1 <!-- ##### SECTION Title ##### -->
4 <!-- ##### SECTION Short_Description ##### -->
7 <!-- ##### SECTION Long_Description ##### -->
9 The event classes are used to construct and query events.
13 Events are usually created with gst_event_new() which takes the event type as an argument.
14 properties specific to the event can be set afterwards with the provided macros.
15 The event should be unreferenced with gst_event_unref().
18 gst_event_new_seek() is a usually used to create a seek event and it takes the
19 needed parameters for a seek event.
22 gst_event_new_flush() creates a new flush event.
25 <!-- ##### SECTION See_Also ##### -->
30 <!-- ##### ENUM GstEventType ##### -->
32 The different major types of events.
35 @GST_EVENT_UNKNOWN: unknown event.
36 @GST_EVENT_EOS: an end-of-stream event.
37 @GST_EVENT_FLUSH: a flush event.
38 @GST_EVENT_EMPTY: an empty event.
39 @GST_EVENT_DISCONTINUOUS: a discontinuous event to indicate the stream has a discontinuity.
40 @GST_EVENT_QOS: a quality of service event
41 @GST_EVENT_SEEK: a seek event.
42 @GST_EVENT_SEEK_SEGMENT: a segment seek with start and stop position
43 @GST_EVENT_SEGMENT_DONE: the event that will be emited when the segment seek has ended
44 @GST_EVENT_SIZE: a size suggestion for a peer element
45 @GST_EVENT_RATE: adjust the output rate of an element
46 @GST_EVENT_FILLER: a dummy event that should be ignored by plugins
47 @GST_EVENT_TS_OFFSET: an event to set the time offset on buffers
48 @GST_EVENT_INTERRUPT: mainly used by _get based elements when they were interrupted
49 while waiting for a buffer.
51 <!-- ##### MACRO GST_EVENT_TYPE ##### -->
56 @event: The event to query.
59 <!-- ##### MACRO GST_EVENT_SRC ##### -->
61 The source object that generated this event
64 @event: The event to query
67 <!-- ##### MACRO GST_EVENT_TIMESTAMP ##### -->
69 Get the timestamp of the event.
72 @event: The event to query.
75 <!-- ##### ENUM GstEventFlag ##### -->
77 Event flags are used when querying for supported events
80 @GST_EVENT_FLAG_NONE: no value
81 @GST_RATE_FLAG_NEGATIVE: indicates negative rates are supported
83 <!-- ##### ENUM GstSeekType ##### -->
85 The different types of seek events. When constructing a seek event a format,
86 a seek method and optional flags are OR-ed together. The seek event is then
87 inserted into the graph with #gst_pad_send_event() or #gst_element_send_event().
90 Following example illustrates how to insert a seek event (1 second in the stream)
97 event = gst_event_new_seek (
98 GST_FORMAT_TIME | /* seek on time */
99 GST_SEEK_METHOD_SET | /* set the absolute position */
100 GST_SEEK_FLAG_FLUSH, /* flush any pending data */
101 1 * GST_SECOND); /* the seek offset (1 second) */
103 res = gst_element_send_event (GST_ELEMENT (osssink), event);
105 g_warning ("seek failed");
111 @GST_SEEK_METHOD_CUR: Seek to an relative position
112 @GST_SEEK_METHOD_SET: Seek to an absolute position
113 @GST_SEEK_METHOD_END: Seek relative to the end of the stream
114 @GST_SEEK_FLAG_FLUSH: Flush any pending data while seeking
115 @GST_SEEK_FLAG_ACCURATE: Seek as accuratly as possible
116 @GST_SEEK_FLAG_KEY_UNIT: Seek to a nearby key unit
117 @GST_SEEK_FLAG_SEGMENT_LOOP: Loop between start and stop in a segmented seek
119 <!-- ##### ENUM GstSeekAccuracy ##### -->
121 The seekaccuracy gives more information of how the seek was performed,
122 if the seek was accurate or fuzzy.
125 @GST_SEEK_CERTAIN: The seek was exact
126 @GST_SEEK_FUZZY: The seek was fuzzy, exact position can not be guaranteed
128 <!-- ##### MACRO GST_EVENT_SEEK_TYPE ##### -->
130 Get the seektype of the GST_EVENT_SEEK.
133 @event: The event to query.
