-protocol.h" | |
35 | #include "speaker.h" | |
36 | ||
37 | /** @brief The current PCM handle */ | |
38 | static snd_pcm_t *pcm; | |
39 | ||
40 | /** @brief Last seen buffer size */ | |
41 | static snd_pcm_uframes_t last_pcm_bufsize; | |
42 | ||
43 | /** @brief ALSA backend initialization */ | |
44 | static void alsa_init(void) { | |
45 | info("selected ALSA backend"); | |
46 | } | |
47 | ||
48 | /** @brief Log ALSA parameters */ | |
49 | static void log_params(snd_pcm_hw_params_t *hwparams, | |
50 | snd_pcm_sw_params_t *swparams) { | |
51 | snd_pcm_uframes_t f; | |
1c3f1e73 | 52 | |
53 | return; /* too verbose */ | |
54 | if(hwparams) { | |
55 | /* TODO */ | |
56 | } | |
57 | if(swparams) { | |
58 | snd_pcm_sw_params_get_silence_size(swparams, &f); | |
59 | info("sw silence_size=%lu", (unsigned long)f); | |
60 | snd_pcm_sw_params_get_silence_threshold(swparams, &f); | |
61 | info("sw silence_threshold=%lu", (unsigned long)f); | |
cf7ca906 | 62 | #if HAVE_SND_PCM_SW_PARAMS_GET_SLEEP_MIN |
b92db141 RK |
63 | { |
64 | unsigned u; | |
65 | ||
66 | snd_pcm_sw_params_get_sleep_min(swparams, &u); | |
67 | info("sw sleep_min=%lu", (unsigned long)u); | |
68 | } | |
cf7ca906 | 69 | #endif |
1c3f1e73 | 70 | snd_pcm_sw_params_get_start_threshold(swparams, &f); |
71 | info("sw start_threshold=%lu", (unsigned long)f); | |
72 | snd_pcm_sw_params_get_stop_threshold(swparams, &f); | |
73 | info("sw stop_threshold=%lu", (unsigned long)f); | |
cf7ca906 | 74 | #if HAVE_SND_PCM_SW_PARAMS_GET_XFER_ALIGN |
1c3f1e73 | 75 | snd_pcm_sw_params_get_xfer_align(swparams, &f); |
76 | info("sw xfer_align=%lu", (unsigned long)f); | |
cf7ca906 | 77 | #endif |
1c3f1e73 | 78 | } |
79 | } | |
80 | ||
81 | /** @brief ALSA deactivation */ | |
82 | static void alsa_deactivate(void) { | |
83 | if(pcm) { | |
84 | int err; | |
85 | ||
86 | if((err = snd_pcm_nonblock(pcm, 0)) < 0) | |
87 | fatal(0, "error calling snd_pcm_nonblock: %d", err); | |
88 | D(("draining pcm")); | |
89 | snd_pcm_drain(pcm); | |
90 | D(("closing pcm")); | |
91 | snd_pcm_close(pcm); | |
92 | pcm = 0; | |
93 | device_state = device_closed; | |
94 | D(("released audio device")); | |
95 | } | |
96 | } | |
97 | ||
98 | /** @brief ALSA backend activation */ | |
99 | static void alsa_activate(void) { | |
1c3f1e73 | 100 | if(!pcm) { |
101 | snd_pcm_hw_params_t *hwparams; | |
102 | snd_pcm_sw_params_t *swparams; | |
103 | snd_pcm_uframes_t pcm_bufsize; | |
104 | int err; | |
105 | int sample_format = 0; | |
106 | unsigned rate; | |
107 | ||
108 | D(("snd_pcm_open")); | |
109 | if((err = snd_pcm_open(&pcm, | |
110 | config->device, | |
111 | SND_PCM_STREAM_PLAYBACK, | |
112 | SND_PCM_NONBLOCK))) { | |
113 | error(0, "error from snd_pcm_open: %d", err); | |
114 | goto error; | |
115 | } | |
116 | snd_pcm_hw_params_alloca(&hwparams); | |
117 | D(("set up hw params")); | |
118 | if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0) | |
119 | fatal(0, "error from snd_pcm_hw_params_any: %d", err); | |
120 | if((err = snd_pcm_hw_params_set_access(pcm, hwparams, | |
121 | SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) | |
