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
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>GstVideoContextInterface</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.76.1">
<link rel="home" href="index.html" title="GStreamer Bad Plugins 1.0 Library Reference Manual">
<link rel="up" href="video.html" title="Base video element classes">
<link rel="prev" href="gst-plugins-bad-libs-gstbasevideoutils.html" title="gstbasevideoutils">
<link rel="next" href="gst-plugins-bad-libs-GstSurfaceBuffer.html" title="GstSurfaceBuffer">
<meta name="generator" content="GTK-Doc V1.18 (XML mode)">
<link rel="stylesheet" href="style.css" type="text/css">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table class="navigation" id="top" width="100%" summary="Navigation header" cellpadding="2" cellspacing="2">
<tr valign="middle">
<td><a accesskey="p" href="gst-plugins-bad-libs-gstbasevideoutils.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td>
<td><a accesskey="u" href="video.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td>
<th width="100%" align="center">GStreamer Bad Plugins 1.0 Library Reference Manual</th>
<td><a accesskey="n" href="gst-plugins-bad-libs-GstSurfaceBuffer.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td>
</tr>
<tr><td colspan="5" class="shortcuts">
<a href="#gst-plugins-bad-libs-GstVideoContextInterface.synopsis" class="shortcut">Top</a>
|
<a href="#gst-plugins-bad-libs-GstVideoContextInterface.description" class="shortcut">Description</a>
</td></tr>
</table>
<div class="refentry">
<a name="gst-plugins-bad-libs-GstVideoContextInterface"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gst-plugins-bad-libs-GstVideoContextInterface.top_of_page"></a>GstVideoContextInterface</span></h2>
<p>GstVideoContextInterface — Interface to handle video library context</p>
</td>
<td valign="top" align="right"></td>
</tr></table></div>
<div class="refsynopsisdiv">
<a name="gst-plugins-bad-libs-GstVideoContextInterface.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">#define <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GST-IS-VIDEO-CONTEXT:CAPS" title="GST_IS_VIDEO_CONTEXT()">GST_IS_VIDEO_CONTEXT</a> (obj)
<a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext">GstVideoContext</a>;
struct <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContextInterface" title="struct GstVideoContextInterface">GstVideoContextInterface</a>;
<a href="http://library.gnome.org/devel/gobject/unstable/gobject-Type-Information.html#GType"><span class="returnvalue">GType</span></a> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-iface-get-type" title="gst_video_context_iface_get_type ()">gst_video_context_iface_get_type</a> (<em class="parameter"><code><span class="type">void</span></code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context" title="gst_video_context_set_context ()">gst_video_context_set_context</a> (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context-string" title="gst_video_context_set_context_string ()">gst_video_context_set_context_string</a>
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context-pointer" title="gst_video_context_set_context_pointer ()">gst_video_context_set_context_pointer</a>
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context-object" title="gst_video_context_set_context_object ()">gst_video_context_set_context_object</a>
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-prepare" title="gst_video_context_prepare ()">gst_video_context_prepare</a> (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **types</code></em>);
<a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-message-parse-prepare" title="gst_video_context_message_parse_prepare ()">gst_video_context_message_parse_prepare</a>
(<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#GstMessage"><span class="type">GstMessage</span></a> *message</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> ***types</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> **ctx</code></em>);
<a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="returnvalue">GstQuery</span></a> * <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-new" title="gst_video_context_query_new ()">gst_video_context_query_new</a> (<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **types</code></em>);
<a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-run-query" title="gst_video_context_run_query ()">gst_video_context_run_query</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a> *element</code></em>,
<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>);
const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> ** <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-get-supported-types" title="gst_video_context_query_get_supported_types ()">gst_video_context_query_get_supported_types</a>
(<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-parse-value" title="gst_video_context_query_parse_value ()">gst_video_context_query_parse_value</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> **value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-set-value" title="gst_video_context_query_set_value ()">gst_video_context_query_set_value</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-set-string" title="gst_video_context_query_set_string ()">gst_video_context_query_set_string</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-set-pointer" title="gst_video_context_query_set_pointer ()">gst_video_context_query_set_pointer</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> value</code></em>);
<span class="returnvalue">void</span> <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-query-set-object" title="gst_video_context_query_set_object ()">gst_video_context_query_set_object</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *value</code></em>);
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-bad-libs-GstVideoContextInterface.description"></a><h2>Description</h2>
<p>
The Video Context interface enable sharing video context (such as display
name, X11 Display, VA-API Display, etc) between neighboor elements and the
application.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
The GstVideoContext interface is unstable API and may change in future.
