Convert writers to lopsub.
[paraslash.git] / alsa_write.c
1 /*
2 * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file alsa_write.c paraslash's alsa output plugin */
8
9 /*
10 * Based in parts on aplay.c from the alsa-utils-1.0.8 package,
11 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>, which is
12 * based on the vplay program by Michael Beck.
13 */
14
15 #include <regex.h>
16 #include <sys/types.h>
17 #include <alsa/asoundlib.h>
18 #include <lopsub.h>
19
20 #include "write_cmd.lsg.h"
21 #include "para.h"
22 #include "fd.h"
23 #include "string.h"
24 #include "list.h"
25 #include "sched.h"
26 #include "buffer_tree.h"
27 #include "write.h"
28 #include "error.h"
29
30 /** Data specific to the alsa writer. */
31 struct private_alsa_write_data {
32 /** The alsa handle */
33 snd_pcm_t *handle;
34 /** Determined and set by alsa_init(). */
35 int bytes_per_frame;
36 /*
37 * If the sample rate is not given at the command line and no wav
38 * header was detected, the btr exec mechanism is employed to query the
39 * ancestor buffer tree nodes for this information. In a typical setup
40 * the decoder passes the sample rate back to the alsa writer.
41 *
42 * \sa \ref btr_exec_up().
43 */
44 unsigned sample_rate;
45 /*
46 * The sample format (8/16 bit, signed/unsigned, little/big endian) is
47 * determined in the same way as the \a sample_rate.
48 */
49 snd_pcm_format_t sample_format;
50 /* The number of channels, again determined like \a sample_rate. */
51 unsigned channels;
52 /* time until buffer underrun occurs, in milliseconds */
53 unsigned buffer_time;
54 struct timeval drain_barrier;
55 /* File descriptor for select(). */
56 int poll_fd;
57 };
58
59 static snd_pcm_format_t get_alsa_pcm_format(enum sample_format sf)
60 {
61 switch (sf) {
62 case SF_S8: return SND_PCM_FORMAT_S8;
63 case SF_U8: return SND_PCM_FORMAT_U8;
64 case SF_S16_LE: return SND_PCM_FORMAT_S16_LE;
65 case SF_S16_BE: return SND_PCM_FORMAT_S16_BE;
66 case SF_U16_LE: return SND_PCM_FORMAT_U16_LE;
67 case SF_U16_BE: return SND_PCM_FORMAT_U16_BE;
68 default: return SND_PCM_FORMAT_S16_LE;
69 }
70 }
71
72 /* Install PCM software and hardware configuration. */
73 static int alsa_init(struct writer_node *wn)
74 {
75 struct private_alsa_write_data *pad = wn->private_data;
76 snd_pcm_hw_params_t *hwparams = NULL;
77 snd_pcm_sw_params_t *swparams = NULL;
78 snd_pcm_uframes_t start_threshold, stop_threshold;
79 snd_pcm_uframes_t buffer_size, period_size;
80 snd_output_t *output_log;
81 int ret;
82 const char *msg, *dev = WRITE_CMD_OPT_STRING_VAL(ALSA, DEVICE, wn->lpr);
83 unsigned period_time;
84
85 PARA_INFO_LOG("opening %s\n", dev);
86 msg = "unable to open pcm";
87 ret = snd_pcm_open(&pad->handle, dev, SND_PCM_STREAM_PLAYBACK,
88 SND_PCM_NONBLOCK);
89 if (ret < 0)
90 goto fail;
91 ret = snd_pcm_hw_params_malloc(&hwparams);
92 assert(ret >= 0);
93 msg = "Broken alsa configuration";
94 ret = snd_pcm_hw_params_any(pad->handle, hwparams);
95 if (ret < 0)
96 goto fail;
97 msg = "access type not available";
98 ret = snd_pcm_hw_params_set_access(pad->handle, hwparams,
99 SND_PCM_ACCESS_RW_INTERLEAVED);
100 if (ret < 0)
101 goto fail;
102 msg = "sample format not available";
103 ret = snd_pcm_hw_params_set_format(pad->handle, hwparams,
104 pad->sample_format);
105 if (ret < 0)
106 goto fail;
107 msg = "channels count not available";
108 ret = snd_pcm_hw_params_set_channels(pad->handle, hwparams,
109 pad->channels);
110 if (ret < 0)
111 goto fail;
112 msg = "could not set sample rate";
113 ret = snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
114 &pad->sample_rate, NULL);
115 if (ret < 0)
116 goto fail;
117 /* alsa wants microseconds */
118 pad->buffer_time = 1000U * WRITE_CMD_OPT_UINT32_VAL(ALSA, BUFFER_TIME,
119 wn->lpr);
120 msg = "could not set buffer time";
121 ret = snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
