basics/bin.cc

A gstreamermm Gst::Bin example.

/*
 * This example presents basic usage of the Gst::Bin class.
 */
#include <gstreamermm.h>

#include <iostream>

int main(int argc, char *argv[])
{
  Gst::init(argc, argv);

  // Create some elements
  Glib::RefPtr<Gst::Element> fakesrc = Gst::ElementFactory::create_element("fakesrc", "source");
  Glib::RefPtr<Gst::Element> fakesink = Gst::ElementFactory::create_element("fakesink", "sink");

  // Create empty bin
  Glib::RefPtr<Gst::Bin> bin = Gst::Bin::create("my-bin");

  // Add elements to a bin
  try
  {
    bin->add(fakesrc)->add(fakesink);
  }
  catch (const std::runtime_error& ex)
  {
    std::cerr << "Exception while adding: " << ex.what() << std::endl;
    return 1;
  }

  // Some of the elements are actually a bins, so we can cast
  // them.
  Glib::RefPtr<Gst::Element> playbin = Gst::ElementFactory::create_element("playbin");
  Glib::RefPtr<Gst::Bin> playbin_bin = playbin_bin.cast_static(playbin);

  if (!playbin_bin)
  {
    std::cerr << "Cannot find playbin element" << std::endl;
    return 1;
  }


  // We can also iterate through the elements in the bin
  Gst::Iterator<Gst::Element> it = playbin_bin->iterate_recurse();
  std::cout << "List of elements in the container: " << std::endl;
  while (it.next())
  {
    std::cout << " * " << it->get_name() << std::endl;
  }

  // We can also connect to signals emitted by bin, e.g. when
  // the element has been removed.
  bin->signal_element_removed().connect(
    [] (const Glib::RefPtr<Gst::Element>& removed_element)
    {
      std::cout << "Element '" << removed_element->get_name()
                << "' has been removed from the bin" << std::endl;
    }
  );

  bin->remove(fakesink);

  std::cout << "returning from application..." << std::endl;

  return 0;
}