One can define GST_USE_UNSTABLE_API to acknowledge and avoid this warning.
</div>
<p>
</p>
<p>
</p>
<div class="refsect2">
<a name="idp12143472"></a><h3>For Element</h3>
<p>
This interface shall be implement by group of elements that need to share
a specific video context (like VDPAU, LibVA, OpenGL elements) or by video
sink in order to let the application select appropriate display information
(like the X11 display name) when those sink are auto-plugged.
</p>
<p>
Along with implementing the interface, elements will need to query
neighboor elements or send message to the application when preparing
the context (see <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-prepare" title="gst_video_context_prepare ()"><code class="function">gst_video_context_prepare()</code></a>). They also need to reply
to the neighboors element queries, so the context can be shared without
the application help.
</p>
<p>
Elements that are guarantied to have both upstream and downstream
neighboors element implementing the <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> (like the gloverlay
element in gst-plugins-opengl) is not required to also implement the
interface. Relying on neighboors query shall be sufficient (see
<a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-run-query" title="gst_video_context_run_query ()"><code class="function">gst_video_context_run_query()</code></a>).
</p>
<p>
The query is an application query with a structure name set to
"prepare-video-context" and an array of supported video context types set
in the field named "types". This query shall be send downstream and
upstream, iterating the pads in order to find neighboors regardless of a
static (sink to src) or a dynamic (src to sink) activation. Element should
used the helpers method <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-prepare" title="gst_video_context_prepare ()"><code class="function">gst_video_context_prepare()</code></a> (or
<a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-run-query" title="gst_video_context_run_query ()"><code class="function">gst_video_context_run_query()</code></a> if no GstVideoContext interface) to
correctly execute the query . The result is set using the query helper
functions, the structures fields name being "video-context-type" as
string and "video-context" as a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a>.
</p>
<p>
If the query is not handled by any neighboor, the element should ask the
application using the "prepare-video-context" message. The application
may then use the interface to set the video context information. If no
context was set, the element shall create one using default configuration.
Elements with multiple src or sink pad shall implement proper locking to
prevent the race of parallel queries being replied.
</p>
<p>
Well known video-context are: "x11-display-name" a string representing the
X11 display to use, "x11-display" the X11 Display structure, "va-display",
the VADisplay structure and more.
</p>
</div>
<p>
</p>
<p>
</p>
<div class="refsect2">
<a name="idp12155728"></a><h3>For Application</h3>
<p>
In the case there is no neighboor element with video context to share,
the element will first turn toward the application, by sending a
"prepare-video-context" message. This message is sent along with a list
of supported display types. The application can optionally reply to this
message by calling appropriate setter through the <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
interface. If the application supports more then one video context type,
it should choose the first one to occure in the supported list. It's
important to remember that the message is delivered from the streaming
thread, and appropriate locking should be considered. If the application
does not have a video context to share, the element will simply allocate
one base on default settings. Usually, only applications using OpenGL
base sink, or running on special X11 display need to share a video context.
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
Applications sharing X11 Display structure should always initialize the
X11 threading support using <code class="function">XInitThreads()</code> as GStreamer will need to
manipulate the display from a separeate threads.
</div>
<p>
</p>
<div class="refsect2">
<a name="idp12160224"></a><h3>Example using ClutterVideoGstVideoSink</h3>
<p>
This example is for user of ClutterGstVideoSink element, the
ClutterGstPlayer object transparently handle this.