122 &pad->buffer_time, NULL);
123 if (ret < 0)
124 goto fail;
125 pad->buffer_time /= 1000; /* we prefer milliseconds */
126 period_time = pad->buffer_time * 250; /* buffer time / 4 */
127 msg = "could not set period time";
128 ret = snd_pcm_hw_params_set_period_time_near(pad->handle, hwparams,
129 &period_time, NULL);
130 if (ret < 0)
131 goto fail;
132
133 msg = "unable to install hw params";
134 ret = snd_pcm_hw_params(pad->handle, hwparams);
135 if (ret < 0)
136 goto fail;
137 snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
138 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
139 msg = "period size equals buffer size";
140 if (period_size == buffer_size)
141 goto fail;
142
143 /* software parameter setup */
144 ret = snd_pcm_sw_params_malloc(&swparams);
145 assert(ret >= 0);
146 snd_pcm_sw_params_current(pad->handle, swparams);
147 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
148 if (buffer_size < 1)
149 start_threshold = 1;
150 else
151 start_threshold = PARA_MIN(buffer_size,
152 (snd_pcm_uframes_t)pad->sample_rate);
153 msg = "could not set start threshold";
154 ret = snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
155 start_threshold);
156 if (ret < 0)
157 goto fail;
158 stop_threshold = buffer_size;
159 msg = "could not set stop threshold";
160 ret = snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
161 stop_threshold);
162 if (ret < 0)
163 goto fail;
164 msg = "unable to install sw params";
165 ret = snd_pcm_sw_params(pad->handle, swparams);
166 if (ret < 0)
167 goto fail;
168 msg = "unable to determine bytes per frame";
169 ret = snd_pcm_format_physical_width(pad->sample_format);
170 if (ret <= 0)
171 goto fail;
172 pad->bytes_per_frame = ret * pad->channels / 8;
173 msg = "failed to set alsa handle to nonblock mode";
174 ret = snd_pcm_nonblock(pad->handle, 1);
175 if (ret < 0)
176 goto fail;
177 ret = snd_output_buffer_open(&output_log);
178 if (ret == 0) {
179 char *buf, *p;
180 size_t sz;
181 PARA_DEBUG_LOG("dumping alsa configuration\n");
182 snd_pcm_dump(pad->handle, output_log);
183 snd_pcm_hw_params_dump(hwparams, output_log);
184 sz = snd_output_buffer_string(output_log, &buf);
185 for (p = buf; p < buf + sz;) {
186 char *q = memchr(p, '\n', buf + sz - p);
187 if (!q)
188 break;
189 *q = '\0';
190 PARA_DEBUG_LOG("%s\n", p);
191 p = q + 1;
192 }
193 snd_output_close(output_log);
194 }
195 ret = 1;
196 goto out;
197 fail:
198 if (ret < 0)
199 PARA_ERROR_LOG("%s: %s\n", msg, snd_strerror(-ret));
200 else
201 PARA_ERROR_LOG("%s\n", msg);
202 ret = -E_ALSA;
203 out:
204 snd_pcm_hw_params_free(hwparams);
205 snd_pcm_sw_params_free(swparams);
206 return ret;
207 }
208
209 static void alsa_write_pre_select(struct sched *s, void *context)
210 {
211 struct pollfd pfd;
212 struct writer_node *wn = context;
213 struct private_alsa_write_data *pad = wn->private_data;
214 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
215
216 if (pad)
217 pad->poll_fd = -1;
218 if (ret == 0)
219 return;
220 if (!pad) {
221 sched_min_delay(s);
222 return;
223 }
224 if (ret < 0) {
225 sched_request_barrier_or_min_delay(&pad->drain_barrier, s);
226 return;
227 }
228 /* wait at most 50% of the buffer time */
229 sched_request_timeout_ms(pad->buffer_time / 2, s);
230 ret = snd_pcm_poll_descriptors(pad->handle, &pfd, 1);
231 if (ret < 0) {
232 PARA_ERROR_LOG("could not get alsa poll fd: %s\n",
233 snd_strerror(-ret));
234 return;
235 }
236 pad->poll_fd = pfd.fd;
237 para_fd_set(pfd.fd, &s->rfds, &s->max_fileno);
238 }
239
240 static void alsa_close(struct writer_node *wn)
241 {
242 struct private_alsa_write_data *pad = wn->private_data;
243 PARA_INFO_LOG("closing writer node %p\n", wn);
244
245 if (!pad)
246 return;
247 /*
248 * It's OK to have a blocking operation here because we already made
249 * sure that the PCM output buffer is (nearly) empty.
