The GStreamer framework is used to control the GStreamer graph. It provides the following functionality:
Start/stop video stream inside a graph
Get/set controls
Buffer operations
Get frames-per-second information
There are four states defined in the GStreamer graph: “NULL”, “READY”, “PAUSED”, and “PLAYING”. The “PLAYING” state of a GStreamer graph is used to start the pipeline and the “NULL” state is to stop the pipeline.