Switch audiod over to the buffer tree API.
[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 underrun = 10;
181 goto timeout;
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 timeout:
206 ms2tv(underrun, &tv);
207 if (tv_diff(&s->timeout, &tv, NULL) > 0)
208 s->timeout = tv;
209 //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
210 return 1;
211 }
212
213 static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
214 {
215 struct writer_node *wn = container_of(t, struct writer_node, task);
216 alsa_write_pre_select(s, wn);
217 }
218
219 static void xrun(snd_pcm_t *handle)
220 {
221 snd_pcm_status_t *status;
222 int ret;
223 struct timeval tv, diff;
224
225 snd_pcm_status_alloca(&status);
226 ret = snd_pcm_status(handle, status);
227 if (ret < 0)
228 return;
229 if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
230 return;
231 snd_pcm_status_get_trigger_tstamp(status, &tv);
232 tv_diff(now, &tv, &diff);
233 PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
234 }
235
236 static int alsa_write_post_select(__a_unused struct sched *s,
237 struct writer_node *wn)
238 {
239 struct private_alsa_write_data *pad = wn->private_data;
240 struct writer_node_group *wng = wn->wng;
241 size_t bytes = *wng->loaded - wn->written;
242 unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
243 snd_pcm_sframes_t ret, frames, avail;
244
245 if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
246 wn->written = *wng->loaded;
247 return *wng->input_error;
248 }
249 if (!bytes) /* no data available */
250 return 0;
251 if (!pad->handle) {
252 int err = alsa_init(pad, wn->conf);
253 if (err < 0)
254 return err;
255 }
256 frames = bytes / pad->bytes_per_frame;
257 if (!frames) /* less than a single frame available */
258 return 0;
259 avail = snd_pcm_avail_update(pad->handle);
260 if (avail <= 0)
261 return 0;
262 frames = PARA_MIN(frames, avail);
263 ret = snd_pcm_writei(pad->handle, data, frames);
264 if (ret >= 0) {
265 wn->written += ret * pad->bytes_per_frame;
266 return 1;
267 }
268 if (ret == -EPIPE) {
269 xrun(pad->handle);
270 snd_pcm_prepare(pad->handle);
271 return 0;
272 }
273 PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
274 if (ret == -EAGAIN)
275 return 0;
276 return -E_ALSA_WRITE;
277 }
278
279 static void alsa_close(struct writer_node *wn)
280 {
281 struct private_alsa_write_data *pad = wn->private_data;
282 PARA_INFO_LOG("closing writer node %p\n", wn);
283
284 if (pad->handle) {
285 /*
286 * It's OK to have a blocking operation here because we already
287 * made sure that the PCM output buffer is (nearly) empty.
288 */
289 snd_pcm_nonblock(pad->handle, 0);
290 snd_pcm_drain(pad->handle);
291 snd_pcm_close(pad->handle);
292 snd_config_update_free_global();
293 }
294 free(pad);
295 }
296
297 static void alsa_write_post_select_btr(__a_unused struct sched *s,
298 struct task *t)
299 {
300 struct writer_node *wn = container_of(t, struct writer_node, task);
301 struct private_alsa_write_data *pad = wn->private_data;
302 struct btr_node *btrn = wn->btrn;
303 char *data;
304 size_t bytes;
305 snd_pcm_sframes_t frames, avail;
306 int ret;
307
308 again:
309 t->error = 0;
310 ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
311 if (ret == 0)
312 return;
313 btr_merge(btrn, wn->min_iqs);
314 bytes = btr_next_buffer(btrn, &data);
315 if (ret < 0 || bytes < pad->bytes_per_frame) { /* eof */
316 assert(btr_no_parent(btrn));
317 ret = -E_ALSA_EOF;
318 if (!pad->handle)
319 goto err;
320 /* wait until pending frames are played */
321 avail = snd_pcm_avail_update(pad->handle);
322 if (avail + 1000 > pad->buffer_frames)
323 goto err;
324 PARA_DEBUG_LOG("waiting for device to drain\n");
325 return;
326 }
327 if (!pad->handle) {
328 struct alsa_write_args_info *conf = wn->conf;
329 if (bytes == 0) /* no data available */
330 return;
331 /* defaults */
332 pad->samplerate = conf->samplerate_arg;
333 pad->channels = conf->channels_arg;
334 if (!conf->samplerate_given) { /* config option trumps btr_exec */
335 int32_t rate;
336 ret = get_btr_samplerate(btrn, &rate);
337 if (ret < 0)
338 goto err;
339 pad->samplerate = rate;
340 }
341 if (!conf->channels_given) {
342 int32_t ch;
343 ret = get_btr_channels(btrn, &ch);
344 if (ret < 0)
345 goto err;
346 pad->channels = ch;
347 }
348 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
349 ret = 1;
350 ret = alsa_init(pad, wn->conf);
351 if (ret < 0)
352 goto err;
353 wn->min_iqs = pad->bytes_per_frame;
354 }
355 frames = bytes / pad->bytes_per_frame;
356 avail = snd_pcm_avail_update(pad->handle);
357 if (avail <= 0)
358 return;
359 frames = PARA_MIN(frames, avail);
360 //PARA_CRIT_LOG("writing %ld frames\n", frames);
361 frames = snd_pcm_writei(pad->handle, data, frames);
362 if (frames >= 0) {
363 btr_consume(btrn, frames * pad->bytes_per_frame);
364 goto again;
365 }
366 if (frames == -EPIPE) {
367 xrun(pad->handle);
368 snd_pcm_prepare(pad->handle);
369 return;
370 }
371 PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
372 if (frames == -EAGAIN)
373 return;
374 ret = -E_ALSA_WRITE;
375 err:
376 assert(ret < 0);
377 t->error = ret;
378 }
379
380 __malloc static void *alsa_parse_config(const char *options)
381 {
382 int ret;
383 struct alsa_write_args_info *conf
384 = para_calloc(sizeof(struct alsa_write_args_info));
385
386 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
387 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
388 if (ret)
389 goto err_out;
390 PARA_INFO_LOG("help given: %d\n", conf->help_given);
391 return conf;
392 err_out:
393 free(conf);
394 return NULL;
395 }
396
397 static void alsa_free_config(void *conf)
398 {
399 alsa_cmdline_parser_free(conf);
400 }
401
402 /**
403 * The init function of the alsa writer.
404 *
405 * \param w Pointer to the writer to initialize.
406 *
407 * \sa \ref struct writer.
408 */
409 void alsa_write_init(struct writer *w)
410 {
411 struct alsa_write_args_info dummy;
412
413 alsa_cmdline_parser_init(&dummy);
414 w->open = alsa_open;
415 w->close = alsa_close;
416 w->pre_select = alsa_write_pre_select;
417 w->pre_select_btr = alsa_write_pre_select_btr;
418 w->post_select = alsa_write_post_select;
419 w->post_select_btr = alsa_write_post_select_btr;
420 w->parse_config = alsa_parse_config;
421 w->shutdown = NULL; /* nothing to do */
422 w->free_config = alsa_free_config;
423 w->help = (struct ggo_help) {
424 .short_help = alsa_write_args_info_help,
425 .detailed_help = alsa_write_args_info_detailed_help
426 };
427 alsa_cmdline_parser_free(&dummy);
428 }