122 | fatal(0, "error from snd_pcm_hw_params_set_access: %d", err); | |
6d2d327c | 123 | switch(config->sample_format.bits) { |
1c3f1e73 | 124 | case 8: |
125 | sample_format = SND_PCM_FORMAT_S8; | |
126 | break; | |
127 | case 16: | |
6d2d327c RK |
128 | switch(config->sample_format.endian) { |
129 | case ENDIAN_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break; | |
130 | case ENDIAN_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break; | |
131 | default: | |
132 | error(0, "unrecognized byte format %d", config->sample_format.endian); | |
1c3f1e73 | 133 | goto fatal; |
134 | } | |
135 | break; | |
136 | default: | |
6d2d327c | 137 | error(0, "unsupported sample size %d", config->sample_format.bits); |
1c3f1e73 | 138 | goto fatal; |
139 | } | |
140 | if((err = snd_pcm_hw_params_set_format(pcm, hwparams, | |
141 | sample_format)) < 0) { | |
142 | error(0, "error from snd_pcm_hw_params_set_format (%d): %d", | |
143 | sample_format, err); | |
144 | goto fatal; | |
145 | } | |
6d2d327c | 146 | rate = config->sample_format.rate; |
1c3f1e73 | 147 | if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) { |
148 | error(0, "error from snd_pcm_hw_params_set_rate (%d): %d", | |
6d2d327c | 149 | config->sample_format.rate, err); |
1c3f1e73 | 150 | goto fatal; |
151 | } | |
6d2d327c RK |
152 | if(rate != (unsigned)config->sample_format.rate) |
153 | info("want rate %d, got %u", config->sample_format.rate, rate); | |
154 | if((err = snd_pcm_hw_params_set_channels | |
155 | (pcm, hwparams, config->sample_format.channels)) < 0) { | |
1c3f1e73 | 156 | error(0, "error from snd_pcm_hw_params_set_channels (%d): %d", |
6d2d327c | 157 | config->sample_format.channels, err); |
1c3f1e73 | 158 | goto fatal; |
159 | } | |
160 | pcm_bufsize = 3 * FRAMES; | |
161 | if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams, | |
162 | &pcm_bufsize)) < 0) | |
163 | fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d", | |
164 | 3 * FRAMES, err); | |
165 | if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize) | |
166 | info("asked for PCM buffer of %d frames, got %d", | |
167 | 3 * FRAMES, (int)pcm_bufsize); | |
168 | last_pcm_bufsize = pcm_bufsize; | |
169 | if((err = snd_pcm_hw_params(pcm, hwparams)) < 0) | |
170 | fatal(0, "error calling snd_pcm_hw_params: %d", err); | |
171 | D(("set up sw params")); | |
172 | snd_pcm_sw_params_alloca(&swparams); | |
173 | if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0) | |
174 | fatal(0, "error calling snd_pcm_sw_params_current: %d", err); | |
175 | if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0) | |
176 | fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d", | |
177 | FRAMES, err); | |
178 | if((err = snd_pcm_sw_params(pcm, swparams)) < 0) | |
179 | fatal(0, "error calling snd_pcm_sw_params: %d", err); | |
1c3f1e73 | 180 | D(("acquired audio device")); |
181 | log_params(hwparams, swparams); | |
182 | device_state = device_open; | |
183 | } | |
184 | return; | |
185 | fatal: | |
186 | abandon(); | |
187 | error: | |
188 | /* We assume the error is temporary and that we'll retry in a bit. */ | |
