I looked into it a bit further and it seems the ATSC stream packets already contain built-in checksums! The interesting bit is that all the sub-channels are actually inter-mixed in one stream. So if you’re tuned to 13-1, your TV is reading and ignoring 13-2, 13-3 etc.

Unfortunately, I don’t know of any stream-correcting p2p network. I think it would start with a relatively open source tuner card. I think the tuner software is typically closed source, but it would be doing the work of reading the radio stream of a frequency and sending out an mpeg stream.