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>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</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc ppc">#if CLUTTER_WINDOWING_X11</span>
<span class="gtkdoc kwb">static</span> GstBusSyncReply
<span class="function">on_sync_message</span> <span class="gtkdoc opt">(</span>GstBus <span class="gtkdoc opt">*</span> bus<span class="gtkdoc opt">,</span> GstMessage <span class="gtkdoc opt">*</span> message<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
Display <span class="gtkdoc opt">*</span>display <span class="gtkdoc opt">=</span> user_data<span class="gtkdoc opt">;</span>
GstVideoContext <span class="gtkdoc opt">*</span>context<span class="gtkdoc opt">;</span>
<span class="gtkdoc kwb">const</span> gchar <span class="gtkdoc opt">**</span>types<span class="gtkdoc opt">;</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span><span class="function"><a href="../gst-plugins-bad-libs-1.0/gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-message-parse-prepare">gst_video_context_message_parse_prepare</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">, &</span>types<span class="gtkdoc opt">, &</span>context<span class="gtkdoc opt">)) {</span>
gint i<span class="gtkdoc opt">;</span>
<span class="keyword">for</span> <span class="gtkdoc opt">(</span>i <span class="gtkdoc opt">=</span> <span class="number">0</span><span class="gtkdoc opt">;</span> types<span class="gtkdoc opt">[</span>i<span class="gtkdoc opt">];</span> i<span class="gtkdoc opt">++) {</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(!</span><span class="function">strcmp</span><span class="gtkdoc opt">(</span>types<span class="gtkdoc opt">[</span>i<span class="gtkdoc opt">],</span> <span class="string">"x11-display"</span><span class="gtkdoc opt">)) {</span>
<span class="function"><a href="../gst-plugins-bad-libs-1.0/gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context-pointer">gst_video_context_set_context_pointer</a></span> <span class="gtkdoc opt">(</span>context<span class="gtkdoc opt">,</span> <span class="string">"x11-display"</span><span class="gtkdoc opt">,</span> display<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">else if</span> <span class="gtkdoc opt">(!</span><span class="function">strcmp</span><span class="gtkdoc opt">(</span>types<span class="gtkdoc opt">[</span>i<span class="gtkdoc opt">],</span> <span class="string">"x11-display-name"</span><span class="gtkdoc opt">)) {</span>
<span class="function"><a href="../gst-plugins-bad-libs-1.0/gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context-string">gst_video_context_set_context_string</a></span> <span class="gtkdoc opt">(</span>context<span class="gtkdoc opt">,</span> <span class="string">"x11-display-name"</span><span class="gtkdoc opt">,</span>
<span class="function">DisplayString</span> <span class="gtkdoc opt">(</span>display<span class="gtkdoc opt">));</span>
<span class="gtkdoc opt">}</span> <span class="keyword">else</span> <span class="gtkdoc opt">{</span>
<span class="keyword">continue</span><span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#gst-message-unref">gst_message_unref</a></span> <span class="gtkdoc opt">(</span>message<span class="gtkdoc opt">);</span>
<span class="keyword">return</span> GST_BUS_DROP<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc opt">}</span>
<span class="keyword">return</span> GST_BUS_PASS<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc ppc">#endif</span>
gint
<span class="function">main</span> <span class="gtkdoc opt">(</span>gint argc<span class="gtkdoc opt">,</span> gchar <span class="gtkdoc opt">**</span>argv<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
GstBin <span class="gtkdoc opt">*</span>pipeline<span class="gtkdoc opt">;</span>
GstBus <span class="gtkdoc opt">*</span>bus<span class="gtkdoc opt">;</span>
<span class="gtkdoc opt">...</span>
bus <span class="gtkdoc opt">=</span> <span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPipeline.html#gst-pipeline-get-bus">gst_pipeline_get_bus</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_PIPELINE</span> <span class="gtkdoc opt">(</span>pipeline<span class="gtkdoc opt">));</span>
<span class="gtkdoc ppc">#if CLUTTER_WINDOWING_X11</span>
<span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBus.html#gst-bus-set-sync-handler">gst_bus_set_sync_handler</a></span> <span class="gtkdoc opt">(</span>priv<span class="gtkdoc opt">-></span>bus<span class="gtkdoc opt">,</span> on_sync_message<span class="gtkdoc opt">,</span>
<span class="function">clutter_x11_get_default_display</span> <span class="gtkdoc opt">(),</span> NULL<span class="gtkdoc opt">);</span>
<span class="gtkdoc ppc">#endif</span>
<span class="function"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstObject.html#gst-object-unref">gst_object_unref</a></span> <span class="gtkdoc opt">(</span><span class="function">GST_OBJECT</span> <span class="gtkdoc opt">(</span>priv<span class="gtkdoc opt">-></span>bus<span class="gtkdoc opt">));</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<p>
</p>
</div>
<div class="refsect1">
<a name="gst-plugins-bad-libs-GstVideoContextInterface.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GST-IS-VIDEO-CONTEXT:CAPS"></a><h3>GST_IS_VIDEO_CONTEXT()</h3>
<pre class="programlisting">#define GST_IS_VIDEO_CONTEXT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_VIDEO_CONTEXT))
</pre>
</div>
<hr>
<div class="refsect2">
<a name="GstVideoContext"></a><h3>GstVideoContext</h3>
<pre class="programlisting">typedef struct _GstVideoContext GstVideoContext;</pre>
<p>
Opaque <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> data structure.
