Video signal
Chroma subsampling: 4:4:4, 4:2:2, 4:2:0
How much colour detail travels with the picture; 4:4:4 is full colour, 4:2:0 is what discs and streaming use.
What is it?
A video signal is split into brightness (luma, Y) and colour (chroma, Cb/Cr). With 4:4:4 every pixel carries its own colour. 4:2:2 halves colour resolution horizontally, 4:2:0 halves it horizontally and vertically. Because our eyes see brightness far better than colour, 4:2:0 looks nearly identical for films — which is why UHD Blu-ray and all streaming services are 4:2:0. 4:4:4 matters for PC desktops, text and games where fine coloured edges are visible.
Why it matters with the HDfury Vertex²
The HDfury Vertex² passes 4K60 4:4:4 at full 18 Gbps and can convert chroma on the fly: send 4:2:2 12-bit to a projector that dislikes 4:4:4, or 4:2:0 to an HDMI 1.4 device. It also shows the incoming chroma format on the OLED/INFO page — handy to check whether your source really outputs what you set.
How to use it on the Vertex²
Web server → SCALER → Custom scaling → Colour space for TX0/TX1: 'Follow input', 4:4:4, 4:2:2 or 4:2:0 (each in BT.709 or BT.2020). In the EDID tab an 'YCbCr remove' style flag can tell a source to send RGB only. For LLDV (Dolby Vision on HDR10 displays) the signal is always 12-bit 4:2:2.
Related terms
- Colour depth: 8, 10, 12, 16-bit (deep colour) — How many brightness steps each colour channel has; 10-bit or more avoids banding in HDR.
- 18 Gbps / 600 MHz bandwidth — The maximum data rate of HDMI 2.0 — the Vertex² passes it through untouched.
- Colour space & primaries: BT.709, BT.2020, DCI-P3 — How wide the palette of colours is: BT.709 for HD, DCI-P3 for cinema, BT.2020 for UHD/HDR.
- LLDV (Low-Latency Dolby Vision) — Dolby Vision tone-mapped by the player and sent as 12-bit 4:2:2 — usable on any HDR10 display via the Vertex².
