alsa: Kill unnecessary -B option.
[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 if (wn->btrn)
163 return alsa_open_btr(wn);
164 return alsa_open_nobtr(wn);
165 }
166
167 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
168 {
169 struct private_alsa_write_data *pad = wn->private_data;
170 struct writer_node_group *wng = wn->wng;
171 struct timeval tv;
172 snd_pcm_sframes_t avail, underrun;
173
174 if (!pad->handle)
175 return 1;
176 if (wn->btrn) {
177 size_t sz = btr_get_input_queue_size(wn->btrn);
178 if (sz < pad->bytes_per_frame)
179 return 1;
180 } else {
181 if (*wng->loaded - wn->written < pad->bytes_per_frame)
182 return 1;
183 }
184 /*
185 * Data is available to be written to the alsa handle. Compute number
186 * of milliseconds until next buffer underrun would occur.
187 *
188 * snd_pcm_avail_update() updates the current available count of
189 * samples for writing. It is a light method to obtain current stream
190 * position, because it does not require the user <-> kernel context
191 * switch, but the value is less accurate, because ring buffer pointers
192 * are updated in kernel drivers only when an interrupt occurs.
193 */
194 avail = snd_pcm_avail_update(pad->handle);
195 if (avail < 0)
196 avail = 0;
197 underrun = (pad->buffer_frames - avail) * pad->buffer_time
198 / pad->buffer_frames / 1000;
199 if (underrun < 50)
200 underrun = 50;
201 underrun -= 50;
202 ms2tv(underrun, &tv);
203 if (tv_diff(&s->timeout, &tv, NULL) > 0)
204 s->timeout = tv;
205 //PARA_CRIT_LOG("timout: %lu\n", tv2ms(&s->timeout));
206 return 1;
207 }
208
209 static void alsa_write_pre_select_btr(struct sched *s, struct task *t)
210 {
211 struct writer_node *wn = container_of(t, struct writer_node, task);
212 t->error = alsa_write_pre_select(s, wn);
213 }
214
215 static void xrun(snd_pcm_t *handle)
216 {
217 snd_pcm_status_t *status;
218 int ret;
219 struct timeval tv, diff;
220
221 snd_pcm_status_alloca(&status);
222 ret = snd_pcm_status(handle, status);
223 if (ret < 0)
224 return;
225 if (snd_pcm_status_get_state(status) != SND_PCM_STATE_XRUN)
226 return;
227 snd_pcm_status_get_trigger_tstamp(status, &tv);
228 tv_diff(now, &tv, &diff);
229 PARA_WARNING_LOG("underrun: %lums\n", tv2ms(&diff));
230 }
231
232 static int alsa_write_post_select(__a_unused struct sched *s,
233 struct writer_node *wn)
234 {
235 struct private_alsa_write_data *pad = wn->private_data;
236 struct writer_node_group *wng = wn->wng;
237 size_t bytes = *wng->loaded - wn->written;
238 unsigned char *data = (unsigned char*)*wng->bufp + wn->written;
239 snd_pcm_sframes_t ret, frames, avail;
240
241 if (*wng->input_error < 0 && (!pad->handle || bytes < pad->bytes_per_frame)) {
242 wn->written = *wng->loaded;
243 return *wng->input_error;
244 }
245 if (!bytes) /* no data available */
246 return 0;
247 if (!pad->handle) {
248 int err = alsa_init(pad, wn->conf);
249 if (err < 0)
250 return err;
251 }
252 frames = bytes / pad->bytes_per_frame;
253 if (!frames) /* less than a single frame available */
254 return 0;
255 avail = snd_pcm_avail_update(pad->handle);
256 if (avail <= 0)
257 return 0;
258 frames = PARA_MIN(frames, avail);
259 ret = snd_pcm_writei(pad->handle, data, frames);
260 if (ret >= 0) {
261 wn->written += ret * pad->bytes_per_frame;
262 return 1;
263 }
264 if (ret == -EPIPE) {
265 xrun(pad->handle);
266 snd_pcm_prepare(pad->handle);
267 return 0;
268 }
269 PARA_WARNING_LOG("%s\n", snd_strerror(-ret));
270 if (ret == -EAGAIN)
271 return 0;
272 return -E_ALSA_WRITE;
273 }
274
275 static void alsa_close(struct writer_node *wn)
276 {
277 struct private_alsa_write_data *pad = wn->private_data;
278 PARA_INFO_LOG("closing writer node %p\n", wn);
279
280 if (pad->handle) {
281 snd_pcm_drain(pad->handle);
282 snd_pcm_close(pad->handle);
283 snd_config_update_free_global();
