alsa: Ignore errors from the btr query.
[paraslash.git] / alsa_write.c
1 /*
2 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
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 <dirent.h>
18 #include <alsa/asoundlib.h>
19 #include <sys/time.h>
20 #include <stdbool.h>
21
22 #include "para.h"
23 #include "fd.h"
24 #include "string.h"
25 #include "list.h"
26 #include "sched.h"
27 #include "ggo.h"
28 #include "buffer_tree.h"
29 #include "write.h"
30 #include "write_common.h"
31 #include "alsa_write.cmdline.h"
32 #include "error.h"
33
34 /** always use 16 bit little endian */
35 #define FORMAT SND_PCM_FORMAT_S16_LE
36
37 /** Data specific to the alsa writer. */
38 struct private_alsa_write_data {
39 /** The alsa handle */
40 snd_pcm_t *handle;
41 /** Determined and set by alsa_open(). */
42 int bytes_per_frame; /* TODO: Kill this after btr switch */
43 /** The approximate maximum buffer duration in us. */
44 unsigned buffer_time;
45 /* Number of frames that fit into the buffer. */
46 snd_pcm_uframes_t buffer_frames;
47 /**
48 * The samplerate given by command line option or the decoder
49 * of the writer node group.
50 */
51 unsigned samplerate;
52 /**
53 * The number of channels, given by command line option or the
54 * decoder of the writer node group.
55 */
56 unsigned channels;
57 };
58
59 /* Install PCM software and hardware configuration. */
60 static int alsa_init(struct private_alsa_write_data *pad,
61 struct alsa_write_args_info *conf)
62 {
63 snd_pcm_hw_params_t *hwparams;
64 snd_pcm_sw_params_t *swparams;
65 snd_pcm_uframes_t start_threshold, stop_threshold;
66 snd_pcm_uframes_t period_size;
67 int err;
68
69 PARA_INFO_LOG("opening %s\n", conf->device_arg);
70 err = snd_pcm_open(&pad->handle, conf->device_arg,
71 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
72 if (err < 0)
73 return -E_PCM_OPEN;
74
75 snd_pcm_hw_params_alloca(&hwparams);
76 snd_pcm_sw_params_alloca(&swparams);
77 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
78 return -E_BROKEN_CONF;
79 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
80 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
81 return -E_ACCESS_TYPE;
82 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
83 return -E_SAMPLE_FORMAT;
84 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
85 pad->channels) < 0)
86 return -E_CHANNEL_COUNT;
87 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
88 &pad->samplerate, NULL) < 0)
89 return -E_SET_RATE;
90 err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
91 &pad->buffer_time, NULL);
92 if (err < 0 || !pad->buffer_time)
93 return -E_GET_BUFFER_TIME;
94 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
95 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
96 &pad->buffer_time, NULL) < 0)
97 return -E_SET_BUFFER_TIME;
98 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
99 return -E_HW_PARAMS;
100 snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
101 snd_pcm_hw_params_get_buffer_size(hwparams, &pad->buffer_frames);
102 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", pad->buffer_frames,
103 period_size);
104 if (period_size == pad->buffer_frames)
105 return -E_BAD_PERIOD;
106 snd_pcm_sw_params_current(pad->handle, swparams);
107 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
108 if (pad->buffer_frames < 1)
109 start_threshold = 1;
110 else
111 start_threshold = PARA_MIN(pad->buffer_frames,
112 (snd_pcm_uframes_t)pad->samplerate);
113 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
114 start_threshold) < 0)
115 return -E_START_THRESHOLD;
116 stop_threshold = pad->buffer_frames;
117 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
118 stop_threshold) < 0)
119 return -E_STOP_THRESHOLD;
120 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
121 PARA_WARNING_LOG("unable to install sw params\n");
122 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
123 * pad->channels / 8;
124 if (pad->bytes_per_frame <= 0)
125 return -E_PHYSICAL_WIDTH;
126 PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
127 if (snd_pcm_nonblock(pad->handle, 1))
128 PARA_ERROR_LOG("failed to set nonblock mode\n");
129 return 1;
130 }
131
132 /* Open an instance of the alsa writer. */
133 static int alsa_open_nobtr(struct writer_node *wn)
134 {
135 struct alsa_write_args_info *conf = wn->conf;
136 struct writer_node_group *wng = wn->wng;
137 struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
