2 * QEMU ALSA audio driver
4 * Copyright (c) 2005 Vassili Karpov (malc)
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include <alsa/asoundlib.h>
25 #include "qemu-common.h"
26 #include "qemu-char.h"
29 #if QEMU_GNUC_PREREQ(4, 3)
30 #pragma GCC diagnostic ignored "-Waddress"
33 #define AUDIO_CAP "alsa"
34 #include "audio_int.h"
43 typedef struct ALSAVoiceOut {
49 struct pollhlp pollhlp;
52 typedef struct ALSAVoiceIn {
56 struct pollhlp pollhlp;
62 const char *pcm_name_in;
63 const char *pcm_name_out;
64 unsigned int buffer_size_in;
65 unsigned int period_size_in;
66 unsigned int buffer_size_out;
67 unsigned int period_size_out;
68 unsigned int threshold;
70 int buffer_size_in_overridden;
71 int period_size_in_overridden;
73 int buffer_size_out_overridden;
74 int period_size_out_overridden;
77 .buffer_size_out = 4096,
78 .period_size_out = 1024,
79 .pcm_name_out = "default",
80 .pcm_name_in = "default",
83 struct alsa_params_req {
89 unsigned int buffer_size;
90 unsigned int period_size;
93 struct alsa_params_obt {
98 snd_pcm_uframes_t samples;
101 static void GCC_FMT_ATTR (2, 3) alsa_logerr (int err, const char *fmt, ...)
106 AUD_vlog (AUDIO_CAP, fmt, ap);
109 AUD_log (AUDIO_CAP, "Reason: %s\n", snd_strerror (err));
112 static void GCC_FMT_ATTR (3, 4) alsa_logerr2 (
121 AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);
124 AUD_vlog (AUDIO_CAP, fmt, ap);
127 AUD_log (AUDIO_CAP, "Reason: %s\n", snd_strerror (err));
130 static void alsa_fini_poll (struct pollhlp *hlp)
133 struct pollfd *pfds = hlp->pfds;
136 for (i = 0; i < hlp->count; ++i) {
137 qemu_set_fd_handler (pfds[i].fd, NULL, NULL, NULL);
146 static void alsa_anal_close1 (snd_pcm_t **handlep)
148 int err = snd_pcm_close (*handlep);
150 alsa_logerr (err, "Failed to close PCM handle %p\n", *handlep);
155 static void alsa_anal_close (snd_pcm_t **handlep, struct pollhlp *hlp)
157 alsa_fini_poll (hlp);
158 alsa_anal_close1 (handlep);
161 static int alsa_recover (snd_pcm_t *handle)
163 int err = snd_pcm_prepare (handle);
165 alsa_logerr (err, "Failed to prepare handle %p\n", handle);
171 static int alsa_resume (snd_pcm_t *handle)
173 int err = snd_pcm_resume (handle);
175 alsa_logerr (err, "Failed to resume handle %p\n", handle);
181 static void alsa_poll_handler (void *opaque)
184 snd_pcm_state_t state;
185 struct pollhlp *hlp = opaque;
186 unsigned short revents;
188 count = poll (hlp->pfds, hlp->count, 0);
190 dolog ("alsa_poll_handler: poll %s\n", strerror (errno));
198 /* XXX: ALSA example uses initial count, not the one returned by
200 err = snd_pcm_poll_descriptors_revents (hlp->handle, hlp->pfds,
201 hlp->count, &revents);
203 alsa_logerr (err, "snd_pcm_poll_descriptors_revents");
207 if (!(revents & hlp->mask)) {
209 dolog ("revents = %d\n", revents);
214 state = snd_pcm_state (hlp->handle);
216 case SND_PCM_STATE_SETUP:
217 alsa_recover (hlp->handle);
220 case SND_PCM_STATE_XRUN:
221 alsa_recover (hlp->handle);
224 case SND_PCM_STATE_SUSPENDED:
225 alsa_resume (hlp->handle);
228 case SND_PCM_STATE_PREPARED:
229 audio_run ("alsa run (prepared)");
232 case SND_PCM_STATE_RUNNING:
233 audio_run ("alsa run (running)");
237 dolog ("Unexpected state %d\n", state);
241 static int alsa_poll_helper (snd_pcm_t *handle, struct pollhlp *hlp, int mask)
246 count = snd_pcm_poll_descriptors_count (handle);
248 dolog ("Could not initialize poll mode\n"
249 "Invalid number of poll descriptors %d\n", count);
