gstevent.c 37 KB
Newer Older
1 2 3
/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wim.taymans@chello.be>
4
 *                    2005 Wim Taymans <wim@fluendo.com>
5
 *
6
 * gstevent.c: GstEvent subsystem
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
 *
 * 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.
 */
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
23

24 25
/**
 * SECTION:gstevent
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
26 27
 * @short_description: Structure describing events that are passed up and down
 *                     a pipeline
28 29
 * @see_also: #GstPad, #GstElement
 *
30 31
 * The event class provides factory methods to construct and functions query
 * (parse) events.
32
 *
33 34
 * Events are usually created with gst_event_new_*() which takes event-type
 * specific parameters as arguments.
35 36
 * To send an event application will usually use gst_element_send_event() and
 * elements will use gst_pad_send_event() or gst_pad_push_event().
37 38 39
 * The event should be unreffed with gst_event_unref() if it has not been sent.
 *
 * Events that have been received can be parsed with their respective 
40
 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
41
 *
Wim Taymans's avatar
Wim Taymans committed
42 43 44 45
 * Events are passed between elements in parallel to the data stream. Some events
 * are serialized with buffers, others are not. Some events only travel downstream,
 * others only upstream. Some events can travel both upstream and downstream. 
 * 
46 47 48
 * The events are used to signal special conditions in the datastream such as
 * EOS (end of stream) or the start of a new stream-segment.
 * Events are also used to flush the pipeline of any pending data.
Wim Taymans's avatar
Wim Taymans committed
49
 *
50 51 52 53
 * Most of the event API is used inside plugins. Applications usually only 
 * construct and use seek events. 
 * To do that gst_event_new_seek() is used to create a seek event. It takes
 * the needed parameters to specity seeking time and mode.
Wim Taymans's avatar
Wim Taymans committed
54 55 56 57 58 59 60 61 62 63
 * <example>
 * <title>performing a seek on a pipeline</title>
 *   <programlisting>
 *   GstEvent *event;
 *   gboolean result;
 *   ...
 *   // construct a seek event to play the media from second 2 to 5, flush
 *   // the pipeline to decrease latency.
 *   event = gst_event_new_seek (1.0, 
 *      GST_FORMAT_TIME, 
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
64 65 66
 *      GST_SEEK_FLAG_FLUSH,
 *      GST_SEEK_TYPE_SET, 2 * GST_SECOND,
 *      GST_SEEK_TYPE_SET, 5 * GST_SECOND);
Wim Taymans's avatar
Wim Taymans committed
67 68 69 70 71 72 73
 *   ...
 *   result = gst_element_send_event (pipeline, event);
 *   if (!result)
 *     g_warning ("seek failed");
 *   ...
 *   </programlisting>
 * </example>
Wim Taymans's avatar
Wim Taymans committed
74
 *
75
 * Last reviewed on 2006-09-6 (0.10.10)
76
 */
Wim Taymans's avatar
Wim Taymans committed
77

78

79
#include "gst_private.h"
80
#include <string.h>             /* memcpy */
81 82

#include "gstinfo.h"
83
#include "gstevent.h"
Wim Taymans's avatar
Wim Taymans committed
84
#include "gstenumtypes.h"
85
#include "gstutils.h"
86
#include "gstquark.h"
Benjamin Otte's avatar
Benjamin Otte committed
87

88 89
#define GST_EVENT_SEQNUM(e) ((GstEvent*)e)->abidata.seqnum

90 91
static void gst_event_finalize (GstEvent * event);
static GstEvent *_gst_event_copy (GstEvent * event);
92

93 94
static GstMiniObjectClass *parent_class = NULL;

95 96 97
void
_gst_event_initialize (void)
{
98 99 100
  g_type_class_ref (gst_event_get_type ());
  g_type_class_ref (gst_seek_flags_get_type ());
  g_type_class_ref (gst_seek_type_get_type ());
101 102
}

103 104
typedef struct
{
105 106
  const gint type;
  const gchar *name;
107 108 109 110 111 112 113 114 115 116
  GQuark quark;
} GstEventQuarks;

static GstEventQuarks event_quarks[] = {
  {GST_EVENT_UNKNOWN, "unknown", 0},
  {GST_EVENT_FLUSH_START, "flush-start", 0},
  {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
  {GST_EVENT_EOS, "eos", 0},
  {GST_EVENT_NEWSEGMENT, "newsegment", 0},
  {GST_EVENT_TAG, "tag", 0},
117
  {GST_EVENT_BUFFERSIZE, "buffersize", 0},
118 119 120
  {GST_EVENT_QOS, "qos", 0},
  {GST_EVENT_SEEK, "seek", 0},
  {GST_EVENT_NAVIGATION, "navigation", 0},
121
  {GST_EVENT_LATENCY, "latency", 0},
122 123 124
  {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
  {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
  {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
125 126 127
  {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
  {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},

128 129 130
  {0, NULL, 0}
};