138
139 wn->private_data = pad;
140 if (!conf->samplerate_given && wng->samplerate)
141 pad->samplerate = *wng->samplerate;
142 else
143 pad->samplerate = conf->samplerate_arg;
144 if (!conf->channels_given && wng->channels)
145 pad->channels = *wng->channels;
146 else
147 pad->channels = conf->channels_arg;
148 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
149 return 1;
150 }
151
152 static int alsa_open_btr(struct writer_node *wn)
153 {
154 struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
155
156 wn->private_data = pad;
157 return 1;
158 }
159 static int alsa_open(struct writer_node *wn)
160 {
161 if (wn->btrn)
162 return alsa_open_btr(wn);
163 return alsa_open_nobtr(wn);
164 }
165
166 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
167 {
168 struct private_alsa_write_data *pad = wn->private_data;
169 struct writer_node_group *wng = wn->wng;
170 struct timeval tv;
171 snd_pcm_sframes_t avail, underrun;
172
173 if (!pad->handle)
174 return 1;
175 if (wn->btrn) {
176 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
177 if (ret == 0)
178 return 1;
179 if (ret < 0) {
180 sched_request_timeout_ms(20, s);
181 return 42;
182 }
183 } else {
184 if (*wng->loaded - wn->written < pad->bytes_per_frame)
185 return 1;
186 }
187 /*
188 * Data is available to be written to the alsa handle. Compute number
189 * of milliseconds until next buffer underrun would occur.
190 *
191 * snd_pcm_avail_update() updates the current available count of
192 * samples for writing. It is a light method to obtain current stream
193 * position, because it does not require the user <-> kernel context
194 * switch, but the value is less accurate, because ring buffer pointers
195 * are updated in kernel drivers only when an interrupt occurs.
196 */
197 avail = snd_pcm_avail_update(pad->handle);
198 if (avail < 0)
199 avail = 0;
200 underrun = (pad->buffer_frames - avail) * pad->buffer_time
201 / pad->buffer_frames / 1000;
202 if (underrun < 50)
203 underrun = 50;
204 underrun -= 50;
205 ms2tv(underrun, &tv);
206 if (tv_diff(&s->timeout, &tv, NULL) > 0)
207 s->timeout = tv;
208 //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
209 return 1;
210 }
211
212 static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
213 {
214 struct writer_node *wn = container_of(t, struct writer_node, task);
215 alsa_write_pre_select(s, wn);
216 }
217
218 static void xrun(snd_pcm_t *handle)
219 {
220 snd_pcm_status_t *status;
221 int ret;
222 struct timeval tv, diff;
223
224 snd_pcm_status_alloca(&status);
225 ret = snd_pcm_status(handle, status);
226 if (ret < 0)
227 return;
228 if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
229 return;
230 snd_pcm_status_get_trigger_tstamp(status, &tv);
231 tv_diff(now, &tv, &diff);
232 PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
233 }
234
235 static int alsa_write_post_select(__a_unused struct sched *s,
236 struct writer_node *wn)
237 {
238 struct private_alsa_write_data *pad = wn->private_data;
239 struct writer_node_group *wng = wn->wng;
240 size_t bytes = *wng->loaded - wn->written;
241 unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
242 snd_pcm_sframes_t ret, frames, avail;
243
244 if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
245 wn->written = *wng->loaded;
246 return *wng->input_error;
247 }
248 if (!bytes) /* no data available */
249 return 0;
250 if (!pad->handle) {
251 int err = alsa_init(pad, wn->conf);
252 if (err < 0)
253 return err;
254 }
255 frames = bytes / pad->bytes_per_frame;
256 if (!frames) /* less than a single frame available */
257 return 0;
258 avail = snd_pcm_avail_update(pad->handle);
259 if (avail <= 0)
260 return 0;
261 frames = PARA_MIN(frames, avail);
262 ret = snd_pcm_writei(pad->handle, data, frames);
263 if (ret >= 0) {
264 wn->written += ret * pad->bytes_per_frame;
265 return 1;
266 }
267 if (ret == -EPIPE) {
268 xrun(pad->handle);
269 snd_pcm_prepare(pad->handle);
270 return 0;
271 }
272 PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
273 if (ret == -EAGAIN)
274 return 0;
275 return -E_ALSA_WRITE;
276 }
277
278 static void alsa_close(struct writer_node *wn)
279 {
280 struct private_alsa_write_data *pad = wn->private_data;
281 PARA_INFO_LOG("closing writer node %p\n", wn);
282
283 if (pad->handle) {
284 /*
285 * It's OK to have a blocking operation here because we already
286 * made sure that the PCM output buffer is (nearly) empty.