250 */
251 snd_pcm_nonblock(pad->handle, 0);
252 snd_pcm_drain(pad->handle);
253 snd_pcm_close(pad->handle);
254 snd_config_update_free_global();
255 free(pad);
256 }
257
258 static int alsa_write_post_select(__a_unused struct sched *s, void *context)
259 {
260 struct writer_node *wn = context;
261 struct private_alsa_write_data *pad = wn->private_data;
262 struct btr_node *btrn = wn->btrn;
263 char *data;
264 size_t bytes;
265 snd_pcm_sframes_t frames;
266 int ret;
267
268 ret = task_get_notification(wn->task);
269 if (ret < 0)
270 goto err;
271 again:
272 ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
273 if (ret == 0)
274 return 0;
275 btr_merge(btrn, wn->min_iqs);
276 bytes = btr_next_buffer(btrn, &data);
277 if (ret < 0 || bytes < wn->min_iqs) { /* eof */
278 assert(btr_no_parent(btrn));
279 ret = -E_WRITE_COMMON_EOF;
280 if (!pad)
281 goto err;
282 /* wait until pending frames are played */
283 if (pad->drain_barrier.tv_sec == 0) {
284 PARA_DEBUG_LOG("waiting for device to drain\n");
285 tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000),
286 &pad->drain_barrier);
287 return 0;
288 }
289 if (tv_diff(now, &pad->drain_barrier, NULL) > 0)
290 goto err;
291 return 0;
292 }
293 if (!pad) {
294 int32_t val;
295
296 if (bytes == 0) /* no data available */
297 return 0;
298 pad = wn->private_data = para_calloc(sizeof(*pad));
299 get_btr_sample_rate(btrn, &val);
300 pad->sample_rate = val;
301 get_btr_channels(btrn, &val);
302 pad->channels = val;
303 get_btr_sample_format(btrn, &val);
304 pad->sample_format = get_alsa_pcm_format(val);
305
306 PARA_INFO_LOG("%u channel(s), %uHz\n", pad->channels,
307 pad->sample_rate);
308 ret = alsa_init(wn);
309 if (ret < 0) {
310 free(wn->private_data);
311 wn->private_data = NULL;
312 goto err;
313 }
314 wn->min_iqs = pad->bytes_per_frame;
315 goto again;
316 }
317 frames = bytes / pad->bytes_per_frame;
318 frames = snd_pcm_writei(pad->handle, data, frames);
319 if (frames == 0 || frames == -EAGAIN) {
320 char buf[100];
321 if (pad->poll_fd >= 0 && FD_ISSET(pad->poll_fd, &s->rfds))
322 if (read(pad->poll_fd, buf, 100))
323 do_nothing;
324 return 0;
325 }
326 if (frames > 0) {
327 btr_consume(btrn, frames * pad->bytes_per_frame);
328 goto again;
329 }
330 if (frames == -EPIPE) {
331 PARA_WARNING_LOG("underrun (tried to write %zu bytes)\n", bytes);
332 snd_pcm_prepare(pad->handle);
333 return 0;
334 }
335 PARA_ERROR_LOG("alsa write error: %s\n", snd_strerror(-frames));
336 ret = -E_ALSA;
337 err:
338 assert(ret < 0);
339 btr_remove_node(&wn->btrn);
340 return ret;
341 }
342
343 struct writer lsg_write_cmd_com_alsa_user_data = {
344
345 .pre_select = alsa_write_pre_select,
346 .post_select = alsa_write_post_select,
347 .close = alsa_close,
348 };