summaryrefslogtreecommitdiff
path: root/sys/sunaudio/gstsunaudiosink.c
blob: 2a3cf19284906b92eccd72417a58ee3ec6d5af33 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
/*
 * GStreamer - SunAudio sink
 * Copyright (C) 2004 David A. Schleef <ds@schleef.org>
 * Copyright (C) 2005,2006 Sun Microsystems, Inc.,
 *               Brian Cameron <brian.cameron@sun.com>
 * Copyright (C) 2006 Jan Schmidt <thaytan@mad.scientist.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:element-sunaudiosink
 *
 * sunaudiosink is an audio sink designed to work with the Sun Audio
 * interface available in Solaris.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch audiotestsrc volume=0.5 ! sunaudiosink
 * ]|
 * </refsect2>
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <fcntl.h>
#include <string.h>
#include <stropts.h>
#include <unistd.h>
#include <sys/mman.h>

#include "gstsunaudiosink.h"

GST_DEBUG_CATEGORY_EXTERN (sunaudio_debug);
#define GST_CAT_DEFAULT sunaudio_debug

static void gst_sunaudiosink_base_init (gpointer g_class);
static void gst_sunaudiosink_class_init (GstSunAudioSinkClass * klass);
static void gst_sunaudiosink_init (GstSunAudioSink * filter);
static void gst_sunaudiosink_dispose (GObject * object);
static void gst_sunaudiosink_finalize (GObject * object);

static void gst_sunaudiosink_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static void gst_sunaudiosink_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static GstCaps *gst_sunaudiosink_getcaps (GstBaseSink * bsink);

static gboolean gst_sunaudiosink_open (GstAudioSink * asink);
static gboolean gst_sunaudiosink_close (GstAudioSink * asink);
static gboolean gst_sunaudiosink_prepare (GstAudioSink * asink,
    GstRingBufferSpec * spec);
static gboolean gst_sunaudiosink_unprepare (GstAudioSink * asink);
static guint gst_sunaudiosink_write (GstAudioSink * asink, gpointer data,
    guint length);
static guint gst_sunaudiosink_delay (GstAudioSink * asink);
static void gst_sunaudiosink_reset (GstAudioSink * asink);

#define DEFAULT_DEVICE  "/dev/audio"
enum
{
  PROP_0,
  PROP_DEVICE,
};

static GstStaticPadTemplate gst_sunaudiosink_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("audio/x-raw-int, "
        "endianness = (int) BYTE_ORDER, "
        "signed = (boolean) TRUE, " "width = (int) 16, " "depth = (int) 16, "
        /* [5510,48000] seems to be a Solaris limit */
        "rate = (int) [ 5510, 48000 ], " "channels = (int) [ 1, 2 ]")
    );

static GstElementClass *parent_class = NULL;

GType
gst_sunaudiosink_get_type (void)
{
  static GType plugin_type = 0;

  if (!plugin_type) {
    static const GTypeInfo plugin_info = {
      sizeof (GstSunAudioSinkClass),
      gst_sunaudiosink_base_init,
      NULL,
      (GClassInitFunc) gst_sunaudiosink_class_init,
      NULL,
      NULL,
      sizeof (GstSunAudioSink),
      0,
      (GInstanceInitFunc) gst_sunaudiosink_init,
    };

    plugin_type = g_type_register_static (GST_TYPE_AUDIO_SINK,
        "GstSunAudioSink", &plugin_info, 0);
  }
  return plugin_type;
}

static void
gst_sunaudiosink_dispose (GObject * object)
{
  G_OBJECT_CLASS (parent_class)->dispose (object);
}

static void
gst_sunaudiosink_finalize (GObject * object)
{
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (object);

  g_mutex_free (sunaudiosink->write_mutex);
  g_cond_free (sunaudiosink->sleep_cond);

  g_free (sunaudiosink->device);

  if (sunaudiosink->fd != -1) {
    close (sunaudiosink->fd);
    sunaudiosink->fd = -1;
  }