253 pfds = audio_calloc ("alsa_poll_helper", count, sizeof (*pfds));
255 dolog ("Could not initialize poll mode\n");
259 err = snd_pcm_poll_descriptors (handle, pfds, count);
261 alsa_logerr (err, "Could not initialize poll mode\n"
262 "Could not obtain poll descriptors\n");
267 for (i = 0; i < count; ++i) {
268 if (pfds[i].events & POLLIN) {
269 err = qemu_set_fd_handler (pfds[i].fd, alsa_poll_handler,
272 if (pfds[i].events & POLLOUT) {
274 dolog ("POLLOUT %d %d\n", i, pfds[i].fd);
276 err = qemu_set_fd_handler (pfds[i].fd, NULL,
277 alsa_poll_handler, hlp);
280 dolog ("Set handler events=%#x index=%d fd=%d err=%d\n",
281 pfds[i].events, i, pfds[i].fd, err);
285 dolog ("Failed to set handler events=%#x index=%d fd=%d err=%d\n",
286 pfds[i].events, i, pfds[i].fd, err);
289 qemu_set_fd_handler (pfds[i].fd, NULL, NULL, NULL);
297 hlp->handle = handle;
302 static int alsa_poll_out (HWVoiceOut *hw)
304 ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
306 return alsa_poll_helper (alsa->handle, &alsa->pollhlp, POLLOUT);
309 static int alsa_poll_in (HWVoiceIn *hw)
311 ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
313 return alsa_poll_helper (alsa->handle, &alsa->pollhlp, POLLIN);
316 static int alsa_write (SWVoiceOut *sw, void *buf, int len)
318 return audio_pcm_sw_write (sw, buf, len);
321 static snd_pcm_format_t aud_to_alsafmt (audfmt_e fmt)
325 return SND_PCM_FORMAT_S8;
328 return SND_PCM_FORMAT_U8;
331 return SND_PCM_FORMAT_S16_LE;
334 return SND_PCM_FORMAT_U16_LE;
337 return SND_PCM_FORMAT_S32_LE;
340 return SND_PCM_FORMAT_U32_LE;
343 dolog ("Internal logic error: Bad audio format %d\n", fmt);
347 return SND_PCM_FORMAT_U8;
351 static int alsa_to_audfmt (snd_pcm_format_t alsafmt, audfmt_e *fmt,
355 case SND_PCM_FORMAT_S8:
360 case SND_PCM_FORMAT_U8:
365 case SND_PCM_FORMAT_S16_LE:
370 case SND_PCM_FORMAT_U16_LE:
375 case SND_PCM_FORMAT_S16_BE:
380 case SND_PCM_FORMAT_U16_BE:
385 case SND_PCM_FORMAT_S32_LE:
390 case SND_PCM_FORMAT_U32_LE:
395 case SND_PCM_FORMAT_S32_BE:
400 case SND_PCM_FORMAT_U32_BE:
406 dolog ("Unrecognized audio format %d\n", alsafmt);
413 static void alsa_dump_info (struct alsa_params_req *req,
414 struct alsa_params_obt *obt)
416 dolog ("parameter | requested value | obtained value\n");
417 dolog ("format | %10d | %10d\n", req->fmt, obt->fmt);
418 dolog ("channels | %10d | %10d\n",
419 req->nchannels, obt->nchannels);
420 dolog ("frequency | %10d | %10d\n", req->freq, obt->freq);
421 dolog ("============================================\n");
422 dolog ("requested: buffer size %d period size %d\n",
423 req->buffer_size, req->period_size);
424 dolog ("obtained: samples %ld\n", obt->samples);
427 static void alsa_set_threshold (snd_pcm_t *handle, snd_pcm_uframes_t threshold)
430 snd_pcm_sw_params_t *sw_params;
432 snd_pcm_sw_params_alloca (&sw_params);
434 err = snd_pcm_sw_params_current (handle, sw_params);
436 dolog ("Could not fully initialize DAC\n");
437 alsa_logerr (err, "Failed to get current software parameters\n");
441 err = snd_pcm_sw_params_set_start_threshold (handle, sw_params, threshold);
443 dolog ("Could not fully initialize DAC\n");
444 alsa_logerr (err, "Failed to set software threshold to %ld\n",
449 err = snd_pcm_sw_params (handle, sw_params);
451 dolog ("Could not fully initialize DAC\n");
452 alsa_logerr (err, "Failed to set software parameters\n");
457 static int alsa_open (int in, struct alsa_params_req *req,
