The Reader-Writer Architecture uses a component called a Source Reader to provide the media data and a Sink Writer component to consume it. The Source Reader does contain a type of internal pipeline but this is not accessible to the application. A Source Reader is not a Media Source and a Sink Writer is not a Media Sink and neither can be directly included in a Pipeline or managed by a Media Session. In general, the media data flows from the Source Reader to the Sink Writer by the actions of the application. The application will either take the packets of media data (called Media Samples) from the Source Reader and give them directly them to the Sink Writer or it will set up a callback function on the Source Reader which performs the same operation. In effect, as it manages the data transport, the application itself performs a similar role to that of the Media Session in a Pipeline Architecture application. Since the MF application manages the transmission of the Media Samples between the Source Reader and Sink Writer it will always have access to the raw media data. The Source Reader and Sink Writer components do have a limited ability to automatically load Media Transforms to assist with the conversion of the format of the media data, however, this is done internally and the application has little control over it.