HDMI signals

HDCP Doctor

The HDfury HDCP conversion engine

HDCP is the reason a perfectly good display sometimes shows nothing at all. HDCP Doctor is the part of the Diva that settles the argument rather than passing it along the chain.

HDCP, High-bandwidth Digital Content Protection, is the copy protection layer that sits under HDMI. A source encrypts the video, the sink decrypts it, and the two agree on a key before anything appears. HDCP 1.4 covers older equipment. HDCP 2.2 arrived with 4K and Ultra HD Blu-ray, and it is not backwards compatible in the way people expect: a 2.2 source will not hand a protected 2.2 stream to a 1.4 sink.

The failure looks like a cable or display fault. You get a black screen, a flashing picture or a protection message, because a device in the chain refused the handshake rather than because a signal was lost. Every device in the path has to satisfy the one behind it, so a single old receiver or splitter can bring the whole run down.

HDCP Doctor is the HDfury name for the block that breaks that dependency. Instead of forwarding protection as it arrives, it terminates the encryption on the input and starts a fresh, separate one on each output at whatever revision that particular sink asked for.

HDCP Doctor on the HDfury Diva

The Diva carries fifteen HDCP 1.4 and 2.2 engines for decryption and encryption, converting HDCP 2.2 to 1.4 and 1.4 to 2.2 within the same unit, in both directions and on all channels at once. Each receiver block decrypts the input first. Each output port then encrypts individually: to 1.4, to 2.2, or not at all if the source was never encrypted. That is what lets an HDCP 2.2 source reach a display that was never HDCP 2.2 compliant.

The one choice you make by hand is in the CONFIG section. HDCP VERSION selects, or forces, the HDCP revision used on the TX1 output port, and the same setting appears in the OLED menu as HDCP, offering AUTO or 1.4. Over RS232 or IP it is set hdcp auto, with 14 as the alternative value. Leave it on AUTO unless a particular sink has to be handed HDCP 1.4.

Where older equipment belongs

HDMI and HDCP 1.x devices go on TX1, the 1080p SDR downscale output. That port exists for equipment predating HDCP 2.2 and 4K: the Diva tone maps and downscales the channel to 1080p SDR and encrypts it to the level that sink expects, so a first generation display or an older receiver locks on instead of reporting an error.

If a sink still goes dark, try ISSUE HOTPLUG in the CONFIG section before anything more drastic. It sends a hotplug event, which performs a soft reset of your setup and makes both ends run the handshake again.

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