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gst_sunaudiosink_base_init (gpointer g_class)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_add_static_pad_template (element_class,
      &gst_sunaudiosink_factory);
  gst_element_class_set_details_simple (element_class, "Sun Audio Sink",
      "Sink/Audio",
      "Audio sink for Sun Audio devices",
      "David A. Schleef <ds@schleef.org>, "
      "Brian Cameron <brian.cameron@sun.com>");
}

static void
gst_sunaudiosink_class_init (GstSunAudioSinkClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;
  GstBaseSinkClass *gstbasesink_class;
  GstBaseAudioSinkClass *gstbaseaudiosink_class;
  GstAudioSinkClass *gstaudiosink_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;
  gstbasesink_class = (GstBaseSinkClass *) klass;
  gstbaseaudiosink_class = (GstBaseAudioSinkClass *) klass;
  gstaudiosink_class = (GstAudioSinkClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->dispose = gst_sunaudiosink_dispose;
  gobject_class->finalize = gst_sunaudiosink_finalize;

  gobject_class->set_property = gst_sunaudiosink_set_property;
  gobject_class->get_property = gst_sunaudiosink_get_property;

  gstbasesink_class->get_caps = GST_DEBUG_FUNCPTR (gst_sunaudiosink_getcaps);

  gstaudiosink_class->open = GST_DEBUG_FUNCPTR (gst_sunaudiosink_open);
  gstaudiosink_class->close = GST_DEBUG_FUNCPTR (gst_sunaudiosink_close);
  gstaudiosink_class->prepare = GST_DEBUG_FUNCPTR (gst_sunaudiosink_prepare);
  gstaudiosink_class->unprepare =
      GST_DEBUG_FUNCPTR (gst_sunaudiosink_unprepare);
  gstaudiosink_class->write = GST_DEBUG_FUNCPTR (gst_sunaudiosink_write);
  gstaudiosink_class->delay = GST_DEBUG_FUNCPTR (gst_sunaudiosink_delay);
  gstaudiosink_class->reset = GST_DEBUG_FUNCPTR (gst_sunaudiosink_reset);

  g_object_class_install_property (gobject_class, PROP_DEVICE,
      g_param_spec_string ("device", "Device", "Audio Device (/dev/audio)",
          DEFAULT_DEVICE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}

static void
gst_sunaudiosink_init (GstSunAudioSink * sunaudiosink)
{
  const char *audiodev;

  GST_DEBUG_OBJECT (sunaudiosink, "initializing sunaudiosink");

  sunaudiosink->fd = -1;

  audiodev = g_getenv ("AUDIODEV");
  if (audiodev == NULL)
    audiodev = DEFAULT_DEVICE;
  sunaudiosink->device = g_strdup (audiodev);

  /* mutex and gcond used to control the write method */
  sunaudiosink->write_mutex = g_mutex_new ();
  sunaudiosink->sleep_cond = g_cond_new ();
}

static void
gst_sunaudiosink_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstSunAudioSink *sunaudiosink;

  sunaudiosink = GST_SUNAUDIO_SINK (object);

  switch (prop_id) {
    case PROP_DEVICE:
      GST_OBJECT_LOCK (sunaudiosink);
      g_free (sunaudiosink->device);
      sunaudiosink->device = g_strdup (g_value_get_string (value));
      GST_OBJECT_UNLOCK (sunaudiosink);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_sunaudiosink_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstSunAudioSink *sunaudiosink;

  sunaudiosink = GST_SUNAUDIO_SINK (object);

  switch (prop_id) {
    case PROP_DEVICE:
      GST_OBJECT_LOCK (sunaudiosink);
      g_value_set_string (value, sunaudiosink->device);
      GST_OBJECT_UNLOCK (sunaudiosink);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static GstCaps *
gst_sunaudiosink_getcaps (GstBaseSink * bsink)
{
  GstPadTemplate *pad_template;
  GstCaps *caps = NULL;
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (bsink);

  GST_DEBUG_OBJECT (sunaudiosink, "getcaps called");

  pad_template = gst_static_pad_template_get (&gst_sunaudiosink_factory);
  caps = gst_caps_copy (gst_pad_template_get_caps (pad_template));

  gst_object_unref (pad_template);

  return caps;
}

static gboolean
gst_sunaudiosink_open (GstAudioSink * asink)
{
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (asink);
  int fd, ret;