287 */
288 snd_pcm_nonblock(pad->handle, 0);
289 snd_pcm_drain(pad->handle);
290 snd_pcm_close(pad->handle);
291 snd_config_update_free_global();
292 }
293 free(pad);
294 }
295
296 static void alsa_write_post_select_btr(__a_unused struct sched *s,
297 struct task *t)
298 {
299 struct writer_node *wn = container_of(t, struct writer_node, task);
300 struct private_alsa_write_data *pad = wn->private_data;
301 struct btr_node *btrn = wn->btrn;
302 char *data;
303 size_t bytes;
304 snd_pcm_sframes_t frames, avail;
305 int ret;
306
307 again:
308 t->error = 0;
309 ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
310 if (ret == 0)
311 return;
312 btr_merge(btrn, wn->min_iqs);
313 bytes = btr_next_buffer(btrn, &data);
314 if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
315 assert(btr_no_parent(btrn));
316 ret = -E_ALSA_EOF;
317 if (!pad->handle)
318 goto err;
319 /* wait until pending frames are played */
320 avail = snd_pcm_avail_update(pad->handle);
321 if (avail + 1000 > pad->buffer_frames)
322 goto err;
323 PARA_DEBUG_LOG("waiting for device to drain\n");
324 return;
325 }
326 if (!pad->handle) {
327 struct alsa_write_args_info *conf = wn->conf;
328 if (bytes == 0) /* no data available */
329 return;
330 /* defaults */
331 pad->samplerate = conf->samplerate_arg;
332 pad->channels = conf->channels_arg;
333 if (!conf->samplerate_given) { /* config option trumps btr_exec */
334 int32_t rate;
335 if (get_btr_samplerate(btrn, &rate) >= 0)
336 pad->samplerate = rate;
337 }
338 if (!conf->channels_given) {
339 int32_t ch;
340 if (get_btr_channels(btrn, &ch) >= 0)
341 pad->channels = ch;
342 }
343 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
344 ret = 1;
345 ret = alsa_init(pad, wn->conf);
346 if (ret < 0)
347 goto err;
348 wn->min_iqs = pad->bytes_per_frame;
349 }
350 frames = bytes / pad->bytes_per_frame;
351 frames = snd_pcm_writei(pad->handle, data, frames);
352 if (frames >= 0) {
353 btr_consume(btrn, frames * pad->bytes_per_frame);
354 goto again;
355 }
356 if (frames == -EPIPE) {
357 xrun(pad->handle);
358 snd_pcm_prepare(pad->handle);
359 return;
360 }
361 if (frames == -EAGAIN)
362 return;
363 PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
364 ret = -E_ALSA_WRITE;
365 err:
366 assert(ret < 0);
367 t->error = ret;
368 }
369
370 __malloc static void *alsa_parse_config(const char *options)
371 {
372 int ret;
373 struct alsa_write_args_info *conf
374 = para_calloc(sizeof(struct alsa_write_args_info));
375
376 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
377 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
378 if (ret)
379 goto err_out;
380 PARA_INFO_LOG("help given: %d\n", conf->help_given);
381 return conf;
382 err_out:
383 free(conf);
384 return NULL;
385 }
386
387 static void alsa_free_config(void *conf)
388 {
389 alsa_cmdline_parser_free(conf);
390 }
391
392 /**
393 * The init function of the alsa writer.
394 *
395 * \param w Pointer to the writer to initialize.
396 *
397 * \sa \ref struct writer.
398 */
399 void alsa_write_init(struct writer *w)
400 {
401 struct alsa_write_args_info dummy;
402
403 alsa_cmdline_parser_init(&dummy);
404 w->open = alsa_open;
405 w->close = alsa_close;
406 w->pre_select = alsa_write_pre_select;
407 w->pre_select_btr = alsa_write_pre_select_btr;
408 w->post_select = alsa_write_post_select;
409 w->post_select_btr = alsa_write_post_select_btr;
410 w->parse_config = alsa_parse_config;
411 w->shutdown = NULL; /* nothing to do */
412 w->free_config = alsa_free_config;
413 w->help = (struct ggo_help) {
414 .short_help = alsa_write_args_info_help,
415 .detailed_help = alsa_write_args_info_detailed_help
416 };
417 alsa_cmdline_parser_free(&dummy);
418 }