284 }
285 free(pad);
286 }
287
288 static void alsa_write_post_select_btr(__a_unused struct sched *s,
289 struct task *t)
290 {
291 struct writer_node *wn = container_of(t, struct writer_node, task);
292 struct private_alsa_write_data *pad = wn->private_data;
293 char *data;
294 size_t bytes;
295 snd_pcm_sframes_t frames, avail;
296 int ret;
297
298 again:
299 bytes = btr_next_buffer(wn->btrn, &data);
300 //PARA_CRIT_LOG("have: %zu\n", bytes);
301 t->error = 0;
302 ret = -E_ALSA_ORPHAN;
303 if (btr_no_parent(wn->btrn) && (!pad->handle || bytes < pad->bytes_per_frame))
304 goto err;
305 if (!pad->handle) {
306 char *buf;
307 struct alsa_write_args_info *conf = wn->conf;
308 if (bytes == 0) /* no data available */
309 return;
310 PARA_CRIT_LOG("alsa init\n");
311 /* defaults */
312 pad->samplerate = conf->samplerate_arg;
313 pad->channels = conf->channels_arg;
314 if (!conf->samplerate_given) { /* config option trumps btr_exec */
315 /* ask parent btr nodes */
316 buf = NULL;
317 ret = btr_exec_up(wn->btrn, "samplerate", &buf);
318 PARA_CRIT_LOG("ret: %d\n", ret);
319 if (ret >= 0) {
320 int32_t rate;
321
322 ret = para_atoi32(buf, &rate);
323 free(buf);
324 if (ret < 0) /* should not happen */
325 goto err;
326 pad->samplerate = rate;
327 }
328 }
329 if (!conf->channels_given) {
330 buf = NULL;
331 ret = btr_exec_up(wn->btrn, "channels", &buf);
332 if (ret >= 0) {
333 int32_t ch;
334
335 ret = para_atoi32(buf, &ch);
336 freep(&buf);
337 if (ret < 0)
338 goto err;
339 pad->channels = ch;
340 }
341 }
342 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
343 ret = 1;
344 ret = alsa_init(pad, wn->conf);
345 if (ret < 0)
346 goto err;
347 }
348 for (;;) {
349 if (bytes == 0)
350 return;
351 if (bytes >= pad->bytes_per_frame)
352 break;
353 /* should not be possible to reach this */
354 PARA_CRIT_LOG("dropping %zu byte buffer\n", bytes);
355 btr_consume(wn->btrn, bytes);
356 bytes = btr_next_buffer(wn->btrn, &data);
357 }
358 frames = bytes / pad->bytes_per_frame;
359 avail = snd_pcm_avail_update(pad->handle);
360 if (avail <= 0)
361 return;
362 frames = PARA_MIN(frames, avail);
363 //PARA_CRIT_LOG("writing %ld frames\n", frames);
364 frames = snd_pcm_writei(pad->handle, data, frames);
365 if (frames >= 0) {
366 btr_consume(wn->btrn, frames * pad->bytes_per_frame);
367 goto again;
368 }
369 if (frames == -EPIPE) {
370 xrun(pad->handle);
371 snd_pcm_prepare(pad->handle);
372 return;
373 }
374 PARA_WARNING_LOG("%s\n", snd_strerror(-frames));
375 if (frames == -EAGAIN)
376 return;
377 ret = -E_ALSA_WRITE;
378 err:
379 assert(ret < 0);
380 alsa_close(wn);
381 btr_del_node(wn->btrn);
382 wn->btrn = NULL;
383 t->error = ret;
384 }
385
386 __malloc static void *alsa_parse_config(const char *options)
387 {
388 int ret;
389 struct alsa_write_args_info *conf
390 = para_calloc(sizeof(struct alsa_write_args_info));
391
392 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
393 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
394 if (ret)
395 goto err_out;
396 PARA_INFO_LOG("help given: %d\n", conf->help_given);
397 return conf;
398 err_out:
399 free(conf);
400 return NULL;
401 }
402
403 /**
404 * the init function of the alsa writer
405 *
406 * \param w pointer to the writer to initialize
407 *
408 * \sa struct writer
409 */
410 void alsa_write_init(struct writer *w)
411 {
412 struct alsa_write_args_info dummy;
413
414 alsa_cmdline_parser_init(&dummy);
415 w->open = alsa_open;
416 w->close = alsa_close;
417 w->pre_select = alsa_write_pre_select;
418 w->pre_select_btr = alsa_write_pre_select_btr;
419 w->post_select = alsa_write_post_select;
420 w->post_select_btr = alsa_write_post_select_btr;
421 w->parse_config = alsa_parse_config;
422 w->shutdown = NULL; /* nothing to do */
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 }