136 <!-- ##### MACRO GST_EVENT_SEEK_FORMAT ##### -->
138 The format of the seek value
141 @event: The event operate on
144 <!-- ##### MACRO GST_EVENT_SEEK_METHOD ##### -->
146 The seek method to use as one of #GstSeekType
149 @event: The event operate on
152 <!-- ##### MACRO GST_EVENT_SEEK_FLAGS ##### -->
154 The optional seek flags
157 @event: The event operate on
160 <!-- ##### MACRO GST_EVENT_SEEK_OFFSET ##### -->
162 Get the offset of the seek event.
165 @event: The event to query.
168 <!-- ##### MACRO GST_EVENT_SEEK_ACCURACY ##### -->
170 Indicates how accurate the event was performed.
173 @event: The event to query
176 <!-- ##### MACRO GST_SEEK_FLAGS_MASK ##### -->
178 Mask for the flags in the GstSeekType
183 <!-- ##### MACRO GST_SEEK_FLAGS_SHIFT ##### -->
185 Shift for the flags in the GstSeekType
190 <!-- ##### MACRO GST_SEEK_FORMAT_MASK ##### -->
192 Mask for the format in the GstSeekType
197 <!-- ##### MACRO GST_SEEK_FORMAT_SHIFT ##### -->
199 Shift for the format in the GstSeekType
204 <!-- ##### MACRO GST_SEEK_METHOD_MASK ##### -->
206 Mask for the method in the GstSeekType
211 <!-- ##### MACRO GST_SEEK_METHOD_SHIFT ##### -->
213 Shift for the method in the GstSeekType
218 <!-- ##### MACRO GST_EVENT_DISCONT_NEW_MEDIA ##### -->
220 Flag that indicates the discont event was because of a new media
224 @event: The event to operate on
227 <!-- ##### MACRO GST_EVENT_DISCONT_OFFSET ##### -->
229 The offset of the discont event. A discont evetn can hold up to 8 different
233 @event: The event to query
234 @i: The offset/value pair.
237 <!-- ##### MACRO GST_EVENT_DISCONT_OFFSET_LEN ##### -->
239 Get the number of offset/value pairs this event has.
242 @event: The event to query.
245 <!-- ##### MACRO GST_EVENT_RATE_VALUE ##### -->
247 Get access to the rate vale field
250 @event: The event to query
253 <!-- ##### MACRO GST_EVENT_SEEK_ENDOFFSET ##### -->
255 The event stop position for a segment seek
258 @event: The event to query
261 <!-- ##### MACRO GST_EVENT_SIZE_FORMAT ##### -->
263 The format of the size event.
266 @event: The event to query
269 <!-- ##### MACRO GST_EVENT_SIZE_VALUE ##### -->
271 The value of the size event
274 @event: The event to query
277 <!-- ##### MACRO GST_EVENT_IS_INTERRUPT ##### -->
279 Check if the event is an interrupt event
282 @event: The event to check
285 <!-- ##### MACRO GST_EVENT_TRACE_NAME ##### -->
287 The name used for memory allocation tracing
292 <!-- ##### STRUCT GstEvent ##### -->
302 <!-- ##### FUNCTION gst_event_new ##### -->
311 <!-- ##### MACRO gst_event_copy ##### -->
313 Copy the event using the event specific copy function
316 @ev: The event to copy
317 @Returns: A new event that is a copy of the given input event
320 <!-- ##### MACRO gst_event_ref ##### -->
322 Increase the refcount of this event
325 @ev: The event to refcount
328 <!-- ##### MACRO gst_event_ref_by_count ##### -->
330 Increase the refcount of the event with the given value
333 @ev: The event to refcount
334 @c: The value to add to the refcount
337 <!-- ##### MACRO gst_event_unref ##### -->
339 Decrease the refcount of an event, freeing it if the refcount reaches 0
342 @ev: The event to unref
345 <!-- ##### FUNCTION gst_event_new_seek ##### -->
355 <!-- ##### FUNCTION gst_event_new_segment_seek ##### -->
366 <!-- ##### FUNCTION gst_event_new_size ##### -->
376 <!-- ##### FUNCTION gst_event_new_discontinuous ##### -->
387 <!-- ##### FUNCTION gst_event_discont_get_value ##### -->
398 <!-- ##### MACRO gst_event_new_filler ##### -->
400 Create a new dummy event that should be ignored
405 <!-- ##### MACRO gst_event_new_flush ##### -->
407 Create a new flush event.
412 <!-- ##### FUNCTION gst_event_masks_contains ##### -->
422 <!-- ##### MACRO GST_EVENT_MASK_FUNCTION ##### -->
424 A convenience macro to create event mask functions
427 @type: The type of the first argument of the function
428 @functionname: the name of the function
429 @...: event masks, the last element is marked with 0