5959545f81e706ad3ebaa34ffb83104d139ca5fb
[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 "alsa_write.cmdline.h"
31 #include "error.h"
32
33 /** always use 16 bit little endian */
34 #define FORMAT SND_PCM_FORMAT_S16_LE
35
36 /** Data specific to the alsa writer. */
37 struct private_alsa_write_data {
38 /** The alsa handle */
39 snd_pcm_t *handle;
40 /** Determined and set by alsa_open(). */
41 int bytes_per_frame;
42 /** The approximate maximum buffer duration in us. */
43 unsigned buffer_time;
44 /* Number of frames that fit into the buffer. */
45 unsigned buffer_frames;
46 /**
47 * The samplerate given by command line option or the decoder
48 * of the writer node group.
49 */
50 unsigned samplerate;
51 /**
52 * The number of channels, given by command line option or the
53 * decoder of the writer node group.
54 */
55 unsigned channels;
56 };
57
58 /* Install PCM software and hardware configuration. */
59 static int alsa_init(struct private_alsa_write_data *pad,
60 struct alsa_write_args_info *conf)
61 {
62 snd_pcm_hw_params_t *hwparams;
63 snd_pcm_sw_params_t *swparams;
64 snd_pcm_uframes_t buffer_size, start_threshold, stop_threshold;
65 snd_pcm_uframes_t period_size;
66 int err;
67
68 err = snd_pcm_open(&pad->handle, conf->device_arg,
69 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
70 if (err < 0)
71 return -E_PCM_OPEN;
72
73 snd_pcm_hw_params_alloca(&hwparams);
74 snd_pcm_sw_params_alloca(&swparams);
75 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
76 return -E_BROKEN_CONF;
77 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
78 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
79 return -E_ACCESS_TYPE;
80 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
81 return -E_SAMPLE_FORMAT;
82 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
83 pad->channels) < 0)
84 return -E_CHANNEL_COUNT;
85 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
86 &pad->samplerate, NULL) < 0)
87 return -E_SET_RATE;
88 err = snd_pcm_hw_params_get_buffer_time_max(hwparams,
89 &pad->buffer_time, NULL);
90 if (err < 0 || !pad->buffer_time)
91 return -E_GET_BUFFER_TIME;
92 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
93 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
94 &pad->buffer_time, NULL) < 0)
95 return -E_SET_BUFFER_TIME;
96 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
97 return -E_HW_PARAMS;
98 snd_pcm_hw_params_get_period_size(hwparams, &period_size, NULL);
99 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
100 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
101 period_size);
102 if (period_size == buffer_size)
103 return -E_BAD_PERIOD;
104 snd_pcm_sw_params_current(pad->handle, swparams);
105 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
106 if (buffer_size < 1)
107 start_threshold = 1;
108 else
109 start_threshold = PARA_MIN(buffer_size,
110 (snd_pcm_uframes_t)pad->samplerate);
111 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
112 start_threshold) < 0)
113 return -E_START_THRESHOLD;
114 stop_threshold = buffer_size;
115 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
116 stop_threshold) < 0)
117 return -E_STOP_THRESHOLD;
118 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
119 PARA_WARNING_LOG("unable to install sw params\n");
120 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
121 * pad->channels / 8;
122 if (pad->bytes_per_frame <= 0)
123 return -E_PHYSICAL_WIDTH;
124 PARA_INFO_LOG("bytes per frame: %d\n", pad->bytes_per_frame);
125 if (snd_pcm_nonblock(pad->handle, 1))
126 PARA_ERROR_LOG("failed to set nonblock mode\n");
127 pad->buffer_frames = 1000 * pad->buffer_time / pad->samplerate;
128 PARA_INFO_LOG("max buffered frames: %d\n", pad->buffer_frames);
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 sprintf(wn->task.status, "alsa writer");
157 wn->private_data = pad;
158 return 1;
159 }
160 static int alsa_open(struct writer_node *wn)
161 {
162 struct alsa_write_args_info *conf = wn->conf;
163
164 if (conf->buffer_tree_given)
165 return alsa_open_btr(wn);
166 else
167 return alsa_open_nobtr(wn);
168
169 }
170
171 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
172 {
173 struct alsa_write_args_info *conf = wn->conf;
174 struct private_alsa_write_data *pad = wn->private_data;
175 struct writer_node_group *wng = wn->wng;
176 struct timeval tv;
177 snd_pcm_sframes_t avail, underrun;
178
179 if (!pad->handle)
180 return 1;
181 if (conf->buffer_tree_given) {
182 size_t sz = btr_get_input_queue_size(wn->btrn);
183 if (sz < pad->bytes_per_frame)
184 return 1;
185 } else {
186 if (*wng->loaded - wn->written < pad->bytes_per_frame)
187 return 1;
188 }
189 /*
190 * Data is available to be written to the alsa handle. Compute number
191 * of milliseconds until next buffer underrun would occur.