Stefan Kost's avatar
Stefan Kost committed
131 132 133 134 135 136
/**
 * gst_event_type_get_name:
 * @type: the event type
 *
 * Get a printable name for the given event type. Do not modify or free.
 *
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
137
 * Returns: a reference to the static name of the event.
Stefan Kost's avatar
Stefan Kost committed
138
 */
139 140 141 142 143 144 145 146 147 148 149 150
const gchar *
gst_event_type_get_name (GstEventType type)
{
  gint i;

  for (i = 0; event_quarks[i].name; i++) {
    if (type == event_quarks[i].type)
      return event_quarks[i].name;
  }
  return "unknown";
}

Stefan Kost's avatar
Stefan Kost committed
151 152 153 154 155 156 157 158
/**
 * gst_event_type_to_quark:
 * @type: the event type
 *
 * Get the unique quark for the given event type.
 *
 * Returns: the quark associated with the event type
 */
159 160 161 162 163 164 165 166 167 168 169 170
GQuark
gst_event_type_to_quark (GstEventType type)
{
  gint i;

  for (i = 0; event_quarks[i].name; i++) {
    if (type == event_quarks[i].type)
      return event_quarks[i].quark;
  }
  return 0;
}

171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188
/**
 * gst_event_type_get_flags:
 * @type: a #GstEventType
 *
 * Gets the #GstEventTypeFlags associated with @type.
 *
 * Returns: a #GstEventTypeFlags.
 */
GstEventTypeFlags
gst_event_type_get_flags (GstEventType type)
{
  GstEventTypeFlags ret;

  ret = type & ((1 << GST_EVENT_TYPE_SHIFT) - 1);

  return ret;
}

189 190 191 192 193 194 195
#define _do_init \
{ \
  gint i; \
  \
  for (i = 0; event_quarks[i].name; i++) { \
    event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name); \
  } \
196 197
}

198 199
G_DEFINE_TYPE_WITH_CODE (GstEvent, gst_event, GST_TYPE_MINI_OBJECT, _do_init);

200
static void
201
gst_event_class_init (GstEventClass * klass)
Wim Taymans's avatar
Wim Taymans committed
202
{
203
  parent_class = g_type_class_peek_parent (klass);
Wim Taymans's avatar
Wim Taymans committed
204

205 206
  klass->mini_object_class.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
  klass->mini_object_class.finalize =
207 208
      (GstMiniObjectFinalizeFunction) gst_event_finalize;
}
Wim Taymans's avatar
Wim Taymans committed
209

210
static void
211
gst_event_init (GstEvent * event)
212 213
{
  GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
Wim Taymans's avatar
Wim Taymans committed
214 215
}

216
static void
217
gst_event_finalize (GstEvent * event)
218
{
219 220 221
  g_return_if_fail (event != NULL);
  g_return_if_fail (GST_IS_EVENT (event));

222
  GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
223
      GST_EVENT_TYPE_NAME (event));
Wim Taymans's avatar
Wim Taymans committed
224

225 226
  if (GST_EVENT_SRC (event)) {
    gst_object_unref (GST_EVENT_SRC (event));
227
    GST_EVENT_SRC (event) = NULL;
228
  }
Wim Taymans's avatar
Wim Taymans committed
229 230 231
  if (event->structure) {
    gst_structure_set_parent_refcount (event->structure, NULL);
    gst_structure_free (event->structure);
232
  }
233

234
/*   GST_MINI_OBJECT_CLASS (parent_class)->finalize (GST_MINI_OBJECT (event)); */
235 236 237 238 239 240 241
}

static GstEvent *
_gst_event_copy (GstEvent * event)
{
  GstEvent *copy;

Wim Taymans's avatar
Wim Taymans committed
242
  copy = (GstEvent *) gst_mini_object_new (GST_TYPE_EVENT);
243

Wim Taymans's avatar
Wim Taymans committed
244 245
  GST_EVENT_TYPE (copy) = GST_EVENT_TYPE (event);
  GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
246
  GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
247

Wim Taymans's avatar
Wim Taymans committed
248 249 250 251 252 253
  if (GST_EVENT_SRC (event)) {
    GST_EVENT_SRC (copy) = gst_object_ref (GST_EVENT_SRC (event));
  }
  if (event->structure) {
    copy->structure = gst_structure_copy (event->structure);
    gst_structure_set_parent_refcount (copy->structure,
254
        &copy->mini_object.refcount);
255 256
  }
  return copy;
257 258
}

Wim Taymans's avatar
Wim Taymans committed
259 260
static GstEvent *
gst_event_new (GstEventType type)
261
{
Wim Taymans's avatar
Wim Taymans committed
262
  GstEvent *event;
263

Wim Taymans's avatar
Wim Taymans committed
264
  event = (GstEvent *) gst_mini_object_new (GST_TYPE_EVENT);
265

Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
266 267
  GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
      gst_event_type_get_name (type), type);
268

Wim Taymans's avatar
Wim Taymans committed
269 270 271
  event->type = type;
  event->src = NULL;
  event->structure = NULL;
272
  GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
273

