2 * \file pcm/pcm_dsnoop.c
4 * \brief PCM Capture Stream Snooping (dsnoop) Plugin Interface
5 * \author Jaroslav Kysela <perex@suse.cz>
9 * PCM - Capture Stream Snooping
10 * Copyright (c) 2003 by Jaroslav Kysela <perex@suse.cz>
13 * This library is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU Lesser General Public License as
15 * published by the Free Software Foundation; either version 2.1 of
16 * the License, or (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU Lesser General Public License for more details.
23 * You should have received a copy of the GNU Lesser General Public
24 * License along with this library; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
37 #include <sys/ioctl.h>
42 #include <sys/socket.h>
45 #include "pcm_direct.h"
48 /* entry for static linking */
49 const char *_snd_module_pcm_dsnoop = "";
56 static void snoop_areas(snd_pcm_direct_t *dsnoop,
57 const snd_pcm_channel_area_t *src_areas,
58 const snd_pcm_channel_area_t *dst_areas,
59 snd_pcm_uframes_t src_ofs,
60 snd_pcm_uframes_t dst_ofs,
61 snd_pcm_uframes_t size)
63 unsigned int chn, schn, channels;
64 snd_pcm_format_t format;
66 channels = dsnoop->channels;
67 format = dsnoop->shmptr->s.format;
68 if (dsnoop->interleaved) {
69 unsigned int fbytes = snd_pcm_format_physical_width(format) / 8;
70 memcpy(((char *)dst_areas[0].addr) + (dst_ofs * channels * fbytes),
71 ((char *)src_areas[0].addr) + (src_ofs * channels * fbytes),
72 size * channels * fbytes);
74 for (chn = 0; chn < channels; chn++) {
75 schn = dsnoop->bindings ? dsnoop->bindings[chn] : chn;
76 snd_pcm_area_copy(&dst_areas[chn], dst_ofs, &src_areas[schn], src_ofs, size, format);
82 * synchronize shm ring buffer with hardware
84 static void snd_pcm_dsnoop_sync_area(snd_pcm_t *pcm, snd_pcm_uframes_t slave_hw_ptr, snd_pcm_uframes_t size)
86 snd_pcm_direct_t *dsnoop = pcm->private_data;
87 snd_pcm_uframes_t hw_ptr = dsnoop->hw_ptr;
88 snd_pcm_uframes_t transfer;
89 const snd_pcm_channel_area_t *src_areas, *dst_areas;
91 /* add sample areas here */
92 dst_areas = snd_pcm_mmap_areas(pcm);
93 src_areas = snd_pcm_mmap_areas(dsnoop->spcm);
94 hw_ptr %= pcm->buffer_size;
95 slave_hw_ptr %= dsnoop->shmptr->s.buffer_size;
97 transfer = hw_ptr + size > pcm->buffer_size ? pcm->buffer_size - hw_ptr : size;
98 transfer = slave_hw_ptr + transfer > dsnoop->shmptr->s.buffer_size ? dsnoop->shmptr->s.buffer_size - slave_hw_ptr : transfer;
100 snoop_areas(dsnoop, src_areas, dst_areas, slave_hw_ptr, hw_ptr, transfer);
101 slave_hw_ptr += transfer;
102 slave_hw_ptr %= dsnoop->shmptr->s.buffer_size;
104 hw_ptr %= pcm->buffer_size;
109 * synchronize hardware pointer (hw_ptr) with ours
111 static snd_pcm_sframes_t snd_pcm_dsnoop_sync_ptr(snd_pcm_t *pcm)
113 snd_pcm_direct_t *dsnoop = pcm->private_data;
114 snd_pcm_uframes_t slave_hw_ptr, old_slave_hw_ptr, avail;
115 snd_pcm_sframes_t diff;
117 old_slave_hw_ptr = dsnoop->slave_hw_ptr;
118 slave_hw_ptr = dsnoop->slave_hw_ptr = *dsnoop->spcm->hw.ptr;
119 diff = slave_hw_ptr - old_slave_hw_ptr;
