/usr/share/gtk-doc/html/gst-plugins-base-libs-1.0/gst-plugins-base-libs-gstvideooverlay.html is in gstreamer1.0-plugins-base-doc 1.8.0-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>gstvideooverlay: GStreamer Base Plugins 1.0 Library Reference Manual</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="GStreamer Base Plugins 1.0 Library Reference Manual">
<link rel="up" href="gstreamer-video.html" title="Video Library">
<link rel="prev" href="gst-plugins-base-libs-gstvideoorientation.html" title="gstvideoorientation">
<link rel="next" href="gst-plugins-base-libs-GstVideoDecoder.html" title="GstVideoDecoder">
<meta name="generator" content="GTK-Doc V1.24 (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="5"><tr valign="middle">
<td width="100%" align="left" class="shortcuts">
<a href="#" class="shortcut">Top</a><span id="nav_description"> <span class="dim">|</span>
<a href="#gst-plugins-base-libs-gstvideooverlay.description" class="shortcut">Description</a></span><span id="nav_hierarchy"> <span class="dim">|</span>
<a href="#gst-plugins-base-libs-gstvideooverlay.object-hierarchy" class="shortcut">Object Hierarchy</a></span>
</td>
<td><a accesskey="h" href="index.html"><img src="home.png" width="16" height="16" border="0" alt="Home"></a></td>
<td><a accesskey="u" href="gstreamer-video.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="gst-plugins-base-libs-gstvideoorientation.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="gst-plugins-base-libs-GstVideoDecoder.html"><img src="right.png" width="16" height="16" border="0" alt="Next"></a></td>
</tr></table>
<div class="refentry">
<a name="gst-plugins-base-libs-gstvideooverlay"></a><div class="titlepage"></div>
<div class="refnamediv"><table width="100%"><tr>
<td valign="top">
<h2><span class="refentrytitle"><a name="gst-plugins-base-libs-gstvideooverlay.top_of_page"></a>gstvideooverlay</span></h2>
<p>gstvideooverlay — Interface for setting/getting a window system resource
on elements supporting it to configure a window into which to render a
video.</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.functions"></a><h2>Functions</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="functions_return">
<col class="functions_name">
</colgroup>
<tbody>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-got-window-handle" title="gst_video_overlay_got_window_handle ()">gst_video_overlay_got_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()">gst_video_overlay_set_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-prepare-window-handle" title="gst_video_overlay_prepare_window_handle ()">gst_video_overlay_prepare_window_handle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-expose" title="gst_video_overlay_expose ()">gst_video_overlay_expose</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<span class="returnvalue">void</span>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-handle-events" title="gst_video_overlay_handle_events ()">gst_video_overlay_handle_events</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-render-rectangle" title="gst_video_overlay_set_render_rectangle ()">gst_video_overlay_set_render_rectangle</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-is-video-overlay-prepare-window-handle-message" title="gst_is_video_overlay_prepare_window_handle_message ()">gst_is_video_overlay_prepare_window_handle_message</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<a name="GstVideoOverlay"></a><div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.other"></a><h2>Types and Values</h2>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="name">
<col class="description">
</colgroup>
<tbody>
<tr>
<td class="datatype_keyword"> </td>
<td class="function_name"><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay-struct" title="GstVideoOverlay">GstVideoOverlay</a></td>
</tr>
<tr>
<td class="datatype_keyword">struct</td>
<td class="function_name"><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlayInterface" title="struct GstVideoOverlayInterface">GstVideoOverlayInterface</a></td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="screen"> GInterface
<span class="lineart">╰──</span> GstVideoOverlay
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include <gst/video/videooverlay.h>
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.description"></a><h2>Description</h2>
<div class="refsect2">
<a name="id-1.2.15.16.8.2"></a><p>
The <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface is used for 2 main purposes :
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>
To get a grab on the Window where the video sink element is going to render.
This is achieved by either being informed about the Window identifier that
the video sink element generated, or by forcing the video sink element to use
a specific Window identifier for rendering.
