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init script always address local instance of daemon
[disorder] / clients / playrtp-alsa.c
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c593cf7c 1/*
2 * This file is part of DisOrder.
3 * Copyright (C) 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 clients/playrtp-alsa.c
21 * @brief RTP player - ALSA support
22 */
23
24#include <config.h>
25
146e86fb 26#if HAVE_ALSA_ASOUNDLIB_H
c593cf7c 27#include "types.h"
28
29#include <poll.h>
30#include <alsa/asoundlib.h>
31#include <assert.h>
32#include <pthread.h>
33
34#include "mem.h"
35#include "log.h"
36#include "vector.h"
37#include "heap.h"
38#include "playrtp.h"
39
40/** @brief PCM handle */
41static snd_pcm_t *pcm;
42
43/** @brief True when @ref pcm is up and running */
44static int playrtp_alsa_prepared = 1;
45
46static void playrtp_alsa_init(void) {
47 snd_pcm_hw_params_t *hwparams;
48 snd_pcm_sw_params_t *swparams;
49 /* Only support one format for now */
50 const int sample_format = SND_PCM_FORMAT_S16_BE;
51 unsigned rate = 44100;
52 const int channels = 2;
53 const int samplesize = channels * sizeof(uint16_t);
54 snd_pcm_uframes_t pcm_bufsize = MAXSAMPLES * samplesize * 3;
55 /* If we can write more than this many samples we'll get a wakeup */
56 const int avail_min = 256;
57 int err;
58
59 /* Open ALSA */
60 if((err = snd_pcm_open(&pcm,
61 device ? device : "default",
62 SND_PCM_STREAM_PLAYBACK,
63 SND_PCM_NONBLOCK)))
64 fatal(0, "error from snd_pcm_open: %d", err);
65 /* Set up 'hardware' parameters */
66 snd_pcm_hw_params_alloca(&hwparams);
67 if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0)
68 fatal(0, "error from snd_pcm_hw_params_any: %d", err);
69 if((err = snd_pcm_hw_params_set_access(pcm, hwparams,
70 SND_PCM_ACCESS_RW_INTERLEAVED)) < 0)
71 fatal(0, "error from snd_pcm_hw_params_set_access: %d", err);
72 if((err = snd_pcm_hw_params_set_format(pcm, hwparams,
73 sample_format)) < 0)
74
75 fatal(0, "error from snd_pcm_hw_params_set_format (%d): %d",
76 sample_format, err);
77 if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0)
78 fatal(0, "error from snd_pcm_hw_params_set_rate (%d): %d",
79 rate, err);
80 if((err = snd_pcm_hw_params_set_channels(pcm, hwparams,
81 channels)) < 0)
82 fatal(0, "error from snd_pcm_hw_params_set_channels (%d): %d",
83 channels, err);
84 if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams,
85 &pcm_bufsize)) < 0)
86 fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d",
87 MAXSAMPLES * samplesize * 3, err);
88 if((err = snd_pcm_hw_params(pcm, hwparams)) < 0)
89 fatal(0, "error calling snd_pcm_hw_params: %d", err);
90 /* Set up 'software' parameters */
91 snd_pcm_sw_params_alloca(&swparams);
92 if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0)
93 fatal(0, "error calling snd_pcm_sw_params_current: %d", err);
94 if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, avail_min)) < 0)
95 fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d",
96 avail_min, err);
97 if((err = snd_pcm_sw_params(pcm, swparams)) < 0)
98 fatal(0, "error calling snd_pcm_sw_params: %d", err);
99}
100
101/** @brief Wait until ALSA wants some audio */
102static void wait_alsa(void) {
103 struct pollfd fds[64];
104 int nfds, err;
105 unsigned short events;
106
107 for(;;) {
108 do {
109 if((nfds = snd_pcm_poll_descriptors(pcm,
110 fds, sizeof fds / sizeof *fds)) < 0)
111 fatal(0, "error calling snd_pcm_poll_descriptors: %d", nfds);
112 } while(poll(fds, nfds, -1) < 0 && errno == EINTR);
113 if((err = snd_pcm_poll_descriptors_revents(pcm, fds, nfds, &events)))
114 fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err);
