/usr/share/gtk-doc/html/gst-plugins-base-libs-1.0/gst-plugins-base-libs-appsink.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 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>appsink: 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-app.html" title="App Library">
<link rel="prev" href="gst-plugins-base-libs-appsrc.html" title="appsrc">
<link rel="next" href="gstreamer-audio.html" title="Audio Library">
<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-appsink.description" class="shortcut">Description</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-app.html"><img src="up.png" width="16" height="16" border="0" alt="Up"></a></td>
<td><a accesskey="p" href="gst-plugins-base-libs-appsrc.html"><img src="left.png" width="16" height="16" border="0" alt="Prev"></a></td>
<td><a accesskey="n" href="gstreamer-audio.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-appsink"></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-appsink.top_of_page"></a>appsink</span></h2>
<p>appsink — Easy way for applications to extract samples from a
pipeline</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
</tr></table></div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.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-appsink.html#gst-app-sink-set-caps" title="gst_app_sink_set_caps ()">gst_app_sink_set_caps</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html"><span class="returnvalue">GstCaps</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-get-caps" title="gst_app_sink_get_caps ()">gst_app_sink_get_caps</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-appsink.html#gst-app-sink-is-eos" title="gst_app_sink_is_eos ()">gst_app_sink_is_eos</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-appsink.html#gst-app-sink-set-emit-signals" title="gst_app_sink_set_emit_signals ()">gst_app_sink_set_emit_signals</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-appsink.html#gst-app-sink-get-emit-signals" title="gst_app_sink_get_emit_signals ()">gst_app_sink_get_emit_signals</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-appsink.html#gst-app-sink-set-max-buffers" title="gst_app_sink_set_max_buffers ()">gst_app_sink_set_max_buffers</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#guint"><span class="returnvalue">guint</span></a>
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-get-max-buffers" title="gst_app_sink_get_max_buffers ()">gst_app_sink_get_max_buffers</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-appsink.html#gst-app-sink-set-drop" title="gst_app_sink_set_drop ()">gst_app_sink_set_drop</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-appsink.html#gst-app-sink-get-drop" title="gst_app_sink_get_drop ()">gst_app_sink_get_drop</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="returnvalue">GstSample</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-preroll" title="gst_app_sink_pull_preroll ()">gst_app_sink_pull_preroll</a> <span class="c_punctuation">()</span>
</td>
</tr>
<tr>
<td class="function_type">
<a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="returnvalue">GstSample</span></a> *
</td>
<td class="function_name">
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-sample" title="gst_app_sink_pull_sample ()">gst_app_sink_pull_sample</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-appsink.html#gst-app-sink-set-callbacks" title="gst_app_sink_set_callbacks ()">gst_app_sink_set_callbacks</a> <span class="c_punctuation">()</span>
</td>
</tr>
</tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.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-appsink.html#GstAppSinkCallbacks" title="GstAppSinkCallbacks">GstAppSinkCallbacks</a></td>
</tr></tbody>
</table></div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.includes"></a><h2>Includes</h2>
<pre class="synopsis">#include <gst/app/gstappsink.h>
</pre>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.description"></a><h2>Description</h2>
<p>Appsink is a sink plugin that supports many different methods for making
the application get a handle on the GStreamer data in a pipeline. Unlike
most GStreamer elements, Appsink provides external API functions.</p>
<p>appsink can be used by linking to the gstappsink.h header file to access the
methods or by using the appsink action signals and properties.</p>
<p>The normal way of retrieving samples from appsink is by using the
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-sample" title="gst_app_sink_pull_sample ()"><code class="function">gst_app_sink_pull_sample()</code></a> and <a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-preroll" title="gst_app_sink_pull_preroll ()"><code class="function">gst_app_sink_pull_preroll()</code></a> methods.