</p></li>
<li class="listitem"><p>
To force a redrawing of the latest video frame the video sink element
displayed on the Window. Indeed if the <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstPipeline.html"><span class="type">GstPipeline</span></a> is in <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstElement.html#GST-STATE-PAUSED:CAPS"><span class="type">GST_STATE_PAUSED</span></a>
state, moving the Window around will damage its content. Application
developers will want to handle the Expose events themselves and force the
video sink element to refresh the Window's content.
</p></li>
</ul></div>
<p>
</p>
<p>
Using the Window created by the video sink is probably the simplest scenario,
in some cases, though, it might not be flexible enough for application
developers if they need to catch events such as mouse moves and button
clicks.
</p>
<p>
Setting a specific Window identifier on the video sink element is the most
flexible solution but it has some issues. Indeed the application needs to set
its Window identifier at the right time to avoid internal Window creation
from the video sink element. To solve this issue a <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstMessage.html"><span class="type">GstMessage</span></a> is posted on
the bus to inform the application that it should set the Window identifier
immediately. Here is an example on how to do that correctly:
</p>
<div class="informalexample"><pre class="programlisting">
static GstBusSyncReply
create_window (GstBus * bus, GstMessage * message, GstPipeline * pipeline)
{
// ignore anything but 'prepare-window-handle' element messages
if (!gst_is_video_overlay_prepare_window_handle_message (message))
return GST_BUS_PASS;
win = XCreateSimpleWindow (disp, root, 0, 0, 320, 240, 0, 0, 0);
XSetWindowBackgroundPixmap (disp, win, None);
XMapRaised (disp, win);
XSync (disp, FALSE);
gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message)),
win);
gst_message_unref (message);
return GST_BUS_DROP;
}
...
int
main (int argc, char **argv)
{
...
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) create_window, pipeline,
NULL);
...
}
</pre></div>
<p>
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.15.16.8.3"></a><h3>Two basic usage scenarios</h3>
<p>
There are two basic usage scenarios: in the simplest case, the application
uses <span class="type">playbin</span> or <span class="type">plasink</span> or knows exactly what particular element is used
for video output, which is usually the case when the application creates
the videosink to use (e.g. <span class="type">xvimagesink</span>, <span class="type">ximagesink</span>, etc.) itself; in this
case, the application can just create the videosink element, create and
realize the window to render the video on and then
call <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> directly with the XID or native
window handle, before starting up the pipeline.
As <span class="type">playbin</span> and <span class="type">playsink</span> implement the video overlay interface and proxy
it transparently to the actual video sink even if it is created later, this
case also applies when using these elements.
</p>
<p>
In the other and more common case, the application does not know in advance
what GStreamer video sink element will be used for video output. This is
usually the case when an element such as <span class="type">autovideosink</span> is used.
In this case, the video sink element itself is created
asynchronously from a GStreamer streaming thread some time after the
pipeline has been started up. When that happens, however, the video sink
will need to know right then whether to render onto an already existing
application window or whether to create its own window. This is when it
posts a prepare-window-handle message, and that is also why this message needs
to be handled in a sync bus handler which will be called from the streaming
thread directly (because the video sink will need an answer right then).
</p>
<p>
As response to the prepare-window-handle element message in the bus sync
handler, the application may use <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> to tell
the video sink to render onto an existing window surface. At this point the
application should already have obtained the window handle / XID, so it
just needs to set it. It is generally not advisable to call any GUI toolkit
functions or window system functions from the streaming thread in which the
prepare-window-handle message is handled, because most GUI toolkits and
windowing systems are not thread-safe at all and a lot of care would be
required to co-ordinate the toolkit and window system calls of the
different threads (Gtk+ users please note: prior to Gtk+ 2.18
<code class="function">GDK_WINDOW_XID()</code> was just a simple structure access, so generally fine to do
within the bus sync handler; this macro was changed to a function call in
Gtk+ 2.18 and later, which is likely to cause problems when called from a
sync handler; see below for a better approach without <code class="function">GDK_WINDOW_XID()</code>
used in the callback).