Wim Taymans's avatar
Wim Taymans committed
274
  return event;
275 276
}

277
/**
Wim Taymans's avatar
Wim Taymans committed
278
 * gst_event_new_custom:
279
 * @type: The type of the new event
Wim Taymans's avatar
Wim Taymans committed
280 281
 * @structure: The structure for the event. The event will take ownership of
 * the structure.
282
 *
Wim Taymans's avatar
Wim Taymans committed
283 284 285
 * Create a new custom-typed event. This can be used for anything not
 * handled by other event-specific functions to pass an event to another
 * element.
286
 *
Wim Taymans's avatar
Wim Taymans committed
287 288 289 290 291 292 293 294
 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
 * assigning a free number and filling in the correct direction and
 * serialization flags.
 *
 * New custom events can also be created by subclassing the event type if
 * needed.
 *
 * Returns: The new custom event.
295
 */
296
GstEvent *
Wim Taymans's avatar
Wim Taymans committed
297
gst_event_new_custom (GstEventType type, GstStructure * structure)
298 299 300
{
  GstEvent *event;

301 302 303 304
  /* structure must not have a parent */
  if (structure)
    g_return_val_if_fail (structure->parent_refcount == NULL, NULL);

Wim Taymans's avatar
Wim Taymans committed
305 306 307 308 309
  event = gst_event_new (type);
  if (structure) {
    gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
    event->structure = structure;
  }
310
  return event;
311 312
}

313
/**
Wim Taymans's avatar
Wim Taymans committed
314 315
 * gst_event_get_structure:
 * @event: The #GstEvent.
316
 *
Wim Taymans's avatar
Wim Taymans committed
317
 * Access the structure of the event.
318
 *
Wim Taymans's avatar
Wim Taymans committed
319 320 321 322 323
 * Returns: The structure of the event. The structure is still
 * owned by the event, which means that you should not free it and
 * that the pointer becomes invalid when you free the event.
 *
 * MT safe.
324
 */
Wim Taymans's avatar
Wim Taymans committed
325 326
const GstStructure *
gst_event_get_structure (GstEvent * event)
327
{
Wim Taymans's avatar
Wim Taymans committed
328
  g_return_val_if_fail (GST_IS_EVENT (event), NULL);
329

Wim Taymans's avatar
Wim Taymans committed
330
  return event->structure;
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
/**
 * gst_event_has_name:
 * @event: The #GstEvent.
 * @name: name to check
 *
 * Checks if @event has the given @name. This function is usually used to
 * check the name of a custom event.
 *
 * Returns: %TRUE if @name matches the name of the event structure.
 *
 * Since: 0.10.20
 */
gboolean
gst_event_has_name (GstEvent * event, const gchar * name)
{
  g_return_val_if_fail (GST_IS_EVENT (event), FALSE);

  if (event->structure == NULL)
    return FALSE;

  return gst_structure_has_name (event->structure, name);
}

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
/**
 * gst_event_get_seqnum:
 * @event: A #GstEvent.
 *
 * Retrieve the sequence number of a event.
 *
 * Events have ever-incrementing sequence numbers, which may also be set
 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
 * indicate that a event corresponds to some other set of events or messages,
 * for example an EOS event corresponding to a SEEK event. It is considered good
 * practice to make this correspondence when possible, though it is not
 * required.
 *
 * Note that events and messages share the same sequence number incrementor;
 * two events or messages will never not have the same sequence number unless
 * that correspondence was made explicitly.
 *
 * Returns: The event's sequence number.
 *
 * MT safe.
 *
 * Since: 0.10.22
 */
guint32
gst_event_get_seqnum (GstEvent * event)
{
  g_return_val_if_fail (GST_IS_EVENT (event), -1);

  return GST_EVENT_SEQNUM (event);
}

/**
 * gst_event_set_seqnum:
 * @event: A #GstEvent.
 * @seqnum: A sequence number.
 *
 * Set the sequence number of a event.
 *
 * This function might be called by the creator of a event to indicate that the
 * event relates to other events or messages. See gst_event_get_seqnum() for
 * more information.
 *
 * MT safe.
 *
 * Since: 0.10.22
 */
void
gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
{
  g_return_if_fail (GST_IS_EVENT (event));

  GST_EVENT_SEQNUM (event) = seqnum;
}

410 411 412 413
/* FIXME 0.11: It would be nice to have flush events
 * that don't reset the running time in the sinks
 */

Wim Taymans's avatar
Wim Taymans committed
414
/**
Wim Taymans's avatar
Wim Taymans committed
415 416
 * gst_event_new_flush_start:
 *
417
 * Allocate a new flush start event. The flush start event can be sent
Wim Taymans's avatar
Wim Taymans committed
418
 * upstream and downstream and travels out-of-bounds with the dataflow.
419 420 421 422 423
 *
 * It marks pads as being flushing and will make them return
 * #GST_FLOW_WRONG_STATE when used for data flow with gst_pad_push(),
 * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and
 * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received
424
 * on a flushing pad will return %FALSE immediately.
Wim Taymans's avatar
Wim Taymans committed
425
 *
426 427
 * Elements should unlock any blocking functions and exit their streaming
 * functions as fast as possible when this event is received.
Wim Taymans's avatar
Wim Taymans committed
428
 *
429 430
 * This event is typically generated after a seek to flush out all queued data
 * in the pipeline so that the new media is played as soon as possible.
Wim Taymans's avatar
Wim Taymans committed
431
 *
Wim Taymans's avatar
Wim Taymans committed
432
 * Returns: A new flush start event.
Wim Taymans's avatar
Wim Taymans committed
433
 */
434
GstEvent *
Wim Taymans's avatar
Wim Taymans committed
435
gst_event_new_flush_start (void)
436
{
Wim Taymans's avatar
Wim Taymans committed
437
  return gst_event_new (GST_EVENT_FLUSH_START);
438 439
}

