<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.13"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>gstreamermm: basics/dynamic_pads.cc</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="doxygen.css" rel="stylesheet" type="text/css" /> <link href="doxygen-extra.css" rel="stylesheet" type="text/css"/> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td id="projectalign" style="padding-left: 0.5em;"> <div id="projectname">gstreamermm  <span id="projectnumber">1.10.0</span> </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.13 --> <script type="text/javascript" src="menudata.js"></script> <script type="text/javascript" src="menu.js"></script> <script type="text/javascript"> $(function() { initMenu('',false,false,'search.php','Search'); }); </script> <div id="main-nav"></div> </div><!-- top --> <div class="header"> <div class="headertitle"> <div class="title">basics/dynamic_pads.cc</div> </div> </div><!--header--> <div class="contents"> <p>A gstreamermm dynamic <a class="el" href="classGst_1_1Pad.html" title="A class that represents objects contained by elements that allows links to other elements. ">Gst::Pad</a> example.</p> <div class="fragment"><div class="line"><span class="comment">/*</span></div><div class="line"><span class="comment"> * This example presents basic usage of dynamics Gst::Pad objects.</span></div><div class="line"><span class="comment"> */</span></div><div class="line"><span class="preprocessor">#include <gstreamermm.h></span></div><div class="line"><span class="preprocessor">#include <glibmm/main.h></span></div><div class="line"></div><div class="line"><span class="preprocessor">#include <<a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01265.html">iostream</a>></span></div><div class="line"></div><div class="line"><span class="keywordtype">int</span> main(<span class="keywordtype">int</span> argc, <span class="keywordtype">char</span> *argv[])</div><div class="line">{</div><div class="line"> <a name="a0"></a><a class="code" href="namespaceGst.html#a4368f0336db20f7dae336c97ebce0ef1">Gst::init</a>(argc, argv);</div><div class="line"></div><div class="line"> Glib::RefPtr<Glib::MainLoop> main_loop = Glib::MainLoop::create();</div><div class="line"></div><div class="line"> <span class="comment">// Create pipeline</span></div><div class="line"> Glib::RefPtr<Gst::Pipeline> pipeline = <a name="a1"></a><a class="code" href="classGst_1_1Pipeline.html#a128afc567b461f52e180b37d76dc1c4d">Gst::Pipeline::create</a>(<span class="stringliteral">"my_pipeline"</span>);</div><div class="line"></div><div class="line"> <span class="comment">// Create elements</span></div><div class="line"> Glib::RefPtr<Gst::Element> source = <a name="a2"></a><a class="code" href="classGst_1_1ElementFactory.html#a6a85a2a3c4f69383cad2686d381e10e9">Gst::ElementFactory::create_element</a>(<span class="stringliteral">"videotestsrc"</span>, <span class="stringliteral">"source"</span>),</div><div class="line"> decodebin = <a class="code" href="classGst_1_1ElementFactory.html#a6a85a2a3c4f69383cad2686d381e10e9">Gst::ElementFactory::create_element</a>(<span class="stringliteral">"decodebin"</span>, <span class="stringliteral">"decoder"</span>),</div><div class="line"> sink = <a class="code" href="classGst_1_1ElementFactory.html#a6a85a2a3c4f69383cad2686d381e10e9">Gst::ElementFactory::create_element</a>(<span class="stringliteral">"autovideosink"</span>, <span class="stringliteral">"videosink"</span>);</div><div class="line"></div><div class="line"> <span class="comment">// Add elements to a pipeline</span></div><div class="line"> <span class="keywordflow">try</span></div><div class="line"> {</div><div class="line"> pipeline->add(source)->add(decodebin)->add(sink);</div><div class="line"> }</div><div class="line"> <span class="keywordflow">catch</span> (<span class="keyword">const</span> <a name="_a3"></a><a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00912.html">std::runtime_error</a>& ex)</div><div class="line"> {</div><div class="line"> <a name="a4"></a>std::cerr << <span class="stringliteral">"Exception while adding: "</span> << ex.what() << <a name="a5"></a><a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"> <span class="keywordflow">return</span> 1;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="comment">// Link elements</span></div><div class="line"> <span class="keywordflow">try</span></div><div class="line"> {</div><div class="line"> <span class="comment">// We can't link decodebin with sink, because decodebin</span></div><div class="line"> <span class="comment">// doesn't have any src pad on start up.