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| <a href="#gst-plugins-bad-libs-GstAggregator.description" class="shortcut">Description</a></span> |
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| <div class="refentry"> |
| <a name="gst-plugins-bad-libs-GstAggregator"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="gst-plugins-bad-libs-GstAggregator.top_of_page"></a>GstAggregator</span></h2> |
| <p>GstAggregator — manages a set of pads with the purpose of |
| aggregating their buffers.</p> |
| </td> |
| <td class="gallery_image" valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.functions"></a><h2>Functions</h2> |
| <div class="informaltable"><table width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="functions_return"> |
| <col class="functions_name"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="function_type"> |
| <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a> |
| </td> |
| <td class="function_name"> |
| <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#gst-aggregator-finish-buffer" title="gst_aggregator_finish_buffer ()">gst_aggregator_finish_buffer</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-bad-libs-GstAggregator.html#gst-aggregator-set-src-caps" title="gst_aggregator_set_src_caps ()">gst_aggregator_set_src_caps</a> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| <tr> |
| <td class="function_type"> |
| <a href="https://developer.gnome.org/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> |
| </td> |
| <td class="function_name"> |
| <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#gst-aggregator-iterate-sinkpads" title="gst_aggregator_iterate_sinkpads ()">gst_aggregator_iterate_sinkpads</a> <span class="c_punctuation">()</span> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.other"></a><h2>Types and Values</h2> |
| <div class="informaltable"><table width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="name"> |
| <col class="description"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="datatype_keyword">struct</td> |
| <td class="function_name"><a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator">GstAggregator</a></td> |
| </tr> |
| <tr> |
| <td class="datatype_keyword">struct</td> |
| <td class="function_name"><a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregatorClass" title="struct GstAggregatorClass">GstAggregatorClass</a></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.description"></a><h2>Description</h2> |
| <p>Manages a set of pads with the purpose of aggregating their buffers. |
| Control is given to the subclass when all pads have data.</p> |
| <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> |
| <li class="listitem"><p> |
| Base class for mixers and muxers. Implementers should at least implement |
| the <code class="function">aggregate()</code> vmethod. |
| </p></li> |
| <li class="listitem"><p> |
| When data is queued on all pads, tha aggregate vmethod is called. |
| </p></li> |
| <li class="listitem"><p> |
| One can peek at the data on any given GstAggregatorPad with the |
| <a class="link" href="gst-plugins-bad-libs-GstAggregatorPad.html#gst-aggregator-pad-get-buffer" title="gst_aggregator_pad_get_buffer ()"><code class="function">gst_aggregator_pad_get_buffer()</code></a> method, and take ownership of it |
| with the <a class="link" href="gst-plugins-bad-libs-GstAggregatorPad.html#gst-aggregator-pad-steal-buffer" title="gst_aggregator_pad_steal_buffer ()"><code class="function">gst_aggregator_pad_steal_buffer()</code></a> method. When a buffer |
| has been taken with <code class="function">steal_buffer()</code>, a new buffer can be queued |
| on that pad. |
| </p></li> |
| <li class="listitem"><p> |
| If the subclass wishes to push a buffer downstream in its aggregate |
| implementation, it should do so through the |
| <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#gst-aggregator-finish-buffer" title="gst_aggregator_finish_buffer ()"><code class="function">gst_aggregator_finish_buffer()</code></a> method. This method will take care |
| of sending and ordering mandatory events such as stream start, caps |
| and segment. |
| </p></li> |
| <li class="listitem"><p> |
| Same goes for EOS events, which should not be pushed directly by the |
| subclass, it should instead return GST_FLOW_EOS in its aggregate |
| implementation. |
| </p></li> |
| </ul></div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.functions_details"></a><h2>Functions</h2> |
| <div class="refsect2"> |
| <a name="gst-aggregator-finish-buffer"></a><h3>gst_aggregator_finish_buffer ()</h3> |
| <pre class="programlisting"><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html#GstFlowReturn"><span class="returnvalue">GstFlowReturn</span></a> |
| gst_aggregator_finish_buffer (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a> *agg</code></em>, |
| <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBuffer.html"><span class="type">GstBuffer</span></a> *buffer</code></em>);</pre> |
| <p>This method will take care of sending mandatory events before pushing |
| the provided buffer.</p> |
| <div class="refsect3"> |
| <a name="id-1.2.7.2.6.2.5"></a><h4>Parameters</h4> |
