Most ambient lighting builds I come across lean on a camera pointed at the screen or a single controller doing everything. This one takes a different route: an HDMI splitter taps the feed on its way up to the TV, and a capture card hands it to a gaming PC running HyperHDR. The maker picked that method after reading it gives the fastest response time, and on a screen this size that seems like a sound bet.
Putting it together took two Adafruit boards. An RP2040 Scorpio drives the strips behind the 86-inch panel, while an ItsyBitsy RP2040 handles a second strip behind the cabinet below. Both boards talk to the PC over USB, and the whole system draws from a standalone 5V 40A supply. The two-controller split was not the first choice; the maker wanted both strips on the Scorpio, but HyperHDR could not support two separate instances without two controllers.
In motion, the strips mirror the on-screen colors and movement in real time and cast localized light onto the wall behind the set. Blackbar detection is kept switched on for TV shows, which I think is a setting plenty of people forget to tune at all.
There are open edges, to be fair. Dark content is tricky at the top bar, since the lack of a true black background makes dark colors hard to separate, and gray or brown scenes come out a dull white. The maker also finds the brightness too dim by day and treats the setup as more of a night-time thing. A threshold setting floated in the discussion has not been found or tried yet, and two nights of tuning ended with a good-enough verdict.