These methods block until a sample becomes available in the sink or when the
sink is shut down or reaches EOS.</p>
<p>Appsink will internally use a queue to collect buffers from the streaming
thread. If the application is not pulling samples fast enough, this queue
will consume a lot of memory over time. The "max-buffers" property can be
used to limit the queue size. The "drop" property controls whether the
streaming thread blocks or if older buffers are dropped when the maximum
queue size is reached. Note that blocking the streaming thread can negatively
affect real-time performance and should be avoided.</p>
<p>If a blocking behaviour is not desirable, setting the "emit-signals" property
to <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> will make appsink emit the "new-sample" and "new-preroll" signals
when a sample can be pulled without blocking.</p>
<p>The "caps" property on appsink can be used to control the formats that
appsink can receive. This property can contain non-fixed caps, the format of
the pulled samples can be obtained by getting the sample caps.</p>
<p>If one of the pull-preroll or pull-sample methods return <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, the appsink
is stopped or in the EOS state. You can check for the EOS state with the
"eos" property or with the <a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos" title="gst_app_sink_is_eos ()"><code class="function">gst_app_sink_is_eos()</code></a> method.</p>
<p>The eos signal can also be used to be informed when the EOS state is reached
to avoid polling.</p>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.functions_details"></a><h2>Functions</h2>
<div class="refsect2">
<a name="gst-app-sink-set-caps"></a><h3>gst_app_sink_set_caps ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_app_sink_set_caps (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>,
<em class="parameter"><code>const <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html"><span class="type">GstCaps</span></a> *caps</code></em>);</pre>
<p>Set the capabilities on the appsink element. This function takes
a copy of the caps structure. After calling this method, the sink will only
accept caps that match <em class="parameter"><code>caps</code></em>
. If <em class="parameter"><code>caps</code></em>
is non-fixed, or incomplete,
you must check the caps on the samples to get the actual used caps.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.2.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>caps</p></td>
<td class="parameter_description"><p>caps to set</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-get-caps"></a><h3>gst_app_sink_get_caps ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html"><span class="returnvalue">GstCaps</span></a> *
gst_app_sink_get_caps (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Get the configured caps on <em class="parameter"><code>appsink</code></em>
.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.3.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.3.6"></a><h4>Returns</h4>
<p> the <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html"><span class="type">GstCaps</span></a> accepted by the sink. <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a> after usage.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-is-eos"></a><h3>gst_app_sink_is_eos ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_app_sink_is_eos (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Check if <em class="parameter"><code>appsink</code></em>
is EOS, which is when no more samples can be pulled because
an EOS event was received.</p>
<p>This function also returns <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> when the appsink is not in the PAUSED or
PLAYING state.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.4.6"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.4.7"></a><h4>Returns</h4>
<p> <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if no more samples can be pulled and the appsink is EOS.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-set-emit-signals"></a><h3>gst_app_sink_set_emit_signals ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_app_sink_set_emit_signals (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</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> emit</code></em>);</pre>
<p>Make appsink emit the "new-preroll" and "new-sample" signals. This option is
by default disabled because signal emission is expensive and unneeded when
the application prefers to operate in pull mode.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.5.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>emit</p></td>
<td class="parameter_description"><p>the new state</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-get-emit-signals"></a><h3>gst_app_sink_get_emit_signals ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_app_sink_get_emit_signals (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Check if appsink will emit the "new-preroll" and "new-sample" signals.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.6.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.6.6"></a><h4>Returns</h4>
<p> <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if <em class="parameter"><code>appsink</code></em>
is emiting the "new-preroll" and "new-sample"
signals.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-set-max-buffers"></a><h3>gst_app_sink_set_max_buffers ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_app_sink_set_max_buffers (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="type">guint</span></a> max</code></em>);</pre>
<p>Set the maximum amount of buffers that can be queued in <em class="parameter"><code>appsink</code></em>
. After this
amount of buffers are queued in appsink, any more buffers will block upstream
elements until a sample is pulled from <em class="parameter"><code>appsink</code></em>
.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.7.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>max</p></td>
<td class="parameter_description"><p>the maximum number of buffers to queue</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-get-max-buffers"></a><h3>gst_app_sink_get_max_buffers ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guint"><span class="returnvalue">guint</span></a>