120 if (diff == 0) /* fast path */
123 slave_hw_ptr += dsnoop->shmptr->s.boundary;
124 diff = slave_hw_ptr - old_slave_hw_ptr;
126 snd_pcm_dsnoop_sync_area(pcm, old_slave_hw_ptr, diff);
127 dsnoop->hw_ptr += diff;
128 dsnoop->hw_ptr %= pcm->boundary;
129 // printf("sync ptr diff = %li\n", diff);
130 if (pcm->stop_threshold >= pcm->boundary) /* don't care */
132 if ((avail = snd_pcm_mmap_capture_hw_avail(pcm)) >= pcm->stop_threshold) {
134 gettimeofday(&tv, 0);
135 dsnoop->trigger_tstamp.tv_sec = tv.tv_sec;
136 dsnoop->trigger_tstamp.tv_nsec = tv.tv_usec * 1000L;
137 dsnoop->state = SND_PCM_STATE_XRUN;
138 dsnoop->avail_max = avail;
141 if (avail > dsnoop->avail_max)
142 dsnoop->avail_max = avail;
147 * plugin implementation
150 static int snd_pcm_dsnoop_status(snd_pcm_t *pcm, snd_pcm_status_t * status)
152 snd_pcm_direct_t *dsnoop = pcm->private_data;
154 switch(dsnoop->state) {
155 case SNDRV_PCM_STATE_DRAINING:
156 case SNDRV_PCM_STATE_RUNNING:
157 snd_pcm_dsnoop_sync_ptr(pcm);
162 memset(status, 0, sizeof(*status));
163 status->state = dsnoop->state;
164 status->trigger_tstamp = dsnoop->trigger_tstamp;
165 status->tstamp = snd_pcm_hw_fast_tstamp(dsnoop->spcm);
166 status->avail = snd_pcm_mmap_capture_avail(pcm);
167 status->avail_max = status->avail > dsnoop->avail_max ? status->avail : dsnoop->avail_max;
168 dsnoop->avail_max = 0;
172 static snd_pcm_state_t snd_pcm_dsnoop_state(snd_pcm_t *pcm)
174 snd_pcm_direct_t *dsnoop = pcm->private_data;
175 return dsnoop->state;
178 static int snd_pcm_dsnoop_delay(snd_pcm_t *pcm, snd_pcm_sframes_t *delayp)
180 snd_pcm_direct_t *dsnoop = pcm->private_data;
183 switch(dsnoop->state) {
184 case SNDRV_PCM_STATE_DRAINING:
185 case SNDRV_PCM_STATE_RUNNING:
186 err = snd_pcm_dsnoop_sync_ptr(pcm);
189 case SNDRV_PCM_STATE_PREPARED:
190 case SNDRV_PCM_STATE_SUSPENDED:
191 *delayp = snd_pcm_mmap_capture_hw_avail(pcm);
193 case SNDRV_PCM_STATE_XRUN:
200 static int snd_pcm_dsnoop_hwsync(snd_pcm_t *pcm)
202 snd_pcm_direct_t *dsnoop = pcm->private_data;
204 switch(dsnoop->state) {
205 case SNDRV_PCM_STATE_DRAINING:
206 case SNDRV_PCM_STATE_RUNNING:
207 return snd_pcm_dsnoop_sync_ptr(pcm);
208 case SNDRV_PCM_STATE_PREPARED:
209 case SNDRV_PCM_STATE_SUSPENDED:
211 case SNDRV_PCM_STATE_XRUN:
218 static int snd_pcm_dsnoop_prepare(snd_pcm_t *pcm)
220 snd_pcm_direct_t *dsnoop = pcm->private_data;
222 snd_pcm_direct_check_interleave(dsnoop, pcm);
223 // assert(pcm->boundary == dsnoop->shmptr->s.boundary); /* for sure */
224 dsnoop->state = SND_PCM_STATE_PREPARED;
225 dsnoop->appl_ptr = 0;
230 static int snd_pcm_dsnoop_reset(snd_pcm_t *pcm)
232 snd_pcm_direct_t *dsnoop = pcm->private_data;
233 dsnoop->hw_ptr %= pcm->period_size;
234 dsnoop->appl_ptr = dsnoop->hw_ptr;
235 dsnoop->slave_appl_ptr = dsnoop->slave_hw_ptr = *dsnoop->spcm->hw.ptr;
239 static int snd_pcm_dsnoop_start(snd_pcm_t *pcm)
241 snd_pcm_direct_t *dsnoop = pcm->private_data;
245 if (dsnoop->state != SND_PCM_STATE_PREPARED)
247 err = snd_timer_start(dsnoop->timer);
250 dsnoop->state = SND_PCM_STATE_RUNNING;