</span></div><div class="line"> source->link(decodebin);</div><div class="line"> }</div><div class="line"> <span class="keywordflow">catch</span> (<span class="keyword">const</span> <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00912.html">std::runtime_error</a>& ex)</div><div class="line"> {</div><div class="line"> std::cerr << <span class="stringliteral">"Exception while linking: "</span> << ex.what() << <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"> }</div><div class="line"></div><div class="line"> <span class="comment">// Handle messages posted on bus</span></div><div class="line"> pipeline->get_bus()->add_watch([main_loop] (<span class="keyword">const</span> Glib::RefPtr<Gst::Bus>&,</div><div class="line"> <span class="keyword">const</span> Glib::RefPtr<Gst::Message>& message) {</div><div class="line"> <span class="keywordflow">switch</span> (message->get_message_type())</div><div class="line"> {</div><div class="line"> <span class="keywordflow">case</span> <a name="a6"></a><a class="code" href="namespaceGst.html#ga704e8de3c3f9698d3c3ca15d61190a86abeac2aa69521997263a705f48468cc1e">Gst::MESSAGE_EOS</a>:</div><div class="line"> <span class="keywordflow">case</span> <a name="a7"></a><a class="code" href="namespaceGst.html#ga704e8de3c3f9698d3c3ca15d61190a86a758493cee50de74b68fa2fe29ba4bad9">Gst::MESSAGE_ERROR</a>:</div><div class="line"> main_loop->quit();</div><div class="line"> <span class="keywordflow">break</span>;</div><div class="line"> <span class="keywordflow">default</span>:</div><div class="line"> <span class="keywordflow">break</span>;</div><div class="line"> }</div><div class="line"> <span class="keywordflow">return</span> <span class="keyword">true</span>;</div><div class="line"> });</div><div class="line"></div><div class="line"> <span class="comment">// Listen for newly created pads</span></div><div class="line"> decodebin->signal_pad_added().connect([decodebin, sink] (<span class="keyword">const</span> Glib::RefPtr<Gst::Pad>& pad) {</div><div class="line"> <a name="a8"></a>std::cout << <span class="stringliteral">"New pad added to "</span> << decodebin->get_name() << <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"> std::cout << <span class="stringliteral">"Pad name: "</span> << pad->get_name() << <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"></div><div class="line"> <a class="code" href="group__gstreamermmEnums.html#gadcf0c9fa45112e2b7b6c549de4b28b05">Gst::PadLinkReturn</a> ret = pad->link(sink->get_static_pad(<span class="stringliteral">"sink"</span>));</div><div class="line"></div><div class="line"> <span class="keywordflow">if</span> (ret != <a name="a9"></a><a class="code" href="namespaceGst.html#gadcf0c9fa45112e2b7b6c549de4b28b05a892e0cc3606cad7972322a896b093f64">Gst::PAD_LINK_OK</a>)</div><div class="line"> {</div><div class="line"> std::cout << <span class="stringliteral">"Cannot link pads. Error: "</span> << ret << <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"> }</div><div class="line"> <span class="keywordflow">else</span></div><div class="line"> {</div><div class="line"> std::cout << <span class="stringliteral">"Pads linked correctly!"</span> << <a class="codeRef" href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a01616.html#a8b3758bb8f17c440c7963363f42f69f3">std::endl</a>;</div><div class="line"> }</div><div class="line"> });</div><div class="line"></div><div class="line"> <span class="comment">// Start the pipeline</span></div><div class="line"> pipeline->set_state(<a name="a10"></a><a class="code" href="namespaceGst.html#gabb043e1d41659fd842f10949f91e7a7fa396ac09161e15f45f8dc574a91bfef2b">Gst::STATE_PLAYING</a>);</div><div class="line"> main_loop->run();</div><div class="line"> pipeline->set_state(<a name="a11"></a><a class="code" href="namespaceGst.html#gabb043e1d41659fd842f10949f91e7a7fa07cf1506b030700024ecf1654c3796c2">Gst::STATE_NULL</a>);</div><div class="line"></div><div class="line"> <span class="keywordflow">return</span> 0;</div><div class="line">}</div></div><!-- fragment --> </div><!-- contents --> <!-- start footer part --> <hr class="footer"/><address class="footer"><small> Generated on Sat Oct 21 2017 12:59:00 for gstreamermm by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/> </a> 1.8.13 </small></address> </body> </html>