458 struct alsa_params_obt *obt, snd_pcm_t **handlep)
461 snd_pcm_hw_params_t *hw_params;
464 unsigned int freq, nchannels;
465 const char *pcm_name = in ? conf.pcm_name_in : conf.pcm_name_out;
466 snd_pcm_uframes_t obt_buffer_size;
467 const char *typ = in ? "ADC" : "DAC";
468 snd_pcm_format_t obtfmt;
471 nchannels = req->nchannels;
472 size_in_usec = req->size_in_usec;
474 snd_pcm_hw_params_alloca (&hw_params);
479 in ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK,
483 alsa_logerr2 (err, typ, "Failed to open `%s':\n", pcm_name);
487 err = snd_pcm_hw_params_any (handle, hw_params);
489 alsa_logerr2 (err, typ, "Failed to initialize hardware parameters\n");
493 err = snd_pcm_hw_params_set_access (
496 SND_PCM_ACCESS_RW_INTERLEAVED
499 alsa_logerr2 (err, typ, "Failed to set access type\n");
503 err = snd_pcm_hw_params_set_format (handle, hw_params, req->fmt);
504 if (err < 0 && conf.verbose) {
505 alsa_logerr2 (err, typ, "Failed to set format %d\n", req->fmt);
508 err = snd_pcm_hw_params_set_rate_near (handle, hw_params, &freq, 0);
510 alsa_logerr2 (err, typ, "Failed to set frequency %d\n", req->freq);
514 err = snd_pcm_hw_params_set_channels_near (
520 alsa_logerr2 (err, typ, "Failed to set number of channels %d\n",
525 if (nchannels != 1 && nchannels != 2) {
526 alsa_logerr2 (err, typ,
527 "Can not handle obtained number of channels %d\n",
532 if (req->buffer_size) {
537 unsigned int btime = req->buffer_size;
539 err = snd_pcm_hw_params_set_buffer_time_near (
548 snd_pcm_uframes_t bsize = req->buffer_size;
550 err = snd_pcm_hw_params_set_buffer_size_near (
558 alsa_logerr2 (err, typ, "Failed to set buffer %s to %d\n",
559 size_in_usec ? "time" : "size", req->buffer_size);
563 if ((req->override_mask & 2) && (obt - req->buffer_size))
564 dolog ("Requested buffer %s %u was rejected, using %lu\n",
565 size_in_usec ? "time" : "size", req->buffer_size, obt);
568 if (req->period_size) {
573 unsigned int ptime = req->period_size;
575 err = snd_pcm_hw_params_set_period_time_near (
585 snd_pcm_uframes_t psize = req->period_size;
587 err = snd_pcm_hw_params_set_period_size_near (
597 alsa_logerr2 (err, typ, "Failed to set period %s to %d\n",
598 size_in_usec ? "time" : "size", req->period_size);
602 if (((req->override_mask & 1) && (obt - req->period_size)))
603 dolog ("Requested period %s %u was rejected, using %lu\n",
604 size_in_usec ? "time" : "size", req->period_size, obt);
607 err = snd_pcm_hw_params (handle, hw_params);
609 alsa_logerr2 (err, typ, "Failed to apply audio parameters\n");
613 err = snd_pcm_hw_params_get_buffer_size (hw_params, &obt_buffer_size);
615 alsa_logerr2 (err, typ, "Failed to get buffer size\n");
619 err = snd_pcm_hw_params_get_format (hw_params, &obtfmt);
621 alsa_logerr2 (err, typ, "Failed to get format\n");
625 if (alsa_to_audfmt (obtfmt, &obt->fmt, &obt->endianness)) {
626 dolog ("Invalid format was returned %d\n", obtfmt);
630 err = snd_pcm_prepare (handle);
632 alsa_logerr2 (err, typ, "Could not prepare handle %p\n", handle);
636 if (!in && conf.threshold) {
637 snd_pcm_uframes_t threshold;
640 bytes_per_sec = freq << (nchannels == 2);
658 threshold = (conf.threshold * bytes_per_sec) / 1000;
659 alsa_set_threshold (handle, threshold);
662 obt->nchannels = nchannels;
664 obt->samples = obt_buffer_size;
669 (obt->fmt != req->fmt ||
670 obt->nchannels != req->nchannels ||
671 obt->freq != req->freq)) {
672 dolog ("Audio parameters for %s\n", typ);