440
/**
Wim Taymans's avatar
Wim Taymans committed
441 442
 * gst_event_new_flush_stop:
 *
443
 * Allocate a new flush stop event. The flush stop event can be sent
Wim Taymans's avatar
Wim Taymans committed
444
 * upstream and downstream and travels out-of-bounds with the dataflow.
445
 * It is typically sent after sending a FLUSH_START event to make the
Wim Taymans's avatar
Wim Taymans committed
446
 * pads accept data again.
447
 *
Wim Taymans's avatar
Wim Taymans committed
448 449
 * Elements can process this event synchronized with the dataflow since
 * the preceeding FLUSH_START event stopped the dataflow.
450
 *
Wim Taymans's avatar
Wim Taymans committed
451 452 453 454
 * This event is typically generated to complete a seek and to resume
 * dataflow.
 *
 * Returns: A new flush stop event.
455
 */
456
GstEvent *
Wim Taymans's avatar
Wim Taymans committed
457
gst_event_new_flush_stop (void)
458
{
Wim Taymans's avatar
Wim Taymans committed
459
  return gst_event_new (GST_EVENT_FLUSH_STOP);
460 461
}

Wim Taymans's avatar
Wim Taymans committed
462
/**
Wim Taymans's avatar
Wim Taymans committed
463
 * gst_event_new_eos:
Wim Taymans's avatar
Wim Taymans committed
464
 *
Wim Taymans's avatar
Wim Taymans committed
465 466
 * Create a new EOS event. The eos event can only travel downstream
 * synchronized with the buffer flow. Elements that receive the EOS
467 468
 * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn
 * when data after the EOS event arrives.
Wim Taymans's avatar
Wim Taymans committed
469
 *
Jan Schmidt's avatar
Jan Schmidt committed
470
 * The EOS event will travel down to the sink elements in the pipeline
471
 * which will then post the #GST_MESSAGE_EOS on the bus after they have
Jan Schmidt's avatar
Jan Schmidt committed
472
 * finished playing any buffered data.
Wim Taymans's avatar
Wim Taymans committed
473
 *
474
 * When all sinks have posted an EOS message, an EOS message is
Wim Taymans's avatar
Wim Taymans committed
475 476 477
 * forwarded to the application.
 *
 * Returns: The new EOS event.
Wim Taymans's avatar
Wim Taymans committed
478
 */
Wim Taymans's avatar
Wim Taymans committed
479 480
GstEvent *
gst_event_new_eos (void)
481
{
Wim Taymans's avatar
Wim Taymans committed
482
  return gst_event_new (GST_EVENT_EOS);
483 484
}

485
/**
486
 * gst_event_new_new_segment:
487
 * @update: is this segment an update to a previous one
Wim Taymans's avatar
Wim Taymans committed
488 489
 * @rate: a new rate for playback
 * @format: The format of the segment values
490 491 492
 * @start: the start value of the segment
 * @stop: the stop value of the segment
 * @position: stream position
Wim Taymans's avatar
Wim Taymans committed
493
 *
494 495 496 497
 * Allocate a new newsegment event with the given format/values tripplets
 *
 * This method calls gst_event_new_new_segment_full() passing a default
 * value of 1.0 for applied_rate
Tim-Philipp Müller's avatar
Tim-Philipp Müller committed
498 499
 *
 * Returns: A new newsegment event.
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
 */
GstEvent *
gst_event_new_new_segment (gboolean update, gdouble rate, GstFormat format,
    gint64 start, gint64 stop, gint64 position)
{
  return gst_event_new_new_segment_full (update, rate, 1.0, format, start,
      stop, position);
}

/**
 * gst_event_parse_new_segment:
 * @event: The event to query
 * @update: A pointer to the update flag of the segment
 * @rate: A pointer to the rate of the segment
 * @format: A pointer to the format of the newsegment values
 * @start: A pointer to store the start value in
 * @stop: A pointer to store the stop value in
 * @position: A pointer to store the stream time in
 *
 * Get the update flag, rate, format, start, stop and position in the 
 * newsegment event. In general, gst_event_parse_new_segment_full() should
 * be used instead of this, to also retrieve the applied_rate value of the
 * segment. See gst_event_new_new_segment_full() for a full description 
 * of the newsegment event.
 */
void
gst_event_parse_new_segment (GstEvent * event, gboolean * update,
    gdouble * rate, GstFormat * format, gint64 * start,
    gint64 * stop, gint64 * position)
{
  gst_event_parse_new_segment_full (event, update, rate, NULL, format, start,
      stop, position);
}