  /* First try to open non-blocking */
  GST_OBJECT_LOCK (sunaudiosink);
  fd = open (sunaudiosink->device, O_WRONLY | O_NONBLOCK);

  if (fd >= 0) {
    close (fd);
    fd = open (sunaudiosink->device, O_WRONLY);
  }

  if (fd == -1) {
    GST_OBJECT_UNLOCK (sunaudiosink);
    goto open_failed;
  }

  sunaudiosink->fd = fd;
  GST_OBJECT_UNLOCK (sunaudiosink);

  ret = ioctl (fd, AUDIO_GETDEV, &sunaudiosink->dev);
  if (ret == -1)
    goto ioctl_error;

  GST_DEBUG_OBJECT (sunaudiosink, "name %s", sunaudiosink->dev.name);
  GST_DEBUG_OBJECT (sunaudiosink, "version %s", sunaudiosink->dev.version);
  GST_DEBUG_OBJECT (sunaudiosink, "config %s", sunaudiosink->dev.config);

  ret = ioctl (fd, AUDIO_GETINFO, &sunaudiosink->info);
  if (ret == -1)
    goto ioctl_error;

  GST_DEBUG_OBJECT (sunaudiosink, "monitor_gain %d",
      sunaudiosink->info.monitor_gain);
  GST_DEBUG_OBJECT (sunaudiosink, "output_muted %d",
      sunaudiosink->info.output_muted);
  GST_DEBUG_OBJECT (sunaudiosink, "hw_features %08x",
      sunaudiosink->info.hw_features);
  GST_DEBUG_OBJECT (sunaudiosink, "sw_features %08x",
      sunaudiosink->info.sw_features);
  GST_DEBUG_OBJECT (sunaudiosink, "sw_features_enabled %08x",
      sunaudiosink->info.sw_features_enabled);

  return TRUE;

open_failed:
  GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, OPEN_WRITE, (NULL),
      ("can't open connection to Sun Audio device %s", sunaudiosink->device));
  return FALSE;
ioctl_error:
  close (sunaudiosink->fd);
  GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
          strerror (errno)));
  return FALSE;
}

static gboolean
gst_sunaudiosink_close (GstAudioSink * asink)
{
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (asink);

  if (sunaudiosink->fd != -1) {
    close (sunaudiosink->fd);
    sunaudiosink->fd = -1;
  }
  return TRUE;
}

static gboolean
gst_sunaudiosink_prepare (GstAudioSink * asink, GstRingBufferSpec * spec)
{
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (asink);
  audio_info_t ainfo;
  int ret;
  int ports;

  ret = ioctl (sunaudiosink->fd, AUDIO_GETINFO, &ainfo);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
    return FALSE;
  }

  if (spec->width != 16)
    return FALSE;

  ports = ainfo.play.port;

  AUDIO_INITINFO (&ainfo);

  ainfo.play.sample_rate = spec->rate;
  ainfo.play.channels = spec->channels;
  ainfo.play.precision = spec->width;
  ainfo.play.encoding = AUDIO_ENCODING_LINEAR;
  ainfo.play.port = ports;

  /* buffer_time for playback is not implemented in Solaris at the moment,
     but at some point in the future, it might be */
  ainfo.play.buffer_size =
      gst_util_uint64_scale (spec->rate * spec->bytes_per_sample,
      spec->buffer_time, GST_SECOND / GST_USECOND);

  spec->silence_sample[0] = 0;
  spec->silence_sample[1] = 0;
  spec->silence_sample[2] = 0;
  spec->silence_sample[3] = 0;

  ret = ioctl (sunaudiosink->fd, AUDIO_SETINFO, &ainfo);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
    return FALSE;
  }

  /* Now read back the info to find out the actual buffer size and set 
     segtotal */
  AUDIO_INITINFO (&ainfo);

  ret = ioctl (sunaudiosink->fd, AUDIO_GETINFO, &ainfo);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
    return FALSE;
  }
#if 0
  /* We don't actually use the buffer_size from the sound device, because
   * it seems it's just bogus sometimes */
  sunaudiosink->segtotal = spec->segtotal =
      ainfo.play.buffer_size / spec->segsize;
#else
  sunaudiosink->segtotal = spec->segtotal;
#endif
  sunaudiosink->segtotal_samples =
      spec->segtotal * spec->segsize / spec->bytes_per_sample;

  sunaudiosink->segs_written = (gint) ainfo.play.eof;
  sunaudiosink->samples_written = ainfo.play.samples;
  sunaudiosink->bytes_per_sample = spec->bytes_per_sample;