| <div class="informaltable"><table 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>self</p></td> |
| <td class="parameter_description"><p>The <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a></p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>buffer</p></td> |
| <td class="parameter_description"><p>the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstBuffer.html"><span class="type">GstBuffer</span></a> to push.</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-aggregator-set-src-caps"></a><h3>gst_aggregator_set_src_caps ()</h3> |
| <pre class="programlisting"><span class="returnvalue">void</span> |
| gst_aggregator_set_src_caps (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a> *agg</code></em>, |
| <em class="parameter"><code><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstCaps.html"><span class="type">GstCaps</span></a> *caps</code></em>);</pre> |
| <p>Sets the caps to be used on the src pad.</p> |
| <div class="refsect3"> |
| <a name="id-1.2.7.2.6.3.5"></a><h4>Parameters</h4> |
| <div class="informaltable"><table 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>self</p></td> |
| <td class="parameter_description"><p>The <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a></p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>caps</p></td> |
| <td class="parameter_description"><p>The <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstCaps.html"><span class="type">GstCaps</span></a> to set later on the src pad.</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="gst-aggregator-iterate-sinkpads"></a><h3>gst_aggregator_iterate_sinkpads ()</h3> |
| <pre class="programlisting"><a href="https://developer.gnome.org/glib/unstable/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a> |
| gst_aggregator_iterate_sinkpads (<em class="parameter"><code><a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a> *self</code></em>, |
| <em class="parameter"><code><span class="type">GstAggregatorPadForeachFunc</span> func</code></em>, |
| <em class="parameter"><code><a href="https://developer.gnome.org/glib/unstable/glib-Basic-Types.html#gpointer"><span class="type">gpointer</span></a> user_data</code></em>);</pre> |
| <p>Iterate the sinkpads of aggregator to call a function on them.</p> |
| <p>This method guarantees that <em class="parameter"><code>func</code></em> |
| will be called only once for each |
| sink pad.</p> |
| <div class="refsect3"> |
| <a name="id-1.2.7.2.6.4.6"></a><h4>Parameters</h4> |
| <div class="informaltable"><table 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>self</p></td> |
| <td class="parameter_description"><p>The <a class="link" href="gst-plugins-bad-libs-GstAggregator.html#GstAggregator" title="struct GstAggregator"><span class="type">GstAggregator</span></a></p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>func</p></td> |
| <td class="parameter_description"><p>The function to call.</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="parameter_name"><p>user_data</p></td> |
| <td class="parameter_description"><p>The data to pass to <em class="parameter"><code>func</code></em> |
| .</p></td> |
| <td class="parameter_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.other_details"></a><h2>Types and Values</h2> |
| <div class="refsect2"> |
| <a name="GstAggregator"></a><h3>struct GstAggregator</h3> |
| <pre class="programlisting">struct GstAggregator { |
| GstElement parent; |
| |
| GstPad * srcpad; |
| |
| GstSegment segment; |
| }; |
| </pre> |
| <p>Collectpads object.</p> |
| <div class="refsect3"> |
| <a name="id-1.2.7.2.7.2.5"></a><h4>Members</h4> |
| <div class="informaltable"><table 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="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html"><span class="type">GstElement</span></a> <em class="structfield"><code><a name="GstAggregator.parent"></a>parent</code></em>;</p></td> |
| <td> </td> |
| <td> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstPad.html"><span class="type">GstPad</span></a> *<em class="structfield"><code><a name="GstAggregator.srcpad"></a>srcpad</code></em>;</p></td> |
| <td> </td> |
| <td> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstSegment.html"><span class="type">GstSegment</span></a> <em class="structfield"><code><a name="GstAggregator.segment"></a>segment</code></em>;</p></td> |
| <td> </td> |
| <td> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GstAggregatorClass"></a><h3>struct GstAggregatorClass</h3> |
| <pre class="programlisting">struct GstAggregatorClass { |
| GstElementClass parent_class; |
| |
| GType sinkpads_type; |
| |
| GstFlowReturn (*flush) (GstAggregator * aggregator); |
| |
| GstFlowReturn (*clip) (GstAggregator * agg, |
| GstAggregatorPad * bpad, |
| GstBuffer * buf, |
| GstBuffer ** outbuf); |
| |
| /* sinkpads virtual methods */ |
| gboolean (*sink_event) (GstAggregator * aggregate, |
| GstAggregatorPad * bpad, |
| GstEvent * event); |
| |
| gboolean (*sink_query) (GstAggregator * aggregate, |
| GstAggregatorPad * bpad, |
| GstQuery * query); |
| |
| /* srcpad virtual methods */ |
| gboolean (*src_event) (GstAggregator * aggregate, |
| GstEvent * event); |
| |
| gboolean (*src_query) (GstAggregator * aggregate, |