673 alsa_dump_info (req, obt);
677 alsa_dump_info (req, obt);
682 alsa_anal_close1 (&handle);
686 static snd_pcm_sframes_t alsa_get_avail (snd_pcm_t *handle)
688 snd_pcm_sframes_t avail;
690 avail = snd_pcm_avail_update (handle);
692 if (avail == -EPIPE) {
693 if (!alsa_recover (handle)) {
694 avail = snd_pcm_avail_update (handle);
700 "Could not obtain number of available frames\n");
708 static void alsa_write_pending (ALSAVoiceOut *alsa)
710 HWVoiceOut *hw = &alsa->hw;
712 while (alsa->pending) {
713 int left_till_end_samples = hw->samples - alsa->wpos;
714 int len = audio_MIN (alsa->pending, left_till_end_samples);
715 char *src = advance (alsa->pcm_buf, alsa->wpos << hw->info.shift);
718 snd_pcm_sframes_t written;
720 written = snd_pcm_writei (alsa->handle, src, len);
726 dolog ("Failed to write %d frames (wrote zero)\n", len);
731 if (alsa_recover (alsa->handle)) {
732 alsa_logerr (written, "Failed to write %d frames\n",
737 dolog ("Recovering from playback xrun\n");
742 /* stream is suspended and waiting for an
743 application recovery */
744 if (alsa_resume (alsa->handle)) {
745 alsa_logerr (written, "Failed to write %d frames\n",
750 dolog ("Resuming suspended output stream\n");
758 alsa_logerr (written, "Failed to write %d frames from %p\n",
764 alsa->wpos = (alsa->wpos + written) % hw->samples;
765 alsa->pending -= written;
771 static int alsa_run_out (HWVoiceOut *hw, int live)
773 ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
775 snd_pcm_sframes_t avail;
777 avail = alsa_get_avail (alsa->handle);
779 dolog ("Could not get number of available playback frames\n");
783 decr = audio_MIN (live, avail);
784 decr = audio_pcm_hw_clip_out (hw, alsa->pcm_buf, decr, alsa->pending);
785 alsa->pending += decr;
786 alsa_write_pending (alsa);
790 static void alsa_fini_out (HWVoiceOut *hw)
792 ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
794 ldebug ("alsa_fini\n");
795 alsa_anal_close (&alsa->handle, &alsa->pollhlp);
798 qemu_free (alsa->pcm_buf);
799 alsa->pcm_buf = NULL;
803 static int alsa_init_out (HWVoiceOut *hw, struct audsettings *as)
805 ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
806 struct alsa_params_req req;
807 struct alsa_params_obt obt;
809 struct audsettings obt_as;
811 req.fmt = aud_to_alsafmt (as->fmt);
813 req.nchannels = as->nchannels;
814 req.period_size = conf.period_size_out;
815 req.buffer_size = conf.buffer_size_out;
816 req.size_in_usec = conf.size_in_usec_out;
818 (conf.period_size_out_overridden ? 1 : 0) |
819 (conf.buffer_size_out_overridden ? 2 : 0);
821 if (alsa_open (0, &req, &obt, &handle)) {
825 obt_as.freq = obt.freq;
826 obt_as.nchannels = obt.nchannels;
827 obt_as.fmt = obt.fmt;
828 obt_as.endianness = obt.endianness;
830 audio_pcm_init_info (&hw->info, &obt_as);
831 hw->samples = obt.samples;
833 alsa->pcm_buf = audio_calloc (AUDIO_FUNC, obt.samples, 1 << hw->info.shift);
834 if (!alsa->pcm_buf) {
835 dolog ("Could not allocate DAC buffer (%d samples, each %d bytes)\n",
836 hw->samples, 1 << hw->info.shift);
837 alsa_anal_close1 (&handle);
841 alsa->handle = handle;
845 static int alsa_voice_ctl (snd_pcm_t *handle, const char *typ, int pause)
850 err = snd_pcm_drop (handle);
852 alsa_logerr (err, "Could not stop %s\n", typ);
857 err = snd_pcm_prepare (handle);
859 alsa_logerr (err, "Could not prepare handle for %s\n", typ);
867 static int alsa_ctl_out (HWVoiceOut *hw, int cmd, ...)
