chiark / gitweb /
Remove some obsolete code
[disorder] / server / speaker-alsa.c
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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 */
40static snd_pcm_t *pcm;
41
42/** @brief Last seen buffer size */
43static snd_pcm_uframes_t last_pcm_bufsize;
44
45/** @brief ALSA backend initialization */
46static void alsa_init(void) {
47 info("selected ALSA backend");
48}
49
50/** @brief Log ALSA parameters */
51static 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 */
77static 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 */
94static 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;
180fatal:
181 abandon();
182error:
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 */
193static 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
219static int alsa_slots, alsa_nslots = -1;
220
221/** @brief Fill in poll fd array for ALSA */
e84fb5f0 222static 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 */
246static 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
262const 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/*
276Local Variables:
277c-basic-offset:2
278comment-column:40
279fill-column:79
280indent-tabs-mode:nil
281End:
282*/