| GstQuery * query); |
| |
| gboolean (*src_activate) (GstAggregator * aggregator, |
| GstPadMode mode, |
| gboolean active); |
| |
| GstFlowReturn (*aggregate) (GstAggregator * aggregator); |
| |
| gboolean (*stop) (GstAggregator * aggregator); |
| |
| gboolean (*start) (GstAggregator * aggregator); |
| }; |
| </pre> |
| <p>The aggregator base class will handle in a thread-safe way all manners of |
| concurrent flushes, seeks, pad additions and removals, leaving to the |
| subclass the responsibility of clipping buffers, and aggregating buffers in |
| the way the implementor sees fit.</p> |
| <p>It will also take care of event ordering (stream-start, segment, eos).</p> |
| <p>Basically, a basic implementation will override <em class="parameter"><code>aggregate</code></em> |
| , and call |
| _finish_buffer from inside that function.</p> |
| <div class="refsect3"> |
| <a name="id-1.2.7.2.7.3.7"></a><h4>Members</h4> |
| <div class="informaltable"><table 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="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/GstElement.html#GstElementClass"><span class="type">GstElementClass</span></a> <em class="structfield"><code><a name="GstAggregatorClass.parent-class"></a>parent_class</code></em>;</p></td> |
| <td> </td> |
| <td> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><a href="https://developer.gnome.org/gobject/unstable/gobject-Type-Information.html#GType"><span class="type">GType</span></a> <em class="structfield"><code><a name="GstAggregatorClass.sinkpads-type"></a>sinkpads_type</code></em>;</p></td> |
| <td class="struct_member_description"><p>Optional. |
| The type of the pads that should be created when |
| GstElement.request_new_pad is called.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.flush"></a>flush</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called after a succesful flushing seek, once all the flush |
| stops have been received. Flush pad-specific data in |
| <a class="link" href="gst-plugins-bad-libs-GstAggregatorPad.html#GstAggregatorPad" title="struct GstAggregatorPad"><span class="type">GstAggregatorPad</span></a>->flush.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.clip"></a>clip</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when a buffer is received on a sink pad, the task |
| of clipping it and translating it to the current segment |
| falls on the subclass.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.sink-event"></a>sink_event</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when an event is received on a sink pad, the subclass |
| should always chain up.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.sink-query"></a>sink_query</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when a query is received on a sink pad, the subclass |
| should always chain up.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.src-event"></a>src_event</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when an event is received on the src pad, the subclass |
| should always chain up.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.src-query"></a>src_query</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when a query is received on the src pad, the subclass |
| should always chain up.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.src-activate"></a>src_activate</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Called when the src pad is activated, it will start/stop its |
| pad task right after that call.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.aggregate"></a>aggregate</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Mandatory. |
| Called when buffers are queued on all sinkpads. Classes |
| should iterate the GstElement->sinkpads and peek or steal |
| buffers from the <a href="http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-bad-libs/html/gst-plugins-bad-libs-GstAggregatorPad.html#GstAggregatorPad"><span class="type">GstAggregatorPads</span></a>. If the subclass returns |
| GST_FLOW_EOS, sending of the eos event will be taken care |
| of. Once / if a buffer has been constructed from the |
| aggregated buffers, the subclass should call _finish_buffer.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.stop"></a>stop</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Should be linked up first. Called when the |
| element goes from PAUSED to READY. The subclass should free |
| all resources and reset its state.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| <tr> |
| <td class="struct_member_name"><p><em class="structfield"><code><a name="GstAggregatorClass.start"></a>start</code></em> ()</p></td> |
| <td class="struct_member_description"><p>Optional. |
| Should be linked up first. Called when the element goes from |
| READY to PAUSED. The subclass should get ready to process |
| aggregated buffers.</p></td> |
| <td class="struct_member_annotations"> </td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a name="gst-plugins-bad-libs-GstAggregator.see-also"></a><h2>See Also</h2> |
| <p>gstcollectpads for historical reasons.</p> |
| </div> |
| </div> |
| <div class="footer"> |
| <hr> |
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