</p>
</div>
<hr>
<div class="refsect2">
<a name="GstVideoContextInterface"></a><h3>struct GstVideoContextInterface</h3>
<pre class="programlisting">struct GstVideoContextInterface {
GTypeInterface parent;
/* virtual functions */
void (*set_context) (GstVideoContext * context,
const gchar * type,
const GValue * value);
};
</pre>
<p>
<a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContextInterface" title="struct GstVideoContextInterface"><span class="type">GstVideoContextInterface</span></a> interface.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Type-Information.html#GTypeInterface"><span class="type">GTypeInterface</span></a> <em class="structfield"><code><a name="GstVideoContextInterface.parent"></a>parent</code></em>;</span></p></td>
<td>parent interface type.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GstVideoContextInterface.set-context"></a>set_context</code></em> ()</span></p></td>
<td>vmethod to set video context.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-iface-get-type"></a><h3>gst_video_context_iface_get_type ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Type-Information.html#GType"><span class="returnvalue">GType</span></a> gst_video_context_iface_get_type (<em class="parameter"><code><span class="type">void</span></code></em>);</pre>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-set-context"></a><h3>gst_video_context_set_context ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_set_context (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *value</code></em>);</pre>
<p>
This is a wrapper for the <code class="function">set_context()</code> virtual method. It is suggested to
use one of the helpers to avoid having to manipulate <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>an element implementing <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the type of display being set</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> containing the context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-set-context-string"></a><h3>gst_video_context_set_context_string ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_set_context_string
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *value</code></em>);</pre>
<p>
This helper is commonly used for setting video context represented by a
string like the X11 display name ("x11-display-name")/
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>an element implementing <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the type of display being set</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>string</code></em> :</span></p></td>
<td>a string representing the video context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-set-context-pointer"></a><h3>gst_video_context_set_context_pointer ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_set_context_pointer
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> value</code></em>);</pre>
<p>
This helper is used for setting video context using a pointer, typically to
a structure like the X11 Display ("x11-display") or the VADisplay
("vaapi-display").
</p>
<div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Note</h3>
Users of X11 Display should ensure that <code class="function">XInitThreads()</code> was called before
opening the display.
</div>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>an element implementing <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the type of display being set</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>pointer</code></em> :</span></p></td>
<td>a pointer to the video context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-set-context-object"></a><h3>gst_video_context_set_context_object ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_set_context_object
(<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *value</code></em>);</pre>
<p>
This is for video context that are <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a>, this helper allow taking
benifit of the <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> refcounting. It is particularly handy for element
to have refcounting as the order in which element will stop using the
display is not defined.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>an element implementing <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the type of display being set</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>object</code></em> :</span></p></td>
<td>a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> resenting the display</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-prepare"></a><h3>gst_video_context_prepare ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_prepare (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> *context</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **types</code></em>);</pre>
<p>
This method run "prepare-video-context" custom query dowstream, and
upstream. If * the query has a reply, it sets the context value using
<a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-set-context" title="gst_video_context_set_context ()"><code class="function">gst_video_context_set_context()</code></a>. Otherwise, it sends a
"prepare-video-context" message to the application. The element can then
continue video context initialization.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>an element implementing <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> interface</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>types</code></em> :</span></p></td>
<td>an array of supported types, prefered first</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-message-parse-prepare"></a><h3>gst_video_context_message_parse_prepare ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_video_context_message_parse_prepare
(<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#GstMessage"><span class="type">GstMessage</span></a> *message</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> ***types</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a> **ctx</code></em>);</pre>
<p>
This helper shall be used by application to simply handling of the
"prepare-video-context" message.