251 dsnoop->slave_appl_ptr = dsnoop->slave_hw_ptr = *dsnoop->spcm->hw.ptr;
252 gettimeofday(&tv, 0);
253 dsnoop->trigger_tstamp.tv_sec = tv.tv_sec;
254 dsnoop->trigger_tstamp.tv_nsec = tv.tv_usec * 1000L;
258 static int snd_pcm_dsnoop_drop(snd_pcm_t *pcm)
260 snd_pcm_direct_t *dsnoop = pcm->private_data;
261 if (dsnoop->state == SND_PCM_STATE_OPEN)
263 snd_timer_stop(dsnoop->timer);
264 dsnoop->state = SND_PCM_STATE_SETUP;
268 static int snd_pcm_dsnoop_drain(snd_pcm_t *pcm)
270 snd_pcm_direct_t *dsnoop = pcm->private_data;
271 snd_pcm_uframes_t stop_threshold;
274 if (dsnoop->state == SND_PCM_STATE_OPEN)
276 stop_threshold = pcm->stop_threshold;
277 if (pcm->stop_threshold > pcm->buffer_size)
278 pcm->stop_threshold = pcm->buffer_size;
279 while (dsnoop->state == SND_PCM_STATE_RUNNING) {
280 err = snd_pcm_dsnoop_sync_ptr(pcm);
283 if (pcm->mode & SND_PCM_NONBLOCK)
285 snd_pcm_wait(pcm, -1);
287 pcm->stop_threshold = stop_threshold;
288 return snd_pcm_dsnoop_drop(pcm);
291 static int snd_pcm_dsnoop_pause(snd_pcm_t *pcm, int enable)
293 snd_pcm_direct_t *dsnoop = pcm->private_data;
295 if (dsnoop->state != SND_PCM_STATE_RUNNING)
297 dsnoop->state = SND_PCM_STATE_PAUSED;
298 snd_timer_stop(dsnoop->timer);
300 if (dsnoop->state != SND_PCM_STATE_PAUSED)
302 dsnoop->state = SND_PCM_STATE_RUNNING;
303 snd_timer_start(dsnoop->timer);
308 static snd_pcm_sframes_t snd_pcm_dsnoop_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
310 snd_pcm_mmap_appl_backward(pcm, frames);
314 static snd_pcm_sframes_t snd_pcm_dsnoop_forward(snd_pcm_t *pcm, snd_pcm_uframes_t frames)
316 snd_pcm_sframes_t avail;
318 avail = snd_pcm_mmap_capture_hw_avail(pcm);
321 if (frames > (snd_pcm_uframes_t)avail)
323 snd_pcm_mmap_appl_forward(pcm, frames);
327 static int snd_pcm_dsnoop_resume(snd_pcm_t *pcm ATTRIBUTE_UNUSED)
329 // snd_pcm_direct_t *dsnoop = pcm->private_data;
334 static snd_pcm_sframes_t snd_pcm_dsnoop_writei(snd_pcm_t *pcm ATTRIBUTE_UNUSED, const void *buffer ATTRIBUTE_UNUSED, snd_pcm_uframes_t size ATTRIBUTE_UNUSED)
339 static snd_pcm_sframes_t snd_pcm_dsnoop_writen(snd_pcm_t *pcm ATTRIBUTE_UNUSED, void **bufs ATTRIBUTE_UNUSED, snd_pcm_uframes_t size ATTRIBUTE_UNUSED)
344 static int snd_pcm_dsnoop_close(snd_pcm_t *pcm)
346 snd_pcm_direct_t *dsnoop = pcm->private_data;
349 snd_timer_close(dsnoop->timer);
350 snd_pcm_direct_semaphore_down(dsnoop, DIRECT_IPC_SEM_CLIENT);
351 snd_pcm_close(dsnoop->spcm);
353 snd_pcm_direct_server_discard(dsnoop);
355 snd_pcm_direct_client_discard(dsnoop);
356 if (snd_pcm_direct_shm_discard(dsnoop) > 0) {
357 if (snd_pcm_direct_semaphore_discard(dsnoop) < 0)
358 snd_pcm_direct_semaphore_up(dsnoop, DIRECT_IPC_SEM_CLIENT);
360 snd_pcm_direct_semaphore_up(dsnoop, DIRECT_IPC_SEM_CLIENT);
362 if (dsnoop->bindings)
363 free(dsnoop->bindings);
364 pcm->private_data = NULL;
369 static snd_pcm_sframes_t snd_pcm_dsnoop_mmap_commit(snd_pcm_t *pcm,
370 snd_pcm_uframes_t offset ATTRIBUTE_UNUSED,
371 snd_pcm_uframes_t size)
373 snd_pcm_direct_t *dsnoop = pcm->private_data;
376 if (dsnoop->state == SND_PCM_STATE_RUNNING) {
