Hi there,
I have read the project description, short but not easy to have the ready solution for it.
The tricky part is to display caller's live video on called party's phone, without answering it.
This depends also on the end phone, which I believe will not send video until it gets 200 OK, or at least 183 Session Progress (with SDP body). The latter is what I just think, and need to verify/test.
Since there may be other hacks (i.e. OpenSIPS/Kamailio to play man-in-the-middle against SIP flow), it's best to discuss to what extent you want the solution to be. For example, the call can be answered properly (200 OK), but the video stream from called party will be suppressed; this approach has one caveat: caller will see call duration counting, which indicates the call has been answered...)
I guess this is similar to a doorbell video system.
Feel free to let me know more details, and I'll see whether we can have a workaround. SIP specs, at this point, can allow displaying a still image in the INVITE, however I don't see it applied in this case.
Price bid is just a place holder, and does not reflect the real deal.
Thanks and regards,
Bao