Ed’s AV Handbook
Saving the world from poor fidelity
HDR Ultra-HDTV (3/17)
Part 3 HDR Format War?
An HDR UltraHDTV must support the source HDR format. If not, the image may be downgraded to standard dynamic range at less than Ultra-HD resolution or worse — a blank screen. The issue is a standard format does not yet exist.
Several current TVs support more than one HDR format. To date, HDR10 and Dolby Vision are the most prominent. However a Technicolor/Philips joint venture is becoming an alternative; As is the BBC/NHK Hybrid Log-Gamma (HLG) format. The following is a list of the competing formats being considered.
HDR10 (10-bit color) is a combination of the SMPTE HDR standard and Consumer Technology Association HDMI 2.0a spec. It is currently the baseline format. An enhanced HDR12 is also in the works that support Dynamic HDR as the Dolby Vision and HGL formats.
Warning: Beware of Entry-level Ultra-HDTVs advertised as “HDR-enabled or compatible’. They may recognize HDR10 content and produce a picture. But they DO NOT provide HDR performance.
12 Bit Dolby Vision
Dolby is a 12bit color format. In comparison to 10bit formats — the 2 extra bits increases the color palate from one billion to four billion colors. Dolby is also a dynamic format that continuously optimizes night and daylight images on a ‘dynamic’ frame-by-frame basis.
In addition Dolby Vision is compatible with the HDMI 2.0 and 2.0a standards (HDR10 requires 2.0a). Dolby is also backward compatible with HDR10 sets. In my mind backward to HDR10 says it all.
Phillips Technicolor Format
Phillips/Technicolor is a Dynamic HDR format that requires the HDMI 2.0a standard. It has been reported that it may be more compatible with the library of standard-dynamic-range HDTV video broadcast and Ethernet streaming. (I’m not sure what that will actually mean on the TV screen.) The jury is out.
Hybrid Log-Gamma (HLG)
HLG is being promoted by the BBC & NHK as a broadcast standard that employs a Dynamic frame-by-frame EOTF process based on the display’s actual peak luma value. HLG requires HDMI 2.0b. This format may be the long shot winner in this possible war.
Is it a war?
The lack of a standard may produce a format war. But don’t Panic – yet. There are still other issues to be concerned about such as every AV pro’s favorite subject – HDMI.
That’s Next in part 4.