The vcu_gst_app is a command line multi-threaded Linux application that uses the vcu_gst_lib interface similar to vcu_qt. The difference is to manually feed the input configuration and run the pipeline each time, whereas with vcu_qt, the application has to launch only once.
The command line application requires an input configuration file (input.cfg) to be provided in plain text. Refer to Input Configuration File for the file format and description.