gst_app_sink_get_max_buffers (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Get the maximum amount of buffers that can be queued in <em class="parameter"><code>appsink</code></em>
.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.8.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.8.6"></a><h4>Returns</h4>
<p> The maximum amount of buffers that can be queued.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-set-drop"></a><h3>gst_app_sink_set_drop ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_app_sink_set_drop (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</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> drop</code></em>);</pre>
<p>Instruct <em class="parameter"><code>appsink</code></em>
to drop old buffers when the maximum amount of queued
buffers is reached.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.9.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>drop</p></td>
<td class="parameter_description"><p>the new state</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-get-drop"></a><h3>gst_app_sink_get_drop ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>
gst_app_sink_get_drop (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Check if <em class="parameter"><code>appsink</code></em>
will drop old buffers when the maximum amount of queued
buffers is reached.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.10.5"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.10.6"></a><h4>Returns</h4>
<p> <a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if <em class="parameter"><code>appsink</code></em>
is dropping old buffers when the queue is
filled.</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-pull-preroll"></a><h3>gst_app_sink_pull_preroll ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="returnvalue">GstSample</span></a> *
gst_app_sink_pull_preroll (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>Get the last preroll sample in <em class="parameter"><code>appsink</code></em>
. This was the sample that caused the
appsink to preroll in the PAUSED state. This sample can be pulled many times
and remains available to the application even after EOS.</p>
<p>This function is typically used when dealing with a pipeline in the PAUSED
state. Calling this function after doing a seek will give the sample right
after the seek position.</p>
<p>Note that the preroll sample will also be returned as the first sample
when calling <a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-sample" title="gst_app_sink_pull_sample ()"><code class="function">gst_app_sink_pull_sample()</code></a>.</p>
<p>If an EOS event was received before any buffers, this function returns
<a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. Use <a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos" title="gst_app_sink_is_eos ()"><code class="function">gst_app_sink_is_eos()</code></a> to check for the EOS condition.</p>
<p>This function blocks until a preroll sample or EOS is received or the appsink
element is set to the READY/NULL state.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.11.9"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.11.10"></a><h4>Returns</h4>
<p> a <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="type">GstSample</span></a> or NULL when the appsink is stopped or EOS.
Call <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html#gst-sample-unref"><code class="function">gst_sample_unref()</code></a> after usage. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-pull-sample"></a><h3>gst_app_sink_pull_sample ()</h3>
<pre class="programlisting"><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="returnvalue">GstSample</span></a> *
gst_app_sink_pull_sample (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>);</pre>
<p>This function blocks until a sample or EOS becomes available or the appsink
element is set to the READY/NULL state.</p>
<p>This function will only return samples when the appsink is in the PLAYING
state. All rendered buffers will be put in a queue so that the application
can pull samples at its own rate. Note that when the application does not
pull samples fast enough, the queued buffers could consume a lot of memory,
especially when dealing with raw video frames.</p>
<p>If an EOS event was received before any buffers, this function returns
<a href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>. Use <a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-is-eos" title="gst_app_sink_is_eos ()"><code class="function">gst_app_sink_is_eos()</code></a> to check for the EOS condition.</p>
<div class="refsect3">
<a name="id-1.2.5.5.7.12.7"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr></tbody>
</table></div>
</div>
<div class="refsect3">
<a name="id-1.2.5.5.7.12.8"></a><h4>Returns</h4>
<p> a <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="type">GstSample</span></a> or NULL when the appsink is stopped or EOS.
Call <a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html#gst-sample-unref"><code class="function">gst_sample_unref()</code></a> after usage. </p>
<p><span class="annotation">[<acronym title="Free data after the code is done."><span class="acronym">transfer full</span></acronym>]</span></p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="gst-app-sink-set-callbacks"></a><h3>gst_app_sink_set_callbacks ()</h3>
<pre class="programlisting"><span class="returnvalue">void</span>
gst_app_sink_set_callbacks (<em class="parameter"><code><span class="type">GstAppSink</span> *appsink</code></em>,
<em class="parameter"><code><a class="link" href="gst-plugins-base-libs-appsink.html#GstAppSinkCallbacks" title="GstAppSinkCallbacks"><span class="type">GstAppSinkCallbacks</span></a> *callbacks</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>,
<em class="parameter"><code><a href="/usr/share/gtk-doc/html/glib/glib-Datasets.html#GDestroyNotify"><span class="type">GDestroyNotify</span></a> notify</code></em>);</pre>
<p>Set callbacks which will be executed for each new preroll, new sample and eos.