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.15.16.8.4"></a><h3>GstVideoOverlay and Gtk+</h3>
<p>
</p>
<div class="informalexample"><pre class="programlisting">
#include <gst/video/videooverlay.h>
#include <gtk/gtk.h>
#ifdef GDK_WINDOWING_X11
#include <gdk/gdkx.h> // for GDK_WINDOW_XID
#endif
#ifdef GDK_WINDOWING_WIN32
#include <gdk/gdkwin32.h> // for GDK_WINDOW_HWND
#endif
...
static guintptr video_window_handle = 0;
...
static GstBusSyncReply
bus_sync_handler (GstBus * bus, GstMessage * message, gpointer user_data)
{
// ignore anything but 'prepare-window-handle' element messages
if (!gst_is_video_overlay_prepare_window_handle_message (message))
return GST_BUS_PASS;
if (video_window_handle != 0) {
GstVideoOverlay *overlay;
// GST_MESSAGE_SRC (message) will be the video sink element
overlay = GST_VIDEO_OVERLAY (GST_MESSAGE_SRC (message));
gst_video_overlay_set_window_handle (overlay, video_window_handle);
} else {
g_warning ("Should have obtained video_window_handle by now!");
}
gst_message_unref (message);
return GST_BUS_DROP;
}
...
static void
video_widget_realize_cb (GtkWidget * widget, gpointer data)
{
#if GTK_CHECK_VERSION(2,18,0)
// Tell Gtk+/Gdk to create a native window for this widget instead of
// drawing onto the parent widget.
// This is here just for pedagogical purposes, GDK_WINDOW_XID will call
// it as well in newer Gtk versions
if (!gdk_window_ensure_native (widget->window))
g_error ("Couldn't create native window needed for GstVideoOverlay!");
#endif
#ifdef GDK_WINDOWING_X11
{
gulong xid = GDK_WINDOW_XID (gtk_widget_get_window (video_window));
video_window_handle = xid;
}
#endif
#ifdef GDK_WINDOWING_WIN32
{
HWND wnd = GDK_WINDOW_HWND (gtk_widget_get_window (video_window));
video_window_handle = (guintptr) wnd;
}
#endif
}
...
int
main (int argc, char **argv)
{
GtkWidget *video_window;
GtkWidget *app_window;
...
app_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
...
video_window = gtk_drawing_area_new ();
g_signal_connect (video_window, "realize",
G_CALLBACK (video_widget_realize_cb), NULL);
gtk_widget_set_double_buffered (video_window, FALSE);
...
// usually the video_window will not be directly embedded into the
// application window like this, but there will be many other widgets
// and the video window will be embedded in one of them instead
gtk_container_add (GTK_CONTAINER (ap_window), video_window);
...
// show the GUI
gtk_widget_show_all (app_window);
// realize window now so that the video window gets created and we can
// obtain its XID/HWND before the pipeline is started up and the videosink
// asks for the XID/HWND of the window to render onto
gtk_widget_realize (video_window);
// we should have the XID/HWND now
g_assert (video_window_handle != 0);
...
// set up sync handler for setting the xid once the pipeline is started
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
gst_bus_set_sync_handler (bus, (GstBusSyncHandler) bus_sync_handler, NULL,
NULL);
gst_object_unref (bus);
...
gst_element_set_state (pipeline, GST_STATE_PLAYING);
...
