UltraHD/UHD8K's Wide Color Gamut
via High Dynamic Range is an HDMI pipeline of competing formats
and specifications. It must be carefully navigated.
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 more 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 the
UltraHD/UHD-8K HDR-WCG-HDMI 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 formats.
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 correction 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 gamma
Dolby Vision IQ video
metadata, via a TV light sensor, adjusts the picture to
the room's ambient lighting.
embedded IQ dynamic metadata also adjusts the TV's picture
settings in real-time.
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.
Samsung HDR10+ upgrades HDR10 to EOTF gamma correction
as Dolby Vision and HLG.
Technicolor HDR-2-U Advanced
hidden HDR data that allows for a
simultaneous SDR HDR broadcast.
SL-HDR2 is a HDR10 based format
that adds metadata EOTF gamma correction.
SL-HDR3 is a HLG based format that
also adds metadata EOTF gamma correction.
High Definition Multimedia Interface
HDMI is the UltraHD/UHD-8K HDR-WCG interconnect
pipeline 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 an
interconnect cable, dedicated termination, plus HDMI &
HDCP encryption software.
The 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 any form
of video switching -- AV receivers, AV preamp/processors, AV
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 of 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.
- Sourced-Based Tone
SBTM optimizes/maps TV
display HDR luminance and color with the HDMI
2.1a source data .
use 'Ultra High Speed' cable.
The Gorilla in the Screen
jury is still out regarding final UltraHD/UHD-8K
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 meet UltraHD/UHD-8K HDMI HDR
specs or provide for upgrades.
Study each component's setup menu for proper implementation.
4. Inform early adopters they may have to replace
key-components sooner than expected.