3.1.1 Abstract Data Model
This section describes a conceptual model of possible data organization that an implementation maintains to participate in this protocol. The described organization is provided to facilitate the explanation of how the protocol behaves. This document does not mandate that implementations adhere to this model as long as their external behavior is consistent with that described in this document.
Extension-info: This variable stores the information related to ASF Extension Systems obtained from the SDP that the client needs in order to parse RTP packets that contain the ASF Payload Extension System extension. For each stream, the variable needs to store the ID of each Extension System and the size of the Extension System data. If the data is of variable size, the variable needs to store this fact. The order in which the Extension Systems will appear in the RTP packet is also significant. The initial state of this variable is that it contains no information.
Playlist-gen-id: This is a boolean variable which is set to True if the RTSP DESCRIBE response contains the X-Playlist-Gen-Id header. The default value of this variable is False.
Ssrc-list: This variable stores mappings between RTP SSRC field values and streams referenced in RTSP SETUP commands. More than one SSRC value can map to the same stream. The initial state of this variable is that it contains no mappings.
State: This variable stores the client's state. Possible values are INIT, READY, and PLAYING. The initial value of this variable is INIT.