192 *
193 * snd_pcm_avail_update() updates the current available count of
194 * samples for writing. It is a light method to obtain current stream
195 * position, because it does not require the user <-> kernel context
196 * switch, but the value is less accurate, because ring buffer pointers
197 * are updated in kernel drivers only when an interrupt occurs.
198 */
199 avail = snd_pcm_avail_update(pad->handle);
200 if (avail < 0)
201 avail = 0;
202 underrun = (pad->buffer_frames - avail) * pad->buffer_time
203 / pad->buffer_frames / 1000;
204 if (underrun < 50)
205 underrun = 50;
206 underrun -= 50;
207 ms2tv(underrun, &tv);
208 if (tv_diff(&s->timeout, &tv, NULL) > 0)
209 s->timeout = tv;
210 //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
211 return 1;
212 }
213
214 static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
215 {
216 struct writer_node *wn = container_of(t, struct writer_node, task);
217 t->error = alsa_write_pre_select(s, wn);
218 }
219
220 static void xrun(snd_pcm_t *handle)
221 {
222 snd_pcm_status_t *status;
223 int ret;
224 struct timeval tv, diff;
225
226 snd_pcm_status_alloca(&status);
227 ret = snd_pcm_status(handle, status);
228 if (ret < 0)
229 return;
230 if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
231 return;
232 snd_pcm_status_get_trigger_tstamp(status, &tv);
233 tv_diff(now, &tv, &diff);
234 PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
235 }
236
237 static int alsa_write_post_select(__a_unused struct sched *s,
238 struct writer_node *wn)
239 {
240 struct private_alsa_write_data *pad = wn->private_data;
241 struct writer_node_group *wng = wn->wng;
242 size_t bytes = *wng->loaded - wn->written;
243 unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
244 snd_pcm_sframes_t ret, frames, avail;
245
246 if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
247 wn->written = *wng->loaded;
248 return *wng->input_error;
249 }
250 if (!bytes) /* no data available */
251 return 0;
252 if (!pad->handle) {
253 int err = alsa_init(pad, wn->conf);
254 if (err < 0)
255 return err;
256 }
257 frames = bytes / pad->bytes_per_frame;
258 if (!frames) /* less than a single frame available */
259 return 0;
260 avail = snd_pcm_avail_update(pad->handle);
261 if (avail <= 0)
262 return 0;
263 frames = PARA_MIN(frames, avail);
264 ret = snd_pcm_writei(pad->handle, data, frames);
265 if (ret >= 0) {
266 wn->written += ret * pad->bytes_per_frame;
267 return 1;
268 }
269 if (ret == -EPIPE) {
270 xrun(pad->handle);
271 snd_pcm_prepare(pad->handle);
272 return 0;
273 }
274 PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
275 if (ret == -EAGAIN)
276 return 0;
277 return -E_ALSA_WRITE;
278 }
279
280 static void alsa_close(struct writer_node *wn)
281 {
282 struct private_alsa_write_data *pad = wn->private_data;
283 PARA_INFO_LOG("closing writer node %p\n", wn);
284
285 if (pad->handle) {
286 snd_pcm_drain(pad->handle);
287 snd_pcm_close(pad->handle);
288 snd_config_update_free_global();
289 }
290 free(pad);
291 }
292
293 static void alsa_write_post_select_btr(__a_unused struct sched *s,
294 struct task *t)
295 {
296 struct writer_node *wn = container_of(t, struct writer_node, task);
297 struct private_alsa_write_data *pad = wn->private_data;
298 char *data;
299 size_t bytes;
300 snd_pcm_sframes_t frames, avail;
301 int ret;
302
303 again:
304 bytes = btr_next_buffer(wn->btrn, &data);
305 //PARA_CRIT_LOG("have: %zu\n", bytes);
306 t->error = 0;