  GST_DEBUG_OBJECT (sunaudiosink, "Got device buffer_size of %u",
      ainfo.play.buffer_size);

  return TRUE;
}

static gboolean
gst_sunaudiosink_unprepare (GstAudioSink * asink)
{
  return TRUE;
}

#define LOOP_WHILE_EINTR(v,func) do { (v) = (func); } \
		while ((v) == -1 && errno == EINTR);

/* Called with the write_mutex held */
static void
gst_sunaudio_sink_do_delay (GstSunAudioSink * sink)
{
  GstBaseAudioSink *ba_sink = GST_BASE_AUDIO_SINK (sink);
  GstClockTime total_sleep;
  GstClockTime max_sleep;
  gint sleep_usecs;
  GTimeVal sleep_end;
  gint err;
  audio_info_t ainfo;
  guint diff;

  /* This code below ensures that we don't race any further than buffer_time 
   * ahead of the audio output, by sleeping if the next write call would cause
   * us to advance too far in the ring-buffer */
  LOOP_WHILE_EINTR (err, ioctl (sink->fd, AUDIO_GETINFO, &ainfo));
  if (err < 0)
    goto write_error;

  /* Compute our offset from the output (copes with overflow) */
  diff = (guint) (sink->segs_written) - ainfo.play.eof;
  if (diff > sink->segtotal) {
    /* This implies that reset did a flush just as the sound device aquired
     * some buffers internally, and it causes us to be out of sync with the
     * eof measure. This corrects it */
    sink->segs_written = ainfo.play.eof;
    diff = 0;
  }

  if (diff + 1 < sink->segtotal)
    return;                     /* no need to sleep at all */

  /* Never sleep longer than the initial number of undrained segments in the 
     device plus one */
  total_sleep = 0;
  max_sleep = (diff + 1) * (ba_sink->latency_time * GST_USECOND);
  /* sleep for a segment period between .eof polls */
  sleep_usecs = ba_sink->latency_time;

  /* Current time is our reference point */
  g_get_current_time (&sleep_end);

  /* If the next segment would take us too far along the ring buffer,
   * sleep for a bit to free up a slot. If there were a way to find out
   * when the eof field actually increments, we could use, but the only
   * notification mechanism seems to be SIGPOLL, which we can't use from
   * a support library */
  while (diff + 1 >= sink->segtotal && total_sleep < max_sleep) {
    GST_LOG_OBJECT (sink, "need to block to drain segment(s). "
        "Sleeping for %d us", sleep_usecs);

    g_time_val_add (&sleep_end, sleep_usecs);

    if (g_cond_timed_wait (sink->sleep_cond, sink->write_mutex, &sleep_end)) {
      GST_LOG_OBJECT (sink, "Waking up early due to reset");
      return;                   /* Got told to wake up */
    }
    total_sleep += (sleep_usecs * GST_USECOND);

    LOOP_WHILE_EINTR (err, ioctl (sink->fd, AUDIO_GETINFO, &ainfo));
    if (err < 0)
      goto write_error;

    /* Compute our (new) offset from the output (copes with overflow) */
    diff = (guint) g_atomic_int_get (&sink->segs_written) - ainfo.play.eof;
  }

  return;

write_error:
  GST_ELEMENT_ERROR (sink, RESOURCE, OPEN_WRITE, (NULL),
      ("Playback error on device '%s': %s", sink->device, strerror (errno)));
  return;
}

static guint
gst_sunaudiosink_write (GstAudioSink * asink, gpointer data, guint length)
{
  GstSunAudioSink *sink = GST_SUNAUDIO_SINK (asink);

  gint bytes_written, err;

  g_mutex_lock (sink->write_mutex);
  if (sink->flushing) {
    /* Exit immediately if reset tells us to */
    g_mutex_unlock (sink->write_mutex);
    return length;
  }