377 err = snd_pcm_dsnoop_sync_ptr(pcm);
381 snd_pcm_mmap_appl_forward(pcm, size);
385 static snd_pcm_sframes_t snd_pcm_dsnoop_avail_update(snd_pcm_t *pcm ATTRIBUTE_UNUSED)
387 snd_pcm_direct_t *dsnoop = pcm->private_data;
390 if (dsnoop->state == SND_PCM_STATE_RUNNING) {
391 err = snd_pcm_dsnoop_sync_ptr(pcm);
395 return snd_pcm_mmap_capture_avail(pcm);
398 static void snd_pcm_dsnoop_dump(snd_pcm_t *pcm, snd_output_t *out)
400 snd_pcm_direct_t *dsnoop = pcm->private_data;
402 snd_output_printf(out, "Direct Stream Mixing PCM\n");
404 snd_output_printf(out, "\nIts setup is:\n");
405 snd_pcm_dump_setup(pcm, out);
408 snd_pcm_dump(dsnoop->spcm, out);
411 static snd_pcm_ops_t snd_pcm_dsnoop_ops = {
412 .close = snd_pcm_dsnoop_close,
413 .info = snd_pcm_direct_info,
414 .hw_refine = snd_pcm_direct_hw_refine,
415 .hw_params = snd_pcm_direct_hw_params,
416 .hw_free = snd_pcm_direct_hw_free,
417 .sw_params = snd_pcm_direct_sw_params,
418 .channel_info = snd_pcm_direct_channel_info,
419 .dump = snd_pcm_dsnoop_dump,
420 .nonblock = snd_pcm_direct_nonblock,
421 .async = snd_pcm_direct_async,
422 .poll_revents = snd_pcm_direct_poll_revents,
423 .mmap = snd_pcm_direct_mmap,
424 .munmap = snd_pcm_direct_munmap,
427 static snd_pcm_fast_ops_t snd_pcm_dsnoop_fast_ops = {
428 .status = snd_pcm_dsnoop_status,
429 .state = snd_pcm_dsnoop_state,
430 .hwsync = snd_pcm_dsnoop_hwsync,
431 .delay = snd_pcm_dsnoop_delay,
432 .prepare = snd_pcm_dsnoop_prepare,
433 .reset = snd_pcm_dsnoop_reset,
434 .start = snd_pcm_dsnoop_start,
435 .drop = snd_pcm_dsnoop_drop,
436 .drain = snd_pcm_dsnoop_drain,
437 .pause = snd_pcm_dsnoop_pause,
438 .rewind = snd_pcm_dsnoop_rewind,
439 .forward = snd_pcm_dsnoop_forward,
440 .resume = snd_pcm_dsnoop_resume,
441 .writei = snd_pcm_dsnoop_writei,
442 .writen = snd_pcm_dsnoop_writen,
443 .readi = snd_pcm_mmap_readi,
444 .readn = snd_pcm_mmap_readn,
445 .avail_update = snd_pcm_dsnoop_avail_update,
446 .mmap_commit = snd_pcm_dsnoop_mmap_commit,
450 * \brief Creates a new dsnoop PCM
451 * \param pcmp Returns created PCM handle
452 * \param name Name of PCM
453 * \param ipc_key IPC key for semaphore and shared memory
454 * \param ipc_perm IPC permissions for semaphore and shared memory
455 * \param params Parameters for slave
456 * \param root Configuration root
457 * \param sconf Slave configuration
458 * \param stream PCM Direction (stream)
459 * \param mode PCM Mode
460 * \retval zero on success otherwise a negative error code
461 * \warning Using of this function might be dangerous in the sense
462 * of compatibility reasons. The prototype might be freely
465 int snd_pcm_dsnoop_open(snd_pcm_t **pcmp, const char *name,
466 key_t ipc_key, mode_t ipc_perm,
467 struct slave_params *params,
468 snd_config_t *bindings,
469 snd_config_t *root, snd_config_t *sconf,
470 snd_pcm_stream_t stream, int mode)
472 snd_pcm_t *pcm = NULL, *spcm = NULL;
473 snd_pcm_direct_t *dsnoop = NULL;
474 int ret, first_instance, fail_sem_loop = 10;
478 if (stream != SND_PCM_STREAM_CAPTURE) {