/**
 * gst_event_new_new_segment_full:
 * @update: Whether this segment is an update to a previous one
 * @rate: A new rate for playback
 * @applied_rate: The rate factor which has already been applied
 * @format: The format of the segment values
 * @start: The start value of the segment
 * @stop: The stop value of the segment
 * @position: stream position
 *
 * Allocate a new newsegment event with the given format/values triplets.
Wim Taymans's avatar
Wim Taymans committed
545 546
 *
 * The newsegment event marks the range of buffers to be processed. All
547
 * data not within the segment range is not to be processed. This can be
548
 * used intelligently by plugins to apply more efficient methods of skipping
549 550
 * unneeded data. The valid range is expressed with the @start and @stop
 * values.
551
 *
552 553 554 555 556
 * The position value of the segment is used in conjunction with the start
 * value to convert the buffer timestamps into the stream time. This is 
 * usually done in sinks to report the current stream_time. 
 * @position represents the stream_time of a buffer carrying a timestamp of 
 * @start. @position cannot be -1.
557
 *
558
 * @start cannot be -1, @stop can be -1. If there
559
 * is a valid @stop given, it must be greater or equal the @start, including 
560
 * when the indicated playback @rate is < 0.
561 562 563 564 565 566 567 568
 *
 * The @applied_rate value provides information about any rate adjustment that
 * has already been made to the timestamps and content on the buffers of the 
 * stream. (@rate * @applied_rate) should always equal the rate that has been 
 * requested for playback. For example, if an element has an input segment 
 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust 
 * incoming timestamps and buffer content by half and output a newsegment event 
 * with @rate of 1.0 and @applied_rate of 2.0
569
 *
Wim Taymans's avatar
Wim Taymans committed
570 571
 * After a newsegment event, the buffer stream time is calculated with:
 *
572
 *   position + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
Wim Taymans's avatar
Wim Taymans committed
573 574
 *
 * Returns: A new newsegment event.
575 576
 *
 * Since: 0.10.6
577
 */
578
GstEvent *
579 580 581
gst_event_new_new_segment_full (gboolean update, gdouble rate,
    gdouble applied_rate, GstFormat format, gint64 start, gint64 stop,
    gint64 position)
582
{
583 584 585
  GstEvent *event;
  GstStructure *structure;

586
  g_return_val_if_fail (rate != 0.0, NULL);
587
  g_return_val_if_fail (applied_rate != 0.0, NULL);
588

589 590
  if (format == GST_FORMAT_TIME) {
    GST_CAT_INFO (GST_CAT_EVENT,
591
        "creating newsegment update %d, rate %lf, format GST_FORMAT_TIME, "
592
        "start %" GST_TIME_FORMAT ", stop %" GST_TIME_FORMAT
593 594 595
        ", position %" GST_TIME_FORMAT,
        update, rate, GST_TIME_ARGS (start),
        GST_TIME_ARGS (stop), GST_TIME_ARGS (position));
596 597
  } else {
    GST_CAT_INFO (GST_CAT_EVENT,
598
        "creating newsegment update %d, rate %lf, format %s, "
599
        "start %" G_GINT64_FORMAT ", stop %" G_GINT64_FORMAT ", position %"
600 601
        G_GINT64_FORMAT, update, rate, gst_format_get_name (format), start,
        stop, position);
602
  }
603

604 605 606 607
  g_return_val_if_fail (position != -1, NULL);
  g_return_val_if_fail (start != -1, NULL);
  if (stop != -1)
    g_return_val_if_fail (start <= stop, NULL);
608

609
  structure = gst_structure_id_new (GST_QUARK (EVENT_NEWSEGMENT),
610 611 612 613 614 615 616 617 618 619
      GST_QUARK (UPDATE), G_TYPE_BOOLEAN, update,
      GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
      GST_QUARK (APPLIED_RATE), G_TYPE_DOUBLE, applied_rate,
      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
      GST_QUARK (START), G_TYPE_INT64, start,
      GST_QUARK (STOP), G_TYPE_INT64, stop,
      GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
  event = gst_event_new_custom (GST_EVENT_NEWSEGMENT, structure);

  return event;
Wim Taymans's avatar
Wim Taymans committed
620
}
621

Wim Taymans's avatar
Wim Taymans committed
622
/**
623
 * gst_event_parse_new_segment_full:
Wim Taymans's avatar
Wim Taymans committed
624
 * @event: The event to query
625
 * @update: A pointer to the update flag of the segment
Wim Taymans's avatar
Wim Taymans committed
626
 * @rate: A pointer to the rate of the segment
627
 * @applied_rate: A pointer to the applied_rate of the segment
Wim Taymans's avatar
Wim Taymans committed
628
 * @format: A pointer to the format of the newsegment values
629 630 631
 * @start: A pointer to store the start value in
 * @stop: A pointer to store the stop value in
 * @position: A pointer to store the stream time in
Wim Taymans's avatar
Wim Taymans committed
632
 *
633 634 635 636 637
 * Get the update, rate, applied_rate, format, start, stop and 
 * position in the newsegment event. See gst_event_new_new_segment_full() 
 * for a full description of the newsegment event.
 *
 * Since: 0.10.6
Wim Taymans's avatar
Wim Taymans committed
638 639
 */
void
640 641 642
gst_event_parse_new_segment_full (GstEvent * event, gboolean * update,
    gdouble * rate, gdouble * applied_rate, GstFormat * format,
    gint64 * start, gint64 * stop, gint64 * position)
Wim Taymans's avatar
Wim Taymans committed
643 644
{
  const GstStructure *structure;
645

