#10 Allow capability negotiations
Today RTSP lacks the possibility to do any kind of capability/parameter negotiation or at least
choices regarding media parameters.
I would like to see possibilities for this in the future. My initial idea is to make a offer/answer model.
This will require expanding the SETUP request to carry a message body. A message exchange could
work like this.
1. C->S: Describe
2. S->C: Response with media description, SDP or in the future SDP-NG. This description contains
multiple alternatives or in the case SDP-NG a complete description of the choices regarding media
that the client can do.
3. Client selects its desired configuration.
4. C->S: Setup with message body with choosen configuration in SDP/SDP-NG.
5. S->C: Server either accepts or refuses the setup with the given configuration. Refusing should
happend very rarely as server should not offer anything it can provide.
Such solution should try to keep the difference between media parameters and transport
parameters. Transport parameters should be keept in the transport header to simplify processing in
proxies and firewalls. Conclusion: only media related parameters should be negotiated with the
offer/answer mechanism.
To my knowledge the changes required for this is to allow a message body in SETUP requests. Also
rules how and to what it may be used must be specified.
Logged In: YES
user_id=302620
This is in fact a feature request. Changing category for it.
Why is this needed? Announce / record can already can handle this afaik.
Additionally what more than what is indicated in the describe and setup could be required?