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Ed's AV Handbook
Batting Practice for the AV Professional
and primer for the novice

Chapter 4  Page 9

Video Reproduction
The UltraHD HDR HDMI Pipeline

Natural life-like images
HDR TV Screen

UltraHDTV, 8K-UHD plus High Dynamic Range is a pipeline of competing formats and specifications that must be carefully navigated.  Lack of compliance leads to blank, intermittent, noisy, or downgraded images.  Select the television, video sources, and interconnecting cabling with care

High Dynamic Range

High Dynamic Range (HDR) expands the difference between black and the brightest white light.  A grayscale that allows for the simultaneous display of brighter-highlights and darker shadow detail, with an expanded range of color.  HDR is a breakthrough that produces natural life-like images. 

HDR Formats 

High dynamic range is the initial step in this video pipeline.  However, HDR is available in many formats.  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 televisions. 
HDR10 employs static gamma as opposed to the dynamic metadata EOTF process used by more advanced formats.

Dolby Vision
Dolby Vision offers up to 12bit color.   (Although current TVs are limited to 10bit color.)
When implemented, 12bit color will increase the color palette from one to four billion colors. 
Dolby also engages dynamic metadata EOTF frame by frame correction. 

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 and HLG. 

SL-HDR1 includes 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
Versions 1.2 to 2.1

This is the UltraHD HDR pipeline interconnect with encryption that prevents copying. 
All connected components and interconnects must meet the HDMI specs. 


HDMI is a system of interconnect cable, dedicated termination, plus encryption software. 
The HDMI software, embed in integrated chips, consists of three types -- source, repeater, and sink.

Source Data
Source data embeds in BluRay players, media severs, Internet streaming devices, cable boxes, and satellite receivers.

Repeater Data
Repeater data embeds in AV receivers, plus any form of video switching.

Sink Data
Sink data embeds in televisions and projectors.

Each HDMI chip rings software in the next HDMI chip.   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.

The following lists the compatibility specifications of HDMI versions 1.4 through 2.1.
Each version is compatible with the previous version.

HDMI 1.4 & 1.4a
- High Definition 1920 x 1080
- 18Gbps bandwidth with audio return and Ethernet channels.
- 1.4a adds 3D support.
Recommend 'High Speed' cable

HDMI 2.0
Adds Support for:
- UltraHD 3840 x 2160p resolution.
- 18Gbps @ 60fps
Recommend 'Premium High Speed' cable.

HDMI 2.0a

Adds Support for HDR10
Recommend 'Premium High Speed' cable.

HDMI 2.0b
Adds Support for:
- Up to 32 channels digital audio.
Recommend 'Premium High Speed' cable.

HDMI 2.1
Adds Support for: 
- UltraHD @ up to120fps
(120fps enables augmented reality)
- UHD-8K @ 60fps
- 48Gbps bandwidth
- HDR10+
- HDR 12bit Dolby Vision
- 192kHz 24bit audio (lossless DTS)
- E-ARC (enhanced audio return channel)
Must use 'Ultra High Speed' cable.

The Gorilla in the Screen 

The jury is still out regarding final UltraHD/UHD-8K HDR implementation. 
Component and interconnect compatibility is
poised to create custom installation havoc. 
Therefore prepare installations with a three part plan.

1. Provide physical paths for upgrading cable.
2. Seek components that provide HDMI upgrades.
3. Inform early adopters they may have to replace key components.

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Ed's AV Handbook   
Copyright 2007 Txu1-598-288 Revised 2021

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