479 SNDERR("The dsnoop plugin supports only capture stream");
483 dsnoop = calloc(1, sizeof(snd_pcm_direct_t));
489 ret = snd_pcm_direct_parse_bindings(dsnoop, bindings);
493 dsnoop->ipc_key = ipc_key;
494 dsnoop->ipc_perm = ipc_perm;
498 ret = snd_pcm_new(&pcm, dsnoop->type = SND_PCM_TYPE_DSNOOP, name, stream, mode);
503 ret = snd_pcm_direct_semaphore_create_or_connect(dsnoop);
505 SNDERR("unable to create IPC semaphore");
509 ret = snd_pcm_direct_semaphore_down(dsnoop, DIRECT_IPC_SEM_CLIENT);
511 snd_pcm_direct_semaphore_discard(dsnoop);
512 if (--fail_sem_loop <= 0)
519 first_instance = ret = snd_pcm_direct_shm_create_or_connect(dsnoop);
521 SNDERR("unable to create IPC shm instance");
525 pcm->ops = &snd_pcm_dsnoop_ops;
526 pcm->fast_ops = &snd_pcm_dsnoop_fast_ops;
527 pcm->private_data = dsnoop;
528 dsnoop->state = SND_PCM_STATE_OPEN;
530 if (first_instance) {
531 ret = snd_pcm_open_slave(&spcm, root, sconf, stream, mode);
533 SNDERR("unable to open slave");
537 if (snd_pcm_type(spcm) != SND_PCM_TYPE_HW) {
538 SNDERR("dsnoop plugin can be only connected to hw plugin");
542 ret = snd_pcm_direct_initialize_slave(dsnoop, spcm, params);
544 SNDERR("unable to initialize slave");
550 ret = snd_pcm_direct_server_create(dsnoop);
552 SNDERR("unable to create server");
556 dsnoop->shmptr->type = spcm->type;
558 ret = snd_pcm_direct_client_connect(dsnoop);
560 SNDERR("unable to connect client");
564 ret = snd_pcm_hw_open_fd(&spcm, "dsnoop_client", dsnoop->hw_fd, 0);
566 SNDERR("unable to open hardware");
570 spcm->donot_close = 1;
572 spcm->buffer_size = dsnoop->shmptr->s.buffer_size;
573 spcm->sample_bits = dsnoop->shmptr->s.sample_bits;
574 spcm->channels = dsnoop->shmptr->s.channels;
575 spcm->format = dsnoop->shmptr->s.format;
576 spcm->boundary = dsnoop->shmptr->s.boundary;
577 spcm->info = dsnoop->shmptr->s.info;
578 ret = snd_pcm_mmap(spcm);
580 SNDERR("unable to mmap channels");
586 ret = snd_pcm_direct_initialize_poll_fd(dsnoop);
588 SNDERR("unable to initialize poll_fd");
592 pcm->poll_fd = dsnoop->poll_fd;
593 pcm->poll_events = POLLIN; /* it's different than other plugins */
596 snd_pcm_set_hw_ptr(pcm, &dsnoop->hw_ptr, -1, 0);
597 snd_pcm_set_appl_ptr(pcm, &dsnoop->appl_ptr, -1, 0);
599 if (dsnoop->channels == UINT_MAX)
600 dsnoop->channels = dsnoop->shmptr->s.channels;
602 snd_pcm_direct_semaphore_up(dsnoop, DIRECT_IPC_SEM_CLIENT);
610 snd_timer_close(dsnoop->timer);
612 snd_pcm_direct_server_discard(dsnoop);
614 snd_pcm_direct_client_discard(dsnoop);
617 if (dsnoop->shmid >= 0) {
618 if (snd_pcm_direct_shm_discard(dsnoop) > 0) {
619 if (dsnoop->semid >= 0) {
620 if (snd_pcm_direct_semaphore_discard(dsnoop) < 0)
621 snd_pcm_direct_semaphore_up(dsnoop, DIRECT_IPC_SEM_CLIENT);
625 if (dsnoop->bindings)
626 free(dsnoop->bindings);
634 /*! \page pcm_plugins
636 \section pcm_plugins_snoop Plugin: dsnoop
638 This plugin splits one capture stream to more.
639 It works the reverse way of \ref pcm_plugins_dmix "dmix plugin",
640 reading the shared capture buffer from many clients concurrently.
