A Bin is a container element. You can add elements to a bin. Since a bin is an element itself, it can also be added to another bin. Bins allow you to combine connected elements into one logical element. You do not deal with the individual elements anymore but with just one element, the bin. We will see that this is extremely powerfull when you are going to construct complex pipelines since it allows you to break up the pipeline in smaller chunks. The bin will also manage the elements contained in it. It will figure out how the data will flow in the bin and generate an optimal plan for that data flow.

There are two standard bins available to the GStreamer programmer: A pipeline (GstPipeline). Which is a generic container you will use most of the time. A thread (GstThread). All the elements in the thread bin will run in a separate thread. You will haver to use this bin if you carfully have to synchronize audio and video for example. You will learn more about threads in.. The application programmer can create custom bins packed with elements to perform a specific task. This allow you to write an MPEG audio decoder with just the follwing lines of code: // create the mp3player element GstElement *mp3player = gst_elementfactory_make("mp3player","mp3player"); // set the source mp3 audio file gtk_object_set(GTK_OBJECT(mp3player), "location", "helloworld.mp3", NULL); // tell the mp3player to prepare itself gst_element_set_state(GST_ELEMENT(mp3player),GST_STATE_READY); // start playback gst_element_set_state(GST_ELEMENT(mp3player),GST_STATE_PLAYING); ... // pause playback gst_element_set_state(GST_ELEMENT(mp3player),GST_STATE_PAUSED); ... // stop gst_element_set_state(GST_ELEMENT(mp3player),GST_STATE_NULL);