869 ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
878 poll_mode = va_arg (ap, int);
881 ldebug ("enabling voice\n");
882 if (poll_mode && alsa_poll_out (hw)) {
885 hw->poll_mode = poll_mode;
886 return alsa_voice_ctl (alsa->handle, "playback", 0);
890 ldebug ("disabling voice\n");
891 return alsa_voice_ctl (alsa->handle, "playback", 1);
897 static int alsa_init_in (HWVoiceIn *hw, struct audsettings *as)
899 ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
900 struct alsa_params_req req;
901 struct alsa_params_obt obt;
903 struct audsettings obt_as;
905 req.fmt = aud_to_alsafmt (as->fmt);
907 req.nchannels = as->nchannels;
908 req.period_size = conf.period_size_in;
909 req.buffer_size = conf.buffer_size_in;
910 req.size_in_usec = conf.size_in_usec_in;
912 (conf.period_size_in_overridden ? 1 : 0) |
913 (conf.buffer_size_in_overridden ? 2 : 0);
915 if (alsa_open (1, &req, &obt, &handle)) {
919 obt_as.freq = obt.freq;
920 obt_as.nchannels = obt.nchannels;
921 obt_as.fmt = obt.fmt;
922 obt_as.endianness = obt.endianness;
924 audio_pcm_init_info (&hw->info, &obt_as);
925 hw->samples = obt.samples;
927 alsa->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
928 if (!alsa->pcm_buf) {
929 dolog ("Could not allocate ADC buffer (%d samples, each %d bytes)\n",
930 hw->samples, 1 << hw->info.shift);
931 alsa_anal_close1 (&handle);
935 alsa->handle = handle;
939 static void alsa_fini_in (HWVoiceIn *hw)
941 ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
943 alsa_anal_close (&alsa->handle, &alsa->pollhlp);
946 qemu_free (alsa->pcm_buf);
947 alsa->pcm_buf = NULL;
951 static int alsa_run_in (HWVoiceIn *hw)
953 ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
954 int hwshift = hw->info.shift;
956 int live = audio_pcm_hw_get_live_in (hw);
957 int dead = hw->samples - live;
963 { .add = hw->wpos, .len = 0 },
964 { .add = 0, .len = 0 }
966 snd_pcm_sframes_t avail;
967 snd_pcm_uframes_t read_samples = 0;
973 avail = alsa_get_avail (alsa->handle);
975 dolog ("Could not get number of captured frames\n");
980 snd_pcm_state_t state;
982 state = snd_pcm_state (alsa->handle);
984 case SND_PCM_STATE_PREPARED:
987 case SND_PCM_STATE_SUSPENDED:
988 /* stream is suspended and waiting for an application recovery */
989 if (alsa_resume (alsa->handle)) {
990 dolog ("Failed to resume suspended input stream\n");
994 dolog ("Resuming suspended input stream\n");
999 dolog ("No frames available and ALSA state is %d\n", state);
1005 decr = audio_MIN (dead, avail);
1010 if (hw->wpos + decr > hw->samples) {
1011 bufs[0].len = (hw->samples - hw->wpos);
1012 bufs[1].len = (decr - (hw->samples - hw->wpos));
1018 for (i = 0; i < 2; ++i) {
1020 struct st_sample *dst;
1021 snd_pcm_sframes_t nread;
1022 snd_pcm_uframes_t len;
1026 src = advance (alsa->pcm_buf, bufs[i].add << hwshift);
1027 dst = hw->conv_buf + bufs[i].add;
1030 nread = snd_pcm_readi (alsa->handle, src, len);
1036 dolog ("Failed to read %ld frames (read zero)\n", len);
1041 if (alsa_recover (alsa->handle)) {
1042 alsa_logerr (nread, "Failed to read %ld frames\n", len);
1046 dolog ("Recovering from capture xrun\n");
1056 "Failed to read %ld frames from %p\n",
1064 hw->conv (dst, src, nread, &nominal_volume);
1066 src = advance (src, nread << hwshift);
1069 read_samples += nread;
1075 hw->wpos = (hw->wpos + read_samples) % hw->samples;
1076 return read_samples;
1079 static int alsa_read (SWVoiceIn *sw, void *buf, int size)
1081 return audio_pcm_sw_read (sw, buf, size);
1084 static int alsa_ctl_in (HWVoiceIn *hw, int cmd, ...)
