HDMI signals
Source and sink
The two ends of every HDMI link
In short
The device that sends an HDMI signal and the device that receives it, the two roles every HDMI connection assigns.
Every HDMI behaviour is negotiated between one source and one sink. The Diva is unusual in being both at the same time: four sink ports facing your players, three source ports facing your displays and your AVR.
The source is the device that sends: a disc player, a console, a set-top box, a computer. The sink is the device that receives: a television, a projector, an AVR input. The roles belong to connectors rather than to boxes, so an AVR is a sink on its HDMI inputs and a source on its output, and anything sitting in the middle of a chain is both, which HDMI calls a repeater.
Traffic runs both ways along the cable. Video, audio and infoframes travel from source to sink. In the other direction the sink raises the hot plug detect line to say it is there, offers its EDID for the source to read, and takes part in the HDCP exchange. The source then picks the best format the EDID permits. That is the point most troubleshooting turns on: the sink describes, the source decides, and no amount of setting the source higher will make it send something the EDID did not advertise.
It follows that a chain is limited by whatever sink the source can see, unless something in the middle rewrites the description. With two displays of different capability connected at once, the honest answer is usually the lowest common denominator, and picture or sound quality is lost for no good reason.
Source and sink on the HDfury Diva
The Diva is a sink on its four HDMI inputs and a source on TX0, TX1 and the dedicated HDMI audio output. It does not hand your display's EDID through untouched. Instead it presents an EDID of its own choosing, using the five modes in the EDID section: COPY TX0 SINK, COPY TX1 SINK, FIXED EDID, CUSTOM and AUTOMIX. In CUSTOM each input can be told a different story, which is worth doing when a games console and a disc player do not need the same one.
The split applies to encryption as well. Each receiver block decrypts its input first, then each output port encrypts on its own to HDCP 1.4, to 2.2, or not at all if the source was never encrypted. That per-port independence is what allows an HDCP 2.2 source to reach a display that was never HDCP 2.2 compliant, instead of going dark with an error.
Working out which end is at fault
The INFO section reports both ends in columns. EDID TX0 and EDID TX1 give the maximum capabilities of whatever sink is connected at that output, which is a claim your display makes rather than a measurement. IN TX0 shows what arrives from the source, VIDEO TX0 what leaves after processing. On the OLED the same comparison is two lines: the first names the sink and the maximum format it says it accepts, the second shows what is actually going out with an arrow for upscaled, downscaled or untouched. If the display says it accepts 4K60 4:4:4 and the outgoing line says less with a right arrow, the limit is the source or the EDID the Diva is presenting.
Related terms
In the manual
The pages of the HDfury Diva manual where this comes up.