Combine tv-out from raspberry with normal tv

[vladb]

At home i have both analog and digital stations from the local cable company.
I would like to open a webpage on raspberry and keep it always open, take the video out signal and mix it with the signal from the cable company without overlapping with existing channels.
Is this possible? Do i need to buy one or more devices to allow for this?

Thank you for your time!

[unclejed613]

are you talking about sending out your pi's video (and i would imagine audio as well) on an RF signal into the cable system? if so, you used to be able to back-feed a TV channel through cable systems. the CATV distribution amps had a directional coupler, where everything above 42Mhz went in the "forward" (i.e. from the head-end to the subscribers) direction, and everything below 42Mhz was in the "reverse" (from the subscribers to the head-end) direction. this facilitated feeds from subscribers to the "public access" channels. of course, these feeds had to be scheduled, and the subscriber needed to rent special equipment to provide public access content. the content would be recorded at the head-end, and sent out on one of the "forward" channels designated as a public access channel on a fixed schedule at a later time. since the changeover to digital TV, i don't think this arrangement exists any more since all that extra space below 42Mhz is likely used for DOCSIS (internet)