}
</pre></div>
<p>
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.15.16.8.5"></a><h3>GstVideoOverlay and Qt</h3>
<p>
</p>
<div class="informalexample"><pre class="programlisting">
#include <glib.h>
#include <gst/gst.h>
#include <gst/video/videooverlay.h>
#include <QApplication>
#include <QTimer>
#include <QWidget>
int main(int argc, char *argv[])
{
if (!g_thread_supported ())
g_thread_init (NULL);
gst_init (&argc, &argv);
QApplication app(argc, argv);
app.connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit ()));
// prepare the pipeline
GstElement *pipeline = gst_pipeline_new ("xvoverlay");
GstElement *src = gst_element_factory_make ("videotestsrc", NULL);
GstElement *sink = gst_element_factory_make ("xvimagesink", NULL);
gst_bin_add_many (GST_BIN (pipeline), src, sink, NULL);
gst_element_link (src, sink);
// prepare the ui
QWidget window;
window.resize(320, 240);
window.show();
WId xwinid = window.winId();
gst_video_overlay_set_window_handle (GST_VIDEO_OVERLAY (sink), xwinid);
// run the pipeline
GstStateChangeReturn sret = gst_element_set_state (pipeline,
GST_STATE_PLAYING);
if (sret == GST_STATE_CHANGE_FAILURE) {
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
// Exit application
QTimer::singleShot(0, QApplication::activeWindow(), SLOT(quit()));
}
int ret = app.exec();
window.hide();
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
return ret;
}
</pre></div>
<p>
</p>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gst-video-overlay-got-window-handle"></a><h3>gst_video_overlay_got_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_got_window_handle (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guintptr"><span class="type">guintptr</span></a> handle</code></em>);</pre>
<p>This will post a "have-window-handle" element message on the bus.</p>
<p>This function should only be used by video overlay plugin developers.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.2.6"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> which got a window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle</p></td>
<td class="parameter_description"><p>a platform-specific handle referencing the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-set-window-handle"></a><h3>gst_video_overlay_set_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_set_window_handle (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guintptr"><span class="type">guintptr</span></a> handle</code></em>);</pre>
<p>This will call the video overlay's set_window_handle method. You
should use this method to tell to an overlay to display video output to a
specific window (e.g. an XWindow on X11). Passing 0 as the <em class="parameter"><code>handle</code></em>
will
tell the overlay to stop using that window and create an internal one.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.3.5"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to set the window on.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle</p></td>
<td class="parameter_description"><p>a handle referencing the window.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-prepare-window-handle"></a><h3>gst_video_overlay_prepare_window_handle ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_prepare_window_handle
(<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>);</pre>
<p>This will post a "prepare-window-handle" element message on the bus
to give applications an opportunity to call
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a> before a plugin creates its own
window.</p>
<p>This function should only be used by video overlay plugin developers.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.4.6"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> which does not yet have an Window handle set</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-expose"></a><h3>gst_video_overlay_expose ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_expose (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>);</pre>
<p>Tell an overlay that it has been exposed. This will redraw the current frame
in the drawable even if the pipeline is PAUSED.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.5.5"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to expose.</p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-handle-events"></a><h3>gst_video_overlay_handle_events ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_video_overlay_handle_events (<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> handle_events</code></em>);</pre>
<p>Tell an overlay that it should handle events from the window system. These
events are forwarded upstream as navigation events. In some window system,
events are not propagated in the window hierarchy if a client is listening
for them. This method allows you to disable events handling completely
from the <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.6.5"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> to expose.</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>handle_events</p></td>
<td class="parameter_description"><p>a <a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> indicating if events should be handled or not.</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-video-overlay-set-render-rectangle"></a><h3>gst_video_overlay_set_render_rectangle ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_video_overlay_set_render_rectangle
(<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> *overlay</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> x</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> y</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> width</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"><span class="type">gint</span></a> height</code></em>);</pre>
<p>Configure a subregion as a video target within the window set by
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-set-window-handle" title="gst_video_overlay_set_window_handle ()"><code class="function">gst_video_overlay_set_window_handle()</code></a>. If this is not used or not supported
the video will fill the area of the window set as the overlay to 100%.
