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| <a href="#gst-plugins-base-libs-appsink.synopsis" class="shortcut">Top</a> |
| | |
| <a href="#gst-plugins-base-libs-appsink.description" class="shortcut">Description</a> |
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| <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 valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsynopsisdiv"> |
| <a name="gst-plugins-base-libs-appsink.synopsis"></a><h2>Synopsis</h2> |
| <pre class="synopsis"> |
| #include <gst/app/gstappsink.h> |
| |
| <span class="returnvalue">void</span> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> *caps</code></em>); |
| <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> * <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</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-base-libs-appsink.html#gst-app-sink-is-eos" title="gst_app_sink_is_eos ()">gst_app_sink_is_eos</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <span class="returnvalue">void</span> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> emit</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-base-libs-appsink.html#gst-app-sink-get-emit-signals" title="gst_app_sink_get_emit_signals ()">gst_app_sink_get_emit_signals</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <span class="returnvalue">void</span> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="type">guint</span></a> max</code></em>); |
| <a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="returnvalue">guint</span></a> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <span class="returnvalue">void</span> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="type">gboolean</span></a> drop</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-base-libs-appsink.html#gst-app-sink-get-drop" title="gst_app_sink_get_drop ()">gst_app_sink_get_drop</a> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstSample.html#GstSample"><span class="returnvalue">GstSample</span></a> * <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstSample.html#GstSample"><span class="returnvalue">GstSample</span></a> * <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>); |
| <a class="link" href="gst-plugins-base-libs-appsink.html#GstAppSinkCallbacks" title="GstAppSinkCallbacks">GstAppSinkCallbacks</a>; |
| <span class="returnvalue">void</span> <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> (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/glib-Datasets.html#GDestroyNotify"><span class="type">GDestroyNotify</span></a> notify</code></em>); |
| </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="http://library.gnome.org/devel/glib/unstable/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="http://library.gnome.org/devel/glib/unstable/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> |
| <p> |
| Last reviewed on 2008-12-17 (0.10.22) |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-base-libs-appsink.details"></a><h2>Details</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><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code>const <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><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, you must check the caps |
| on the buffers to get the actual used caps. |
| </p> |
| <div class="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>caps</code></em> :</span></p></td> |
| <td>caps to set</td> |
| </tr> |
| </tbody> |
| </table></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="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="returnvalue">GstCaps</span></a> * gst_app_sink_get_caps (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>);</pre> |
| <p> |
| Get the configured caps on <em class="parameter"><code>appsink</code></em>. |
| </p> |
| <div class="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#GstCaps"><span class="type">GstCaps</span></a> accepted by the sink. <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstCaps.html#gst-caps-unref"><code class="function">gst_caps_unref()</code></a> after usage.</td> |
| </tr> |
| </tbody> |
| </table></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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_app_sink_is_eos (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> |
| <a href="http://library.gnome.org/devel/glib/unstable/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if no more samples can be pulled and the appsink is EOS.</td> |
| </tr> |
| </tbody> |
| </table></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><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>emit</code></em> :</span></p></td> |
| <td>the new state</td> |
| </tr> |
| </tbody> |
| </table></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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_app_sink_get_emit_signals (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>);</pre> |
| <p> |
| Check if appsink will emit the "new-preroll" and "new-sample" signals. |
| </p> |
| <div class="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> |
| <a href="http://library.gnome.org/devel/glib/unstable/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.</td> |
| </tr> |
| </tbody> |
| </table></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><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>max</code></em> :</span></p></td> |
| <td>the maximum number of buffers to queue</td> |
| </tr> |
| </tbody> |
| </table></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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#guint"><span class="returnvalue">guint</span></a> gst_app_sink_get_max_buffers (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>The maximum amount of buffers that can be queued.</td> |
| </tr> |
| </tbody> |
| </table></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><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *appsink</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>drop</code></em> :</span></p></td> |
| <td>the new state</td> |
| </tr> |
| </tbody> |
| </table></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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> gst_app_sink_get_drop (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td> |
| <a href="http://library.gnome.org/devel/glib/unstable/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.</td> |
| </tr> |
| </tbody> |
| </table></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="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstSample.html#GstSample"><span class="returnvalue">GstSample</span></a> * gst_app_sink_pull_preroll (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> or NULL when the appsink is stopped or EOS.</td> |
| </tr> |
| </tbody> |
| </table></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="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstSample.html#GstSample"><span class="returnvalue">GstSample</span></a> * gst_app_sink_pull_sample (<em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="http://library.gnome.org/devel/glib/unstable/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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstBuffer.html#GstBuffer"><span class="type">GstBuffer</span></a> or NULL when the appsink is stopped or EOS.</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <hr> |
| <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="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="structfield"><code><a name="GstAppSinkCallbacks.eos"></a>eos</code></em> ()</span></p></td> |
| <td>Called when the end-of-stream has been reached. This callback |
| is called from the steaming thread.</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="structfield"><code><a name="GstAppSinkCallbacks.new-preroll"></a>new_preroll</code></em> ()</span></p></td> |
| <td>Called when a new preroll sample is available. |
| This callback is called from the steaming 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.</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="structfield"><code><a name="GstAppSinkCallbacks.new-sample"></a>new_sample</code></em> ()</span></p></td> |
| <td>Called when a new sample is available. |
| This callback is called from the steaming 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.</td> |
| </tr> |
| </tbody> |
| </table></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><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> *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="http://library.gnome.org/devel/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>, |
| <em class="parameter"><code><a href="http://library.gnome.org/devel/glib/unstable/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> |
| <div class="variablelist"><table border="0" class="variablelist"> |
| <colgroup> |
| <col align="left" valign="top"> |
| <col> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>appsink</code></em> :</span></p></td> |
| <td>a <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base/html/gst-plugins-base-plugins-appsink.html#GstAppSink"><span class="type">GstAppSink</span></a> |
| </td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>callbacks</code></em> :</span></p></td> |
| <td>the callbacks</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>user_data</code></em> :</span></p></td> |
| <td>a user_data argument for the callbacks</td> |
| </tr> |
| <tr> |
| <td><p><span class="term"><em class="parameter"><code>notify</code></em> :</span></p></td> |
| <td>a destroy notify function</td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-base-libs-appsink.see-also"></a><h2>See Also</h2> |
| <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstSample.html#GstSample"><span class="type">GstSample</span></a>, <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-libs/html/GstBaseSink.html"><span class="type">GstBaseSink</span></a>, appsrc |
| </div> |
| </div> |
| <div class="footer"> |
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