Wim Taymans's avatar
Wim Taymans committed
646 647 648 649
  g_return_if_fail (GST_IS_EVENT (event));
  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_NEWSEGMENT);

  structure = gst_event_get_structure (event);
650
  if (G_LIKELY (update))
651
    *update =
652 653
        g_value_get_boolean (gst_structure_id_get_value (structure,
            GST_QUARK (UPDATE)));
654
  if (G_LIKELY (rate))
655 656 657
    *rate =
        g_value_get_double (gst_structure_id_get_value (structure,
            GST_QUARK (RATE)));
658 659
  if (G_LIKELY (applied_rate))
    *applied_rate =
660 661
        g_value_get_double (gst_structure_id_get_value (structure,
            GST_QUARK (APPLIED_RATE)));
662
  if (G_LIKELY (format))
663 664 665
    *format =
        g_value_get_enum (gst_structure_id_get_value (structure,
            GST_QUARK (FORMAT)));
666
  if (G_LIKELY (start))
667 668 669
    *start =
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (START)));
670
  if (G_LIKELY (stop))
671 672 673
    *stop =
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (STOP)));
674
  if (G_LIKELY (position))
675
    *position =
676 677
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (POSITION)));
Wim Taymans's avatar
Wim Taymans committed
678
}
679

680 681
/**
 * gst_event_new_tag:
682
 * @taglist: metadata list. The event will take ownership of @taglist.
683 684
 *
 * Generates a metadata tag event from the given @taglist.
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
685
 *
686 687
 * Returns: a new #GstEvent
 */
Wim Taymans's avatar
Wim Taymans committed
688 689 690 691
GstEvent *
gst_event_new_tag (GstTagList * taglist)
{
  g_return_val_if_fail (taglist != NULL, NULL);
692

Wim Taymans's avatar
Wim Taymans committed
693
  return gst_event_new_custom (GST_EVENT_TAG, (GstStructure *) taglist);
694 695
}

696 697 698 699 700 701 702
/**
 * gst_event_parse_tag:
 * @event: a tag event
 * @taglist: pointer to metadata list
 *
 * Parses a tag @event and stores the results in the given @taglist location.
 */
Wim Taymans's avatar
Wim Taymans committed
703 704 705 706 707
void
gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
{
  g_return_if_fail (GST_IS_EVENT (event));
  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
708

Wim Taymans's avatar
Wim Taymans committed
709 710 711 712
  if (taglist)
    *taglist = (GstTagList *) event->structure;
}

713 714
/* buffersize event */
/**
715
 * gst_event_new_buffer_size:
Stefan Kost's avatar
Stefan Kost committed
716 717 718 719
 * @format: buffer format
 * @minsize: minimum buffer size
 * @maxsize: maximum buffer size
 * @async: thread behavior
720 721 722 723
 *
 * Create a new buffersize event. The event is sent downstream and notifies
 * elements that they should provide a buffer of the specified dimensions.
 *
724
 * When the @async flag is set, a thread boundary is prefered.
725 726 727 728
 *
 * Returns: a new #GstEvent
 */
GstEvent *
729
gst_event_new_buffer_size (GstFormat format, gint64 minsize,
730 731
    gint64 maxsize, gboolean async)
{
732 733 734
  GstEvent *event;
  GstStructure *structure;

735
  GST_CAT_INFO (GST_CAT_EVENT,
736 737
      "creating buffersize format %s, minsize %" G_GINT64_FORMAT
      ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
738
      minsize, maxsize, async);
739

740
  structure = gst_structure_id_new (GST_QUARK (EVENT_BUFFER_SIZE),
741 742 743 744 745 746 747
      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
      GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
      GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
      GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
  event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);

  return event;
748 749
}

Stefan Kost's avatar
Stefan Kost committed
750
/**
751
 * gst_event_parse_buffer_size:
Stefan Kost's avatar
Stefan Kost committed
752 753 754 755 756 757 758 759
 * @event: The event to query
 * @format: A pointer to store the format in
 * @minsize: A pointer to store the minsize in
 * @maxsize: A pointer to store the maxsize in
 * @async: A pointer to store the async-flag in
 *
 * Get the format, minsize, maxsize and async-flag in the buffersize event.
 */
760
void
761
gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
762 763 764 765 766 767
    gint64 * minsize, gint64 * maxsize, gboolean * async)
{
  const GstStructure *structure;

  g_return_if_fail (GST_IS_EVENT (event));
  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
768

769 770
  structure = gst_event_get_structure (event);
  if (format)
771 772 773
    *format =
        g_value_get_enum (gst_structure_id_get_value (structure,
            GST_QUARK (FORMAT)));
774 775
  if (minsize)
    *minsize =
776 777
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (MINSIZE)));
778 779
  if (maxsize)
    *maxsize =
780 781
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (MAXSIZE)));
782
  if (async)
783 784 785
    *async =
        g_value_get_boolean (gst_structure_id_get_value (structure,
            GST_QUARK (ASYNC)));
786 787
}