1086 ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
1095 poll_mode = va_arg (ap, int);
1098 ldebug ("enabling voice\n");
1099 if (poll_mode && alsa_poll_in (hw)) {
1102 hw->poll_mode = poll_mode;
1104 return alsa_voice_ctl (alsa->handle, "capture", 0);
1108 ldebug ("disabling voice\n");
1109 if (hw->poll_mode) {
1111 alsa_fini_poll (&alsa->pollhlp);
1113 return alsa_voice_ctl (alsa->handle, "capture", 1);
1119 static void *alsa_audio_init (void)
1124 static void alsa_audio_fini (void *opaque)
1129 static struct audio_option alsa_options[] = {
1131 .name = "DAC_SIZE_IN_USEC",
1132 .tag = AUD_OPT_BOOL,
1133 .valp = &conf.size_in_usec_out,
1134 .descr = "DAC period/buffer size in microseconds (otherwise in frames)"
1137 .name = "DAC_PERIOD_SIZE",
1139 .valp = &conf.period_size_out,
1140 .descr = "DAC period size (0 to go with system default)",
1141 .overriddenp = &conf.period_size_out_overridden
1144 .name = "DAC_BUFFER_SIZE",
1146 .valp = &conf.buffer_size_out,
1147 .descr = "DAC buffer size (0 to go with system default)",
1148 .overriddenp = &conf.buffer_size_out_overridden
1151 .name = "ADC_SIZE_IN_USEC",
1152 .tag = AUD_OPT_BOOL,
1153 .valp = &conf.size_in_usec_in,
1155 "ADC period/buffer size in microseconds (otherwise in frames)"
1158 .name = "ADC_PERIOD_SIZE",
1160 .valp = &conf.period_size_in,
1161 .descr = "ADC period size (0 to go with system default)",
1162 .overriddenp = &conf.period_size_in_overridden
1165 .name = "ADC_BUFFER_SIZE",
1167 .valp = &conf.buffer_size_in,
1168 .descr = "ADC buffer size (0 to go with system default)",
1169 .overriddenp = &conf.buffer_size_in_overridden
1172 .name = "THRESHOLD",
1174 .valp = &conf.threshold,
1175 .descr = "(undocumented)"
1180 .valp = &conf.pcm_name_out,
1181 .descr = "DAC device name (for instance dmix)"
1186 .valp = &conf.pcm_name_in,
1187 .descr = "ADC device name"
1191 .tag = AUD_OPT_BOOL,
1192 .valp = &conf.verbose,
1193 .descr = "Behave in a more verbose way"
1195 { /* End of list */ }
1198 static struct audio_pcm_ops alsa_pcm_ops = {
1199 .init_out = alsa_init_out,
1200 .fini_out = alsa_fini_out,
1201 .run_out = alsa_run_out,
1202 .write = alsa_write,
1203 .ctl_out = alsa_ctl_out,
1205 .init_in = alsa_init_in,
1206 .fini_in = alsa_fini_in,
1207 .run_in = alsa_run_in,
1209 .ctl_in = alsa_ctl_in,
1212 struct audio_driver alsa_audio_driver = {
1214 .descr = "ALSA http://www.alsa-project.org",
1215 .options = alsa_options,
1216 .init = alsa_audio_init,
1217 .fini = alsa_audio_fini,
1218 .pcm_ops = &alsa_pcm_ops,
1219 .can_be_default = 1,
1220 .max_voices_out = INT_MAX,
1221 .max_voices_in = INT_MAX,
1222 .voice_size_out = sizeof (ALSAVoiceOut),
1223 .voice_size_in = sizeof (ALSAVoiceIn)