307 ret = -E_ALSA_ORPHAN;
308 if (btr_no_parent(wn->btrn) && (!pad->handle || bytes < pad->bytes_per_frame))
309 goto err;
310 if (!pad->handle) {
311 char *buf;
312 struct alsa_write_args_info *conf = wn->conf;
313 if (bytes == 0) /* no data available */
314 return;
315 PARA_CRIT_LOG("alsa init\n");
316 /* defaults */
317 pad->samplerate = conf->samplerate_arg;
318 pad->channels = conf->channels_arg;
319 if (!conf->samplerate_given) { /* config option trumps btr_exec */
320 /* ask parent btr nodes */
321 buf = NULL;
322 ret = btr_exec_up(wn->btrn, "samplerate", &buf);
323 PARA_CRIT_LOG("ret: %d\n", ret);
324 if (ret >= 0) {
325 int32_t rate;
326
327 ret = para_atoi32(buf, &rate);
328 free(buf);
329 if (ret < 0) /* should not happen */
330 goto err;
331 pad->samplerate = rate;
332 }
333 }
334 if (!conf->channels_given) {
335 buf = NULL;
336 ret = btr_exec_up(wn->btrn, "channels", &buf);
337 if (ret >= 0) {
338 int32_t ch;
339
340 ret = para_atoi32(buf, &ch);
341 freep(&buf);
342 if (ret < 0)
343 goto err;
344 pad->channels = ch;
345 }
346 }
347 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
348 ret = 1;
349 ret = alsa_init(pad, wn->conf);
350 if (ret < 0)
351 goto err;
352 }
353 for (;;) {
354 if (bytes == 0)
355 return;
356 if (bytes >= pad->bytes_per_frame)
357 break;
358 /* should not be possible to reach this */
359 PARA_CRIT_LOG("dropping %zu byte buffer\n", bytes);
360 btr_consume(wn->btrn, bytes);
361 bytes = btr_next_buffer(wn->btrn, &data);
362 }
363 frames = bytes / pad->bytes_per_frame;
364 avail = snd_pcm_avail_update(pad->handle);
365 if (avail <= 0)
366 return;
367 frames = PARA_MIN(frames, avail);
368 //PARA_CRIT_LOG("writing %ld frames\n", frames);
369 frames = snd_pcm_writei(pad->handle, data, frames);
370 if (frames >= 0) {
371 btr_consume(wn->btrn, frames * pad->bytes_per_frame);
372 goto again;
373 }
374 if (frames == -EPIPE) {
375 xrun(pad->handle);
376 snd_pcm_prepare(pad->handle);
377 return;
378 }
379 PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
380 if (frames == -EAGAIN)
381 return;
382 ret = -E_ALSA_WRITE;
383 err:
384 assert(ret < 0);
385 alsa_close(wn);
386 btr_del_node(wn->btrn);
387 wn->btrn = NULL;
388 t->error = ret;
389 }
390
391 __malloc static void *alsa_parse_config(const char *options)
392 {
393 int ret;
394 struct alsa_write_args_info *conf
395 = para_calloc(sizeof(struct alsa_write_args_info));
396
397 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
398 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
399 if (ret)
400 goto err_out;
401 PARA_INFO_LOG("help given: %d\n", conf->help_given);
402 return conf;
403 err_out:
404 free(conf);
405 return NULL;
406 }
407
408 /**
409 * the init function of the alsa writer
410 *
411 * \param w pointer to the writer to initialize
412 *
413 * \sa struct writer
414 */
415 void alsa_write_init(struct writer *w)
416 {
417 struct alsa_write_args_info dummy;
418
419 alsa_cmdline_parser_init(&dummy);
420 w->open = alsa_open;
421 w->close = alsa_close;
422 w->pre_select = alsa_write_pre_select;
423 w->pre_select_btr = alsa_write_pre_select_btr;
424 w->post_select = alsa_write_post_select;
425 w->post_select_btr = alsa_write_post_select_btr;
426 w->parse_config = alsa_parse_config;
427 w->shutdown = NULL; /* nothing to do */
428 w->help = (struct ggo_help) {
429 .short_help = alsa_write_args_info_help,
430 .detailed_help = alsa_write_args_info_detailed_help
431 };
432 alsa_cmdline_parser_free(&dummy);
433 }