788
/**
Wim Taymans's avatar
Wim Taymans committed
789 790 791 792 793 794 795 796
 * gst_event_new_qos:
 * @proportion: the proportion of the qos message
 * @diff: The time difference of the last Clock sync
 * @timestamp: The timestamp of the buffer
 *
 * Allocate a new qos event with the given values.
 * The QOS event is generated in an element that wants an upstream
 * element to either reduce or increase its rate because of
797
 * high/low CPU load or other resource usage such as network performance.
798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813
 * Typically sinks generate these events for each buffer they receive.
 *
 * @proportion indicates the real-time performance of the streaming in the
 * element that generated the QoS event (usually the sink). The value is
 * generally computed based on more long term statistics about the streams
 * timestamps compared to the clock.
 * A value < 1.0 indicates that the upstream element is producing data faster
 * than real-time. A value > 1.0 indicates that the upstream element is not
 * producing data fast enough. 1.0 is the ideal @proportion value. The
 * proportion value can safely be used to lower or increase the quality of
 * the element.
 *
 * @diff is the difference against the clock in running time of the last
 * buffer that caused the element to generate the QOS event. A negative value
 * means that the buffer with @timestamp arrived in time. A positive value
 * indicates how late the buffer with @timestamp was.
814
 *
815
 * @timestamp is the timestamp of the last buffer that cause the element
816 817
 * to generate the QOS event. It is expressed in running time and thus an ever
 * increasing value.
818 819
 *
 * The upstream element can use the @diff and @timestamp values to decide
820 821
 * whether to process more buffers. For possitive @diff, all buffers with
 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
822 823
 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
 * result smaller than 0 is not allowed.
824 825 826
 *
 * The application can use general event probes to intercept the QoS
 * event and implement custom application specific QoS handling.
Wim Taymans's avatar
Wim Taymans committed
827 828
 *
 * Returns: A new QOS event.
829
 */
830
GstEvent *
Wim Taymans's avatar
Wim Taymans committed
831 832
gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
    GstClockTime timestamp)
833
{
834 835 836
  GstEvent *event;
  GstStructure *structure;

837 838 839
  /* diff must be positive or timestamp + diff must be positive */
  g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);

840
  GST_CAT_INFO (GST_CAT_EVENT,
841
      "creating qos proportion %lf, diff %" G_GINT64_FORMAT
842
      ", timestamp %" GST_TIME_FORMAT, proportion,
843
      diff, GST_TIME_ARGS (timestamp));
844

845
  structure = gst_structure_id_new (GST_QUARK (EVENT_QOS),
846 847 848 849 850 851
      GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
      GST_QUARK (DIFF), G_TYPE_INT64, diff,
      GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
  event = gst_event_new_custom (GST_EVENT_QOS, structure);

  return event;
Wim Taymans's avatar
Wim Taymans committed
852
}
853

Wim Taymans's avatar
Wim Taymans committed
854 855 856 857 858 859 860
/**
 * gst_event_parse_qos:
 * @event: The event to query
 * @proportion: A pointer to store the proportion in
 * @diff: A pointer to store the diff in
 * @timestamp: A pointer to store the timestamp in
 *
861 862
 * Get the proportion, diff and timestamp in the qos event. See
 * gst_event_new_qos() for more information about the different QoS values.
Wim Taymans's avatar
Wim Taymans committed
863 864 865 866 867 868
 */
void
gst_event_parse_qos (GstEvent * event, gdouble * proportion,
    GstClockTimeDiff * diff, GstClockTime * timestamp)
{
  const GstStructure *structure;
869

Wim Taymans's avatar
Wim Taymans committed
870 871
  g_return_if_fail (GST_IS_EVENT (event));
  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
872

Wim Taymans's avatar
Wim Taymans committed
873 874 875
  structure = gst_event_get_structure (event);
  if (proportion)
    *proportion =
876 877
        g_value_get_double (gst_structure_id_get_value (structure,
            GST_QUARK (PROPORTION)));
Wim Taymans's avatar
Wim Taymans committed
878
  if (diff)
879 880 881
    *diff =
        g_value_get_int64 (gst_structure_id_get_value (structure,
            GST_QUARK (DIFF)));
Wim Taymans's avatar
Wim Taymans committed
882 883
  if (timestamp)
    *timestamp =
884 885
        g_value_get_uint64 (gst_structure_id_get_value (structure,
            GST_QUARK (TIMESTAMP)));
886
}
887 888