641 The meaning of parameters below are almost identical with
646 type dsnoop # Direct snoop
647 ipc_key INT # unique IPC key
648 ipc_key_add_uid BOOL # add current uid to unique IPC key
651 slave { # Slave definition
652 pcm STR # slave PCM name
654 pcm { } # slave PCM definition
655 format STR # format definition
656 rate INT # rate definition
658 period_time INT # in usec
660 period_size INT # in bytes
661 buffer_time INT # in usec
663 buffer_size INT # in bytes
664 periods INT # when buffer_size or buffer_time is not specified
666 bindings { # note: this is client independent!!!
667 N INT # maps slave channel to client channel N
672 \subsection pcm_plugins_dsnoop_funcref Function reference
675 <LI>snd_pcm_dsnoop_open()
676 <LI>_snd_pcm_dsnoop_open()
682 * \brief Creates a new dsnoop PCM
683 * \param pcmp Returns created PCM handle
684 * \param name Name of PCM
685 * \param root Root configuration node
686 * \param conf Configuration node with dsnoop PCM description
687 * \param stream PCM Stream
688 * \param mode PCM Mode
689 * \warning Using of this function might be dangerous in the sense
690 * of compatibility reasons. The prototype might be freely
693 int _snd_pcm_dsnoop_open(snd_pcm_t **pcmp, const char *name,
694 snd_config_t *root, snd_config_t *conf,
695 snd_pcm_stream_t stream, int mode)
697 snd_config_iterator_t i, next;
698 snd_config_t *slave = NULL, *bindings = NULL, *sconf;
699 struct slave_params params;
700 int bsize, psize, ipc_key_add_uid = 0;
702 mode_t ipc_perm = 0600;
705 snd_config_for_each(i, next, conf) {
706 snd_config_t *n = snd_config_iterator_entry(i);
708 if (snd_config_get_id(n, &id) < 0)
710 if (snd_pcm_conf_generic_id(id))
712 if (strcmp(id, "ipc_key") == 0) {
714 err = snd_config_get_integer(n, &key);
716 SNDERR("The field ipc_key must be an integer type");
722 if (strcmp(id, "ipc_perm") == 0) {
725 err = snd_config_get_ascii(n, &perm);
727 SNDERR("The field ipc_perm must be a valid file permission");
730 if (isdigit(*perm) == 0) {
731 SNDERR("The field ipc_perm must be a valid file permission");
734 ipc_perm = strtol(perm, &endp, 8);
737 if (strcmp(id, "ipc_key_add_uid") == 0) {
739 err = snd_config_get_ascii(n, &tmp);
741 SNDERR("The field ipc_key_add_uid must be a boolean type");
744 err = snd_config_get_bool_ascii(tmp);
747 SNDERR("The field ipc_key_add_uid must be a boolean type");
750 ipc_key_add_uid = err;
753 if (strcmp(id, "slave") == 0) {
757 if (strcmp(id, "bindings") == 0) {
761 SNDERR("Unknown field %s", id);
765 SNDERR("slave is not defined");
771 SNDERR("Unique IPC key is not defined");
774 /* the default settings, it might be invalid for some hardware */
775 params.format = SND_PCM_FORMAT_S16;
778 params.period_time = 125000; /* 0.125 seconds */
779 params.buffer_time = -1;
782 err = snd_pcm_slave_conf(root, slave, &sconf, 8,
783 SND_PCM_HW_PARAM_FORMAT, 0, ¶ms.format,
784 SND_PCM_HW_PARAM_RATE, 0, ¶ms.rate,
785 SND_PCM_HW_PARAM_CHANNELS, 0, ¶ms.channels,
786 SND_PCM_HW_PARAM_PERIOD_TIME, 0, ¶ms.period_time,
787 SND_PCM_HW_PARAM_BUFFER_TIME, 0, ¶ms.buffer_time,
788 SND_PCM_HW_PARAM_PERIOD_SIZE, 0, &psize,
789 SND_PCM_HW_PARAM_BUFFER_SIZE, 0, &bsize,
790 SND_PCM_HW_PARAM_PERIODS, 0, ¶ms.periods);
794 /* sorry, limited features */
795 if (params.format != SND_PCM_FORMAT_S16 &&
796 params.format != SND_PCM_FORMAT_S32) {
797 SNDERR("invalid format, specify s16 or s32");
798 snd_config_delete(sconf);
802 params.period_size = psize;
803 params.buffer_size = bsize;
804 err = snd_pcm_dsnoop_open(pcmp, name, ipc_key, ipc_perm, ¶ms, bindings, root, sconf, stream, mode);
806 snd_config_delete(sconf);
810 SND_DLSYM_BUILD_VERSION(_snd_pcm_dsnoop_open, SND_PCM_DLSYM_VERSION);