GStreamer provides a clean interface to:
The application programmer who wants to build a media pipeline. The programmer can use an extensive set of powerful tools to create media pipelines without writing a single line of code. Performing complex media manipulations becomes very easy.
The plugin programmer. Plugin programmers are provided a clean and simple API to create self-contained plugins. An extensive debugging and tracing mechanism has been integrated. GStreamer also comes with an extensive set of real-life plugins that serve as examples too.