189 | if(pcm) { | |
190 | snd_pcm_close(pcm); | |
191 | pcm = 0; | |
192 | device_state = device_error; | |
193 | } | |
194 | return; | |
195 | } | |
196 | ||
197 | /** @brief Play via ALSA */ | |
198 | static size_t alsa_play(size_t frames) { | |
199 | snd_pcm_sframes_t pcm_written_frames; | |
200 | int err; | |
201 | ||
202 | pcm_written_frames = snd_pcm_writei(pcm, | |
203 | playing->buffer + playing->start, | |
204 | frames); | |
205 | D(("actually play %zu frames, wrote %d", | |
206 | frames, (int)pcm_written_frames)); | |
207 | if(pcm_written_frames < 0) { | |
208 | switch(pcm_written_frames) { | |
209 | case -EPIPE: /* underrun */ | |
210 | error(0, "snd_pcm_writei reports underrun"); | |
211 | if((err = snd_pcm_prepare(pcm)) < 0) | |
212 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
213 | return 0; | |
214 | case -EAGAIN: | |
215 | return 0; | |
216 | default: | |
217 | fatal(0, "error calling snd_pcm_writei: %d", | |
218 | (int)pcm_written_frames); | |
219 | } | |
220 | } else | |
221 | return pcm_written_frames; | |
222 | } | |
223 | ||
224 | static int alsa_slots, alsa_nslots = -1; | |
225 | ||
226 | /** @brief Fill in poll fd array for ALSA */ | |
e84fb5f0 | 227 | static void alsa_beforepoll(int attribute((unused)) *timeoutp) { |
1c3f1e73 | 228 | /* We send sample data to ALSA as fast as it can accept it, relying on |
229 | * the fact that it has a relatively small buffer to minimize pause | |
230 | * latency. */ | |
231 | int retry = 3, err; | |
232 | ||
233 | alsa_slots = fdno; | |
234 | do { | |
235 | retry = 0; | |
236 | alsa_nslots = snd_pcm_poll_descriptors(pcm, &fds[fdno], NFDS - fdno); | |
237 | if((alsa_nslots <= 0 | |
238 | || !(fds[alsa_slots].events & POLLOUT)) | |
239 | && snd_pcm_state(pcm) == SND_PCM_STATE_XRUN) { | |
240 | error(0, "underrun detected after call to snd_pcm_poll_descriptors()"); | |
241 | if((err = snd_pcm_prepare(pcm))) | |
242 | fatal(0, "error calling snd_pcm_prepare: %d", err); | |
243 | } else | |
244 | break; | |
245 | } while(retry-- > 0); | |
246 | if(alsa_nslots >= 0) | |
247 | fdno += alsa_nslots; | |
248 | } | |
249 | ||
250 | /** @brief Process poll() results for ALSA */ | |
251 | static int alsa_ready(void) { | |
252 | int err; | |
253 | ||
254 | unsigned short alsa_revents; | |
255 | ||
256 | if((err = snd_pcm_poll_descriptors_revents(pcm, | |
257 | &fds[alsa_slots], | |
258 | alsa_nslots, | |
259 | &alsa_revents)) < 0) | |
260 | fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err); | |
261 | if(alsa_revents & (POLLOUT | POLLERR)) | |
262 | return 1; | |
263 | else | |
264 | return 0; | |
265 | } | |
266 | ||
267 | const struct speaker_backend alsa_backend = { | |
268 | BACKEND_ALSA, | |
269 | 0, | |
270 | alsa_init, | |
271 | alsa_activate, | |
272 | alsa_play, | |
273 | alsa_deactivate, | |
274 | alsa_beforepoll, | |
275 | alsa_ready | |
276 | }; | |
277 | ||
278 | #endif | |
279 | ||
280 | /* | |
281 | Local Variables: | |
282 | c-basic-offset:2 | |
283 | comment-column:40 | |
284 | fill-column:79 | |
285 | indent-tabs-mode:nil | |
286 | End: | |
287 | */ |