</p>
<p>
Rerturns: <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#FALSE:CAPS"><span class="type">FALSE</span></a> is the message was not valid "prepare-video-context"
element message, otherwise <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><span class="type">TRUE</span></a> with <em class="parameter"><code>types</code></em> and <em class="parameter"><code>context</code></em> set.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>message</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstMessage.html#GstMessage"><span class="type">GstMessage</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>types</code></em> :</span></p></td>
<td>return value for supported types</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>context</code></em> :</span></p></td>
<td>return value for the element the implements <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-new"></a><h3>gst_video_context_query_new ()</h3>
<pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="returnvalue">GstQuery</span></a> * gst_video_context_query_new (<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **types</code></em>);</pre>
<p>
Create a new custom <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> with structure name "prepare-video-context".
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>types</code></em> :</span></p></td>
<td>a string array of video context types</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-run-query"></a><h3>gst_video_context_run_query ()</h3>
<pre class="programlisting"><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_video_context_run_query (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a> *element</code></em>,
<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>);</pre>
<p>
This helper runs the query on each downstream, then upstream pads in an
element. This is called by <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#gst-video-context-prepare" title="gst_video_context_prepare ()"><code class="function">gst_video_context_prepare()</code></a>. This method is only
used directly within elements that are required to have two neighboors
elements with appropriate video context. This would be the case of
specialized filters that only manipulate non-raw buffers (e.g.
gldeinterlace). Those elements do not have to implement <a class="link" href="gst-plugins-bad-libs-GstVideoContextInterface.html#GstVideoContext" title="GstVideoContext"><span class="type">GstVideoContext</span></a>
interface.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>element</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-get-supported-types"></a><h3>gst_video_context_query_get_supported_types ()</h3>
<pre class="programlisting">const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="returnvalue">gchar</span></a> ** gst_video_context_query_get_supported_types
(<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>);</pre>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>An array of supported video context types</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-parse-value"></a><h3>gst_video_context_query_parse_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_query_parse_value (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> **type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> **value</code></em>);</pre>
<p>
Helper to extract the video context type and value from a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>return video context type</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>return video context <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-set-value"></a><h3>gst_video_context_query_set_value ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_query_set_value (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> *value</code></em>);</pre>
<p>
Helper to set the video context as a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> inside the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the video context type</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-Generic-values.html#GValue"><span class="type">GValue</span></a> set with video context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-set-string"></a><h3>gst_video_context_query_set_string ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_query_set_string (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *value</code></em>);</pre>
<p>
Helper to set the video context as a string inside the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the video context type</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>a string representing the video context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-set-pointer"></a><h3>gst_video_context_query_set_pointer ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_query_set_pointer (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> value</code></em>);</pre>
<p>
Helper to set the video context as a <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> inside the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the video context type</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>a <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> representing the video context</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-context-query-set-object"></a><h3>gst_video_context_query_set_object ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span> gst_video_context_query_set_object (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a> *query</code></em>,
<em class="parameter"><code>const <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gchar"><span class="type">gchar</span></a> *type</code></em>,
<em class="parameter"><code><a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> *value</code></em>);</pre>
<p>
Helper to set the video context as a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> inside the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>query</code></em> :</span></p></td>
<td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstQuery.html#GstQuery"><span class="type">GstQuery</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>the video context type</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>value</code></em> :</span></p></td>
<td>a <a href="http://library.gnome.org/devel/gobject/unstable/gobject-The-Base-Object-Type.html#GObject"><span class="type">GObject</span></a> representing the video context</td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="footer">
<hr>
Generated by GTK-Doc V1.18</div>
</body>
</html>
|
