Alsa improvement and fixes.
[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 err = snd_pcm_open(&pad->handle, conf->device_arg,
70 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
71 if (err < 0)
72 return -E_PCM_OPEN;
73
74 snd_pcm_hw_params_alloca(&hwparams);
75 snd_pcm_sw_params_alloca(&swparams);
76 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
77 return -E_BROKEN_CONF;
78 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
79 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
80 return -E_ACCESS_TYPE;
81 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
82 return -E_SAMPLE_FORMAT;
83 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
84 pad->channels) < 0)
85 return -E_CHANNEL_COUNT;
86 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
87 &pad->samplerate, NULL) < 0)
88 return -E_SET_RATE;
89 err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
90 &pad->buffer_time, NULL);
91 if (err < 0 || !pad->buffer_time)
92 return -E_GET_BUFFER_TIME;
93 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
94 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
95 &pad->buffer_time, NULL) < 0)
96 return -E_SET_BUFFER_TIME;
97 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
98 return -E_HW_PARAMS;
99 snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
100 snd_pcm_hw_params_get_buffer_size(hwparams, &pad->buffer_frames);
101 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", pad->buffer_frames,
102 period_size);
103 if (period_size == pad->buffer_frames)
104 return -E_BAD_PERIOD;
105 snd_pcm_sw_params_current(pad->handle, swparams);
106 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
107 if (pad->buffer_frames < 1)
108 start_threshold = 1;
109 else
110 start_threshold = PARA_MIN(pad->buffer_frames,
111 (snd_pcm_uframes_t)pad->samplerate);
112 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
113 start_threshold) < 0)
114 return -E_START_THRESHOLD;
115 stop_threshold = pad->buffer_frames;
116 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
117 stop_threshold) < 0)
118 return -E_STOP_THRESHOLD;
119 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
120 PARA_WARNING_LOG("unable to install sw params\n");
121 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
122 * pad->channels / 8;
123 if (pad->bytes_per_frame <= 0)
124 return -E_PHYSICAL_WIDTH;
125 PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
126 if (snd_pcm_nonblock(pad->handle, 1))
127 PARA_ERROR_LOG("failed to set nonblock mode\n");
128 return 1;
129 }
130
131 /* Open an instance of the alsa writer. */
132 static int alsa_open_nobtr(struct writer_node *wn)
133 {
134 struct alsa_write_args_info *conf = wn->conf;
135 struct writer_node_group *wng = wn->wng;
136 struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
137
138 wn->private_data = pad;
139 if (!conf->samplerate_given && wng->samplerate)
140 pad->samplerate = *wng->samplerate;
141 else
142 pad->samplerate = conf->samplerate_arg;
143 if (!conf->channels_given && wng->channels)
144 pad->channels = *wng->channels;
145 else
146 pad->channels = conf->channels_arg;
147 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
148 return 1;
149 }
150
151 static int alsa_open_btr(struct writer_node *wn)
152 {
153 struct private_alsa_write_data *pad = para_calloc(sizeof(*pad));
154
155 sprintf(wn->task.status, "alsa writer");
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 size_t sz = btr_get_input_queue_size(wn->btrn);
177 if (sz < pad->bytes_per_frame) {
178 if (!btr_no_parent(wn->btrn))
179 return 1;
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 t->error = 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 = prepare_writer_node(wn);
311 if (ret == 0)
312 return;
313 bytes = btr_next_buffer(btrn, &data);
314 if (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 return;
324 }
325 if (!pad->handle) {
326 char *buf;
327 struct alsa_write_args_info *conf = wn->conf;
328 if (bytes == 0) /* no data available */
329 return;
330 PARA_CRIT_LOG("alsa init\n");
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 /* ask parent btr nodes */
336 buf = NULL;
337 ret = btr_exec_up(btrn, "samplerate", &buf);
338 PARA_CRIT_LOG("ret: %d\n", ret);
339 if (ret >= 0) {
340 int32_t rate;
341
342 ret = para_atoi32(buf, &rate);
343 free(buf);
344 if (ret < 0) /* should not happen */
345 goto err;
346 pad->samplerate = rate;
347 }
348 }
349 if (!conf->channels_given) {
350 buf = NULL;
351 ret = btr_exec_up(btrn, "channels", &buf);
352 if (ret >= 0) {
353 int32_t ch;
354
355 ret = para_atoi32(buf, &ch);
356 freep(&buf);
357 if (ret < 0)
358 goto err;
359 pad->channels = ch;
360 }
361 }
362 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
363 ret = 1;
364 ret = alsa_init(pad, wn->conf);
365 if (ret < 0)
366 goto err;
367 wn->min_iqs = pad->bytes_per_frame;
368 }
369 frames = bytes / pad->bytes_per_frame;
370 avail = snd_pcm_avail_update(pad->handle);
371 if (avail <= 0)
372 return;
373 frames = PARA_MIN(frames, avail);
374 //PARA_CRIT_LOG("writing %ld frames\n", frames);
375 frames = snd_pcm_writei(pad->handle, data, frames);
376 if (frames >= 0) {
377 btr_consume(btrn, frames * pad->bytes_per_frame);
378 goto again;
379 }
380 if (frames == -EPIPE) {
381 xrun(pad->handle);
382 snd_pcm_prepare(pad->handle);
383 return;
384 }
385 PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
386 if (frames == -EAGAIN)
387 return;
388 ret = -E_ALSA_WRITE;
389 err:
390 assert(ret < 0);
391 btr_del_node(btrn);
392 alsa_close(wn);
393 t->error = ret;
394 }
395
396 __malloc static void *alsa_parse_config(const char *options)
397 {
398 int ret;
399 struct alsa_write_args_info *conf
400 = para_calloc(sizeof(struct alsa_write_args_info));
401
402 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
403 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
404 if (ret)
405 goto err_out;
406 PARA_INFO_LOG("help given: %d\n", conf->help_given);
407 return conf;
408 err_out:
409 free(conf);
410 return NULL;
411 }
412
413 /**
414 * the init function of the alsa writer
415 *
416 * \param w pointer to the writer to initialize
417 *
418 * \sa struct writer
419 */
420 void alsa_write_init(struct writer *w)
421 {
422 struct alsa_write_args_info dummy;
423
424 alsa_cmdline_parser_init(&dummy);
425 w->open = alsa_open;
426 w->close = alsa_close;
427 w->pre_select = alsa_write_pre_select;
428 w->pre_select_btr = alsa_write_pre_select_btr;
429 w->post_select = alsa_write_post_select;
430 w->post_select_btr = alsa_write_post_select_btr;
431 w->parse_config = alsa_parse_config;
432 w->shutdown = NULL; /* nothing to do */
433 w->help = (struct ggo_help) {
434 .short_help = alsa_write_args_info_help,
435 .detailed_help = alsa_write_args_info_detailed_help
436 };
437 alsa_cmdline_parser_free(&dummy);
438 }