UltraHD's Wide Color Gamut via High
Dynamic Range is an HDMI pipeline of competing formats and
specifications. It must be carefully navigated. Lack of
compliance leads to blank, intermittent, noisy, or
downgraded images. Select the TV, video sources,
receiver/preamp, and interconnecting cabling with care.
Natural life-like images
High Dynamic Range + Wide Color Gamut
High Dynamic Range (HDR) expands the difference between
black and the brightest white light. It creates a
grayscale that allows for the simultaneous display of
brighter-highlights and darker shadow detail. HDR
provides a dynamic window for the expansion of color.
Wide Color Gamut (WCG)
extends the range of color via 10-bit and, eventually 12-bit,
color depth. Partnered with HDR, WCG provides more
shades of color. 10-bit WCG expands the color range from
HDTV's 16.7 million colors to over one billion colors.
12-bit WCG color will further expand to over four billion
The partnership of WCG and HDR is
a breakthrough that produces more natural-life-like
dynamic range is the initial step in UHD-WCG-HDR-HDMI
video pipeline. However, HDR is
available in many formats. This is a concern because
the video source HDR format dictates the decode format
required by the final pipeline step, the TV or
projector. The following lists the current leading
HDR 10-bit color combines the SMPTE HDR & Consumer
Technology Association HDMI 2.0a standards. HDR10 is
the current de-facto baseline format for all UltraHD HDR
employs static gamma as opposed to the dynamic metadata
EOTF process used by more advanced formats.
Dolby Vision currently offers 10-bit color with a future
path to 12bit color. (Current TVs are limited
to 10bit color.)
implemented, 12bit color will increase the color palette
from one to four billion colors.
also engages dynamic metadata EOTF frame by frame
Hybrid Log Gamma (HGL)
HGL is a metadata EOTF broadcast
standard format promoted by the BBC and NHK.
It is also backward compatible with older Standard
Dynamic Range (SDR) broadcasts.
HDR10+ upgrades HDR10 to EOTF correction as Dolby Vision
hidden HDR data that allows for a
simultaneous SDR and HDR broadcast.
SL-HDR2 is a HDR10 based format
that adds metadata EOTF.
SL-HDR3 is a HLG based format that
also adds metadata EOTF.
High Definition Multimedia Interface
HDMI is the UltraHD WCG HDR pipeline interconnect that
includes encryption to impede copying.
HDMI Versions 1.4 to 2.1
All connected components and interconnects must meet the
HDMI is a system of
interconnect cable, dedicated termination, plus encryption
The HDMI software, embed in integrated chips, consists of
three types -- source, repeater, and sink.
Source data embeds in BluRay players, media severs, Internet
streaming devices, cable boxes, and satellite receivers.
Repeater data embeds in AV
receivers, plus any form of video switching.
Sink data embeds in televisions
Each HDMI chip rings software
between connected HDMI chips. If a source and
sink HDMI chip connect, then the chips ring and respond to
each other. If a repeater inserts between the source
and sink, then the repeater chip must also respond to the
HDMI source and sink.
Each HDMI chip seeks confirmation from all connected
devices. An incorrect response, negative handshake,
will result in noise, intermittent images, blank or
downgraded screen images.
The following lists the
specifications and video compatibility of HDMI versions 1.4
Each version is compatible with
the previous version.
HDMI 1.4 & 1.4a
- High Definition 1920 x
- 18Gbps bandwidth with audio return and Ethernet channels.
- 1.4a adds 3D support.
'High Speed' cable
Adds Support for:
- UltraHD 3840 x
- 18Gbps @ 60fps
High Speed' cable.
Adds Support for HDR10
'Premium High Speed' cable.
Adds Support for:
- HGL HDR
Up to 32 channels digital audio.
Recommend 'Premium High
- UltraHD @ up to120fps
(enables virtual reality)
UHD-8K @ 60fps
- 48Gbps bandwidth
- Dolby Vision HDR
- 192kHz 24bit audio
E-ARC (enhanced audio
use 'Ultra High Speed' cable.
The Gorilla in the Screen
jury is still out regarding final UltraHD/UHD-8K WCG/HDR
Component and interconnect compatibility is
poised to create installation havoc.
Therefore prepare installations with a 4 part plan.
1. Provide physical paths for upgrading cable.
2. Seek components that provide HDMI upgrades.
Study each component's setup menu for proper implementation.
4. Inform early adopters they may have to replace
key-components sooner than expected.