/**
Wim Taymans's avatar
Wim Taymans committed
889 890 891
 * gst_event_new_seek:
 * @rate: The new playback rate
 * @format: The format of the seek values
Thomas Vander Stichele's avatar
Thomas Vander Stichele committed
892
 * @flags: The optional seek flags
893 894
 * @start_type: The type and flags for the new start position
 * @start: The value of the new start position
Wim Taymans's avatar
Wim Taymans committed
895 896 897 898 899
 * @stop_type: The type and flags for the new stop position
 * @stop: The value of the new stop position
 *
 * Allocate a new seek event with the given parameters.
 *
900 901 902
 * The seek event configures playback of the pipeline between @start to @stop
 * at the speed given in @rate, also called a playback segment.
 * The @start and @stop values are expressed in @format.
903
 *
Wim Taymans's avatar
Wim Taymans committed
904 905
 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
 * Negatives values means backwards playback. A value of 0.0 for the
906 907 908
 * rate is not allowed and should be accomplished instead by PAUSING the
 * pipeline.
 *
909 910 911
 * A pipeline has a default playback segment configured with a start
 * position of 0, a stop position of -1 and a rate of 1.0. The currently
 * configured playback segment can be queried with #GST_QUERY_SEGMENT. 
912
 *
913
 * @start_type and @stop_type specify how to adjust the currently configured 
914 915 916
 * start and stop fields in playback segment. Adjustments can be made relative
 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
 * means that the position should not be updated.
917
 *
918
 * When the rate is positive and @start has been updated, playback will start
919 920 921 922 923
 * from the newly configured start position. 
 *
 * For negative rates, playback will start from the newly configured stop
 * position (if any). If the stop position if updated, it must be different from
 * -1 for negative rates.
924 925 926 927
 *
 * It is not possible to seek relative to the current playback position, to do
 * this, PAUSE the pipeline, query the current playback position with
 * #GST_QUERY_POSITION and update the playback segment current position with a
928
 * #GST_SEEK_TYPE_SET to the desired position. 
929
 *
Wim Taymans's avatar
Wim Taymans committed
930
 * Returns: A new seek event.
931 932
 */
GstEvent *
Wim Taymans's avatar
Wim Taymans committed
933
gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
934
    GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
935
{
936 937 938
  GstEvent *event;
  GstStructure *structure;

939 940
  g_return_val_if_fail (rate != 0.0, NULL);

941 942 943
  if (format == GST_FORMAT_TIME) {
    GST_CAT_INFO (GST_CAT_EVENT,
        "creating seek rate %lf, format TIME, flags %d, "
944
        "start_type %d, start %" GST_TIME_FORMAT ", "
945
        "stop_type %d, stop %" GST_TIME_FORMAT,
946
        rate, flags, start_type, GST_TIME_ARGS (start),
947 948 949
        stop_type, GST_TIME_ARGS (stop));
  } else {
    GST_CAT_INFO (GST_CAT_EVENT,
950
        "creating seek rate %lf, format %s, flags %d, "
951
        "start_type %d, start %" G_GINT64_FORMAT ", "
952
        "stop_type %d, stop %" G_GINT64_FORMAT,
953 954
        rate, gst_format_get_name (format), flags, start_type, start, stop_type,
        stop);
955 956
  }

957
  structure = gst_structure_id_new (GST_QUARK (EVENT_SEEK),
958 959 960 961 962 963 964 965 966 967
      GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
      GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
      GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
      GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
      GST_QUARK (CUR), G_TYPE_INT64, start,
      GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
      GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
  event = gst_event_new_custom (GST_EVENT_SEEK, structure);

  return event;
Wim Taymans's avatar
Wim Taymans committed
968
}
969

970 971 972 973 974 975
/**
 * gst_event_parse_seek:
 * @event: a seek event
 * @rate: result location for the rate
 * @format: result location for the stream format
 * @flags:  result location for the #GstSeekFlags
976 977
 * @start_type: result location for the #GstSeekType of the start position
 * @start: result location for the start postion expressed in @format
978 979 980 981 982
 * @stop_type:  result location for the #GstSeekType of the stop position
 * @stop: result location for the stop postion expressed in @format
 *
 * Parses a seek @event and stores the results in the given result locations.
 */
Wim Taymans's avatar
Wim Taymans committed
983
void
984
gst_event_parse_seek (GstEvent * event, gdouble * rate,
985 986
    GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
    gint64 * start, GstSeekType * stop_type, gint64 * stop)
Wim Taymans's avatar
Wim Taymans committed
987 988
{
  const GstStructure *structure;
989

Wim Taymans's avatar
Wim Taymans committed
990 991
  g_return_if_fail (GST_IS_EVENT (event));
  g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
992

Wim Taymans's avatar
Wim Taymans committed
993 994
  structure = gst_event_get_structure (event);
  if (rate)
995 996 997
    *rate =
        g_value_get_double (gst_structure_id_get_value (structure,
            GST_QUARK (RATE)));
Wim Taymans's avatar
Wim Taymans committed
998
  if (format)
999 1000 1001
    *format =
        g_value_get_enum (gst_structure_id_get_value (structure,
            GST_QUARK (FORMAT)));
Wim Taymans's avatar
Wim Taymans committed
1002
  if (flags)
1003 1004 1005
    *flags =
        g_value_get_flags (gst_structure_id_get_value (structure,
            GST_QUARK (FLAGS)));
1006 1007
  if (start_type)
    *start_type =
1008 1009
        g_value_get_enum (gst_structure_id_get_value (structure,
            GST_QUARK (CUR_TYPE)));