  LOOP_WHILE_EINTR (bytes_written, write (sink->fd, data, length));
  if (bytes_written < 0) {
    err = bytes_written;
    goto write_error;
  }

  /* Increment our sample counter, for delay calcs */
  g_atomic_int_add (&sink->samples_written, length / sink->bytes_per_sample);

  /* Don't consider the segment written if we didn't output the whole lot yet */
  if (bytes_written < length) {
    g_mutex_unlock (sink->write_mutex);
    return (guint) bytes_written;
  }

  /* Write a zero length output to trigger increment of the eof field */
  LOOP_WHILE_EINTR (err, write (sink->fd, NULL, 0));
  if (err < 0)
    goto write_error;

  /* Count this extra segment we've written */
  sink->segs_written += 1;

  /* Now delay so we don't overrun the ring buffer */
  gst_sunaudio_sink_do_delay (sink);

  g_mutex_unlock (sink->write_mutex);
  return length;

write_error:
  g_mutex_unlock (sink->write_mutex);

  GST_ELEMENT_ERROR (sink, RESOURCE, OPEN_WRITE, (NULL),
      ("Playback error on device '%s': %s", sink->device, strerror (errno)));
  return length;                /* Say we wrote the segment to let the ringbuffer exit */
}

/*
 * Provide the current number of unplayed samples that have been written
 * to the device */
static guint
gst_sunaudiosink_delay (GstAudioSink * asink)
{
  GstSunAudioSink *sink = GST_SUNAUDIO_SINK (asink);
  audio_info_t ainfo;
  gint ret;
  guint offset;

  ret = ioctl (sink->fd, AUDIO_GETINFO, &ainfo);
  if (G_UNLIKELY (ret == -1))
    return 0;

  offset = (g_atomic_int_get (&sink->samples_written) - ainfo.play.samples);

  /* If the offset is larger than the total ringbuffer size, then we asked
     between the write call and when samples_written is updated */
  if (G_UNLIKELY (offset > sink->segtotal_samples))
    return 0;

  return offset;
}

static void
gst_sunaudiosink_reset (GstAudioSink * asink)
{
  /* Get current values */
  GstSunAudioSink *sunaudiosink = GST_SUNAUDIO_SINK (asink);
  audio_info_t ainfo;
  int ret;

  ret = ioctl (sunaudiosink->fd, AUDIO_GETINFO, &ainfo);
  if (ret == -1) {
    /*
     * Should never happen, but if we couldn't getinfo, then no point
     * trying to setinfo
     */
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
    return;
  }

  /*
   * Pause the audio - so audio stops playing immediately rather than
   * waiting for the ringbuffer to empty.
   */
  ainfo.play.pause = !NULL;
  ret = ioctl (sunaudiosink->fd, AUDIO_SETINFO, &ainfo);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
  }

  /* Flush the audio */
  ret = ioctl (sunaudiosink->fd, I_FLUSH, FLUSHW);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
  }

  /* Now, we take the write_mutex and signal to ensure the write thread
   * is not busy, and we signal the condition to wake up any sleeper,
   * then we flush again in case the write wrote something after we flushed,
   * and finally release the lock and unpause */
  g_mutex_lock (sunaudiosink->write_mutex);
  sunaudiosink->flushing = TRUE;

  g_cond_signal (sunaudiosink->sleep_cond);

  ret = ioctl (sunaudiosink->fd, I_FLUSH, FLUSHW);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
  }

  /* unpause the audio */
  ainfo.play.pause = NULL;
  ret = ioctl (sunaudiosink->fd, AUDIO_SETINFO, &ainfo);
  if (ret == -1) {
    GST_ELEMENT_ERROR (sunaudiosink, RESOURCE, SETTINGS, (NULL), ("%s",
            strerror (errno)));
  }

  /* After flushing the audio device, we need to remeasure the sample count
   * and segments written count so we're in sync with the device */

  sunaudiosink->segs_written = ainfo.play.eof;
  g_atomic_int_set (&sunaudiosink->samples_written, ainfo.play.samples);

  sunaudiosink->flushing = FALSE;
  g_mutex_unlock (sunaudiosink->write_mutex);
}