115 if(events & POLLOUT)
116 return;
117 }
118}
119
120/** @brief Play some sound via ALSA
121 * @param s Pointer to sample data
122 * @param n Number of samples
123 * @return 0 on success, -1 on non-fatal error
124 */
125static int playrtp_alsa_writei(const void *s, size_t n) {
126 /* Do the write */
127 const snd_pcm_sframes_t frames_written = snd_pcm_writei(pcm, s, n / 2);
128 if(frames_written < 0) {
129 /* Something went wrong */
130 switch(frames_written) {
131 case -EAGAIN:
132 return 0;
133 case -EPIPE:
134 error(0, "error calling snd_pcm_writei: %ld",
135 (long)frames_written);
136 return -1;
137 default:
138 fatal(0, "error calling snd_pcm_writei: %ld",
139 (long)frames_written);
140 }
141 } else {
142 /* Success */
143 next_timestamp += frames_written * 2;
144 return 0;
145 }
146}
147
148/** @brief Play the relevant part of a packet
149 * @param p Packet to play
150 * @return 0 on success, -1 on non-fatal error
151 */
152static int playrtp_alsa_play(const struct packet *p) {
153 return playrtp_alsa_writei(p->samples_raw + next_timestamp - p->timestamp,
154 (p->timestamp + p->nsamples) - next_timestamp);
155}
156
157/** @brief Play some silence
158 * @param p Next packet or NULL
159 * @return 0 on success, -1 on non-fatal error
160 */
161static int playrtp_alsa_infill(const struct packet *p) {
162 static const uint16_t zeros[INFILL_SAMPLES];
163 size_t samples_available = INFILL_SAMPLES;
164
165 if(p && samples_available > p->timestamp - next_timestamp)
166 samples_available = p->timestamp - next_timestamp;
167 return playrtp_alsa_writei(zeros, samples_available);
168}
169
170static void playrtp_alsa_enable(void){
171 int err;
172
173 if(!playrtp_alsa_prepared) {
174 if((err = snd_pcm_prepare(pcm)))
175 fatal(0, "error calling snd_pcm_prepare: %d", err);
176 playrtp_alsa_prepared = 1;
177 }
178}
179
180/** @brief Reset ALSA state after we lost synchronization */
181static void playrtp_alsa_disable(int hard_reset) {
182 int err;
183
184 if((err = snd_pcm_nonblock(pcm, 0)))
185 fatal(0, "error calling snd_pcm_nonblock: %d", err);
186 if(hard_reset) {
187 if((err = snd_pcm_drop(pcm)))
188 fatal(0, "error calling snd_pcm_drop: %d", err);
189 } else
190 if((err = snd_pcm_drain(pcm)))
191 fatal(0, "error calling snd_pcm_drain: %d", err);
192 if((err = snd_pcm_nonblock(pcm, 1)))
193 fatal(0, "error calling snd_pcm_nonblock: %d", err);
194 playrtp_alsa_prepared = 0;
195}
196
197void playrtp_alsa(void) {
198 int escape;
199 const struct packet *p;
200
201 playrtp_alsa_init();
202 pthread_mutex_lock(&lock);
203 for(;;) {
204 /* Wait for the buffer to fill up a bit */
205 playrtp_fill_buffer();
206 playrtp_alsa_enable();
207 escape = 0;
208 info("Playing...");
209 /* Keep playing until the buffer empties out, or ALSA tells us to get
210 * lost */
211 while((nsamples >= minbuffer
212 || (nsamples > 0
213 && contains(pheap_first(&packets), next_timestamp)))
214 && !escape) {
215 /* Wait for ALSA to ask us for more data */
216 pthread_mutex_unlock(&lock);
217 wait_alsa();
218 pthread_mutex_lock(&lock);
219 /* ALSA is ready for more data, find something to play */
220 p = playrtp_next_packet();
221 /* Play it or play some silence */
222 if(contains(p, next_timestamp))
223 escape = playrtp_alsa_play(p);
224 else
225 escape = playrtp_alsa_infill(p);
226 }
227 active = 0;
228 /* We stop playing for a bit until the buffer re-fills */
229 pthread_mutex_unlock(&lock);
230 playrtp_alsa_disable(escape);
231 pthread_mutex_lock(&lock);
232 }
233}
234
235#endif
236
237/*
238Local Variables:
239c-basic-offset:2
240comment-column:40
241fill-column:79
242indent-tabs-mode:nil
243End:
244*/