This is an alternative to using the signals, it has lower overhead and is thus
less expensive, but also less flexible.</p>
<p>If callbacks are installed, no signals will be emitted for performance
reasons.</p>
<p><span class="annotation">[<acronym title="Exposed in C code, not necessarily available in other languages."><span class="acronym">skip</span></acronym>]</span></p>
<div class="refsect3">
<a name="id-1.2.5.5.7.13.7"></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>appsink</p></td>
<td class="parameter_description"><p>a <span class="type">GstAppSink</span></p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>callbacks</p></td>
<td class="parameter_description"><p>the callbacks</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>user_data</p></td>
<td class="parameter_description"><p>a user_data argument for the callbacks</p></td>
<td class="parameter_annotations"> </td>
</tr>
<tr>
<td class="parameter_name"><p>notify</p></td>
<td class="parameter_description"><p>a destroy notify function</p></td>
<td class="parameter_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.other_details"></a><h2>Types and Values</h2>
<div class="refsect2">
<a name="GstAppSinkCallbacks"></a><h3>GstAppSinkCallbacks</h3>
<pre class="programlisting">typedef struct {
void (*eos) (GstAppSink *appsink, gpointer user_data);
GstFlowReturn (*new_preroll) (GstAppSink *appsink, gpointer user_data);
GstFlowReturn (*new_sample) (GstAppSink *appsink, gpointer user_data);
} GstAppSinkCallbacks;
</pre>
<p>A set of callbacks that can be installed on the appsink with
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-set-callbacks" title="gst_app_sink_set_callbacks ()"><code class="function">gst_app_sink_set_callbacks()</code></a>.</p>
<div class="refsect3">
<a name="id-1.2.5.5.8.2.5"></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><em class="structfield"><code><a name="GstAppSinkCallbacks.eos"></a>eos</code></em> ()</p></td>
<td class="struct_member_description"><p>Called when the end-of-stream has been reached. This callback
is called from the streaming thread.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstAppSinkCallbacks.new-preroll"></a>new_preroll</code></em> ()</p></td>
<td class="struct_member_description"><p>Called when a new preroll sample is available.
This callback is called from the streaming thread.
The new preroll sample can be retrieved with
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-preroll" title="gst_app_sink_pull_preroll ()"><code class="function">gst_app_sink_pull_preroll()</code></a> either from this callback
or from any other thread.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
<tr>
<td class="struct_member_name"><p><em class="structfield"><code><a name="GstAppSinkCallbacks.new-sample"></a>new_sample</code></em> ()</p></td>
<td class="struct_member_description"><p>Called when a new sample is available.
This callback is called from the streaming thread.
The new sample can be retrieved with
<a class="link" href="gst-plugins-base-libs-appsink.html#gst-app-sink-pull-sample" title="gst_app_sink_pull_sample ()"><code class="function">gst_app_sink_pull_sample()</code></a> either from this callback
or from any other thread.</p></td>
<td class="struct_member_annotations"> </td>
</tr>
</tbody>
</table></div>
</div>
</div>
</div>
<div class="refsect1">
<a name="gst-plugins-base-libs-appsink.see-also"></a><h2>See Also</h2>
<p><a href="/usr/share/gtk-doc/html/gstreamer-1.0/GstSample.html"><span class="type">GstSample</span></a>, <a href="/usr/share/gtk-doc/html/gstreamer-libs-1.0/GstBaseSink.html"><span class="type">GstBaseSink</span></a>, appsrc</p>
</div>
</div>
<div class="footer">
<hr>Generated by GTK-Doc V1.24</div>
</body>
</html>
|