ExtMapAttribute Class

https://tools.ietf.org/html/rfc5285#section-5 Stream or media-level attribute used to indicate the presence of RTP Header Extensions, and the mapping of local identifiers used in the header extension to a larger namespace. A usable mapping MUST use IDs in the valid range, and each ID in this range MUST be used only once for each media (or only once if the mappings are session level). Mappings that do not conform to these rules MAY be presented, for instance, during offer/answer negotiation as described in the next section, but remapping to conformant values is necessary before they can be applied. Each extension is named by a URI. Each local identifier potentially used in the stream is mapped to a string using an attribute of the form: a=extmap:VALUE["/"DIRECTION] URI EXTENSIONATTRIBUTES Where URI is a URI, as above, VALUE is the local identifier (ID) of this extension and is an integer in the valid range inclusive (0 is reserved for padding in both forms, and 15 is reserved in the one-byte header form), and direction is one of "sendonly", "recvonly", "sendrecv", or "inactive" (without the quotes). Example: a=extmap:1 http://example.com/082005/ext.htm#ttime a=extmap:2/sendrecv http://example.com/082005/ext.htm#xmeta short