HDR Ultra-HDTV Part 4

Ed’s AV Handbook
Saving the world from poor fidelity
HDR Ultra-HDTV

Part 4  The High Definition Multimedia Interface
HDMI can be the bane of an AV professional’s daily work.  Blank screens, intermittent video, and noisy images caused by inconsistent manufacturing, changing specs, and long cable lengths are all too common.  This blog won’t change that.  But it may add some insight that leads to possible solutions.

The ‘High Definition Multimedia Interface’ is a system (19 conductor interconnecting cable, dedicated termination, and microprocessing IC’s with software) that primarily prevents unauthorized copying.  The HDMI IC’s are installed in the source component, the display, and in any component in the system path (receiver/preamp/switcher).

The source HDMI IC pings the next HDMI IC.  That chip simultaneously responds with a return ‘handshake message’ AND pings the next chip (if any).  Each chip waits for the ‘handshake’ response.  Any incorrect responses results in a blank screen, intermittent picture, or noisy picture.  Solutions can include;
– Unplug and reinsert cable.
– Replace the cable. But not necessarily a more expensive cable – just another cable.
– Experiment by replacing electronic components.  Even if the component works in another          system.  Some combinations simply don’t like each other.
– Set up all system components in-house to confirm performance before driving to an                    installation.

HDMI has evolved thru many versions.  Each is backward compatible which permits the previous evolution of video and audio to pass.

HDMI 1.4 & 1.4a (4,096 x 2,160 @ up to 24fps)
Version 1.4 supports HDTV plus the audio return and Ethernet channels.
Version 1.4a supports 3D.
– Recommend ‘High Speed’ (high bandwidth) cable.

HDMI 2.0 (3840 x 2160p @ 60fps)
Version 2.0 supports Ultra High Definition 18Gbps bandwidth @ 60fps.
It also provides for dual screen video streams. (sort of picture in picture)
– Recommend ‘Premium High Speed’ cable.

HDMI 2.0a
Version 2.0a supports High Dynmaic Range formats.
– Recommend ‘Premium High Speed’ cable.

HDMI 2.0b
Version 2.0b supports EOTF Dynamic HDR formats.
2.0b also provides up to 32 channels of multi-dimensional digital audio.
– Recommend ‘Premium High Speed cable.

HDMI 2.1 supports 48Gbps bandwidth, 8K video resolution @ 60Hz or UltraHD @ 120Hz.
Support for 120 frames per second enables Virtual and Augmented Reality.  2.1 also supports Hi-Resolution audio, object based surround sound, and E-ARC (audio return channel).
– Install 48Gbps bandwidth cable.

The first HDMI 2.1 product won’t be released until 2018.  Although 2.1 supports 48Gbps bandwidth, Internet providers are still trying to deal with 25Gbps.  So, don’t reach for your wallet yet.  But do prep your installations for cable replacement.  Their is is lot to be confirmed.

 

That concludes part 4.  Next part 5  More HDMI Tips.

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