By specifying the rectangle, the video can be overlayed to a specific region
of that window only. After setting the new rectangle one should call
<a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#gst-video-overlay-expose" title="gst_video_overlay_expose ()"><code class="function">gst_video_overlay_expose()</code></a> to force a redraw. To unset the region pass -1 for
the <em class="parameter"><code>width</code></em>
and <em class="parameter"><code>height</code></em>
parameters.</p>
<p>This method is needed for non fullscreen video overlay in UI toolkits that
do not support subwindows.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.7.6"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody>
<tr>
<td class="parameter_name"><p>overlay</p></td>
<td class="parameter_description"><p>a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>x</p></td>
<td class="parameter_description"><p>the horizontal offset of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>y</p></td>
<td class="parameter_description"><p>the vertical offset of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>width</p></td>
<td class="parameter_description"><p>the width of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>height</p></td>
<td class="parameter_description"><p>the height of the render area inside the window</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.15.16.9.7.7"></a><h4>Returns</h4>
<p> <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> if not supported by the sink.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-is-video-overlay-prepare-window-handle-message"></a><h3>gst_is_video_overlay_prepare_window_handle_message ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_is_video_overlay_prepare_window_handle_message
(<em class="parameter"><code><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstMessage.html"><span class="type">GstMessage</span></a> *msg</code></em>);</pre>
<p>Convenience function to check if the given message is a
"prepare-window-handle" message from a <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a>.</p>
<div class="refsect3">
<a name="id-1.2.15.16.9.8.5"></a><h4>Parameters</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="150px" class="parameters_name">
<col class="parameters_description">
<col width="200px" class="parameters_annotations">
</colgroup>
<tbody><tr>
<td class="parameter_name"><p>msg</p></td>
<td class="parameter_description"><p>a <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstMessage.html"><span class="type">GstMessage</span></a></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.15.16.9.8.6"></a><h4>Returns</h4>
<p> whether <em class="parameter"><code>msg</code></em>
is a "prepare-window-handle" message</p>
</div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-gstvideooverlay.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstVideoOverlay-struct"></a><h3>GstVideoOverlay</h3>
<pre class="programlisting">typedef struct _GstVideoOverlay GstVideoOverlay;</pre>
<p>Opaque <a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface structure</p>
</div>
<hr>
<div class="refsect2">
<a name="GstVideoOverlayInterface"></a><h3>struct GstVideoOverlayInterface</h3>
<pre class="programlisting">struct GstVideoOverlayInterface {
GTypeInterface iface;
/* virtual functions */
void (*expose) (GstVideoOverlay *overlay);
void (*handle_events) (GstVideoOverlay *overlay, gboolean handle_events);
void (*set_render_rectangle) (GstVideoOverlay *overlay,
gint x, gint y,
gint width, gint height);
void (*set_window_handle) (GstVideoOverlay *overlay, guintptr handle);
};
</pre>
<p><a class="link" href="gst-plugins-base-libs-gstvideooverlay.html#GstVideoOverlay"><span class="type">GstVideoOverlay</span></a> interface</p>
<div class="refsect3">
<a name="id-1.2.15.16.10.3.5"></a><h4>Members</h4>
<div class="informaltable"><table class="informaltable" width="100%" border="0">
<colgroup>
<col width="300px" class="struct_members_name">
<col class="struct_members_description">
<col width="200px" class="struct_members_annotations">
</colgroup>
<tbody>
<tr>
<td class="struct_member_name"><p><a href="/usr/share/gtk-doc/html/gobject/gobject-Type-Information.html#GTypeInterface"><span class="type">GTypeInterface</span></a> <em class="structfield"><code><a name="GstVideoOverlayInterface.iface"></a>iface</code></em>;</p></td>
<td class="struct_member_description"><p>parent interface type.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.expose"></a>expose</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to handle expose events</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.handle-events"></a>handle_events</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to handle events</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.set-render-rectangle"></a>set_render_rectangle</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to set the render rectangle</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstVideoOverlayInterface.set-window-handle"></a>set_window_handle</code></em> ()</p></td>
<td class="struct_member_description"><p>virtual method to configure the window handle</p></td>
<td class="struct_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.24</div>
</body>
</html>
|