Many have professed confusion about HDR formats, with a belief that there are large number of different formats that provide compatibility and capability issues. However it is not as confused as it may seem once the fundamentals of HDR technology are understood and clarified.
News coming from CES this week is particularly full of these references, with discussion about HDR10+, Dolby Vision and Advanced HDR (from Technicolor). They are seen as new and incompatible approaches to the display of HDR and this is seen as some as a fundamental war of video formats, reopening the wounds of the pre-standardisation PQ and HLG discussions. However these are not video formats as such. These are display rendering solutions based on the processing, creation and delivery of additional metadata alongside the video format. Dolby Vision, HDR10+ and Advanced HDR are based upon the SCTE 2094 series of standards for Dynamic Metadata. It is an important difference, particularly with regard to video distribution for an operator or broadcaster.
In reality there are two core HDR video formats for distribution, PQ and HLG (alongside SDR). Each has its better application depending on a variety of technical opinions and market situations, but regardless whether delivering video using PQ and/or HLG, it will be receivable and usable by almost all HDR TVs that have been produced since CES2016. PQ (or Perceptual Quantizer) based video provides a pure HDR display-only video solution, whilst HLG (Hybrid Log Gamma) provides a HDR video solution with an SDR ‘backwards compatibility’ that provides a more universal solution for mixed SDR/HDR UHD displays (except the very oldest early adopter displays that only support BT709 colour space).
It is also important to note that many TVs make use of HDR enhanced processing without the use of metadata, in ways that are proprietary to the manufacturer of the TV and in many respects Dolby Vision and HDR10+ are in the same realm as those solutions, although each offers what the manufacturer of the TV sees as being their consumer product advantage. Dolby Vision and HDR10+ offer a more multi-vendor solution approach to that processing than the proprietary solutions.
I hope this clarifies HDR so when you see the confusion or Format War articles/comments coming from CES. This is just one aspect of HDR video delivery and if you are investigating the deployment of HDR platforms during 2018 do get in touch to discuss where we can help further from architecture to delivery.
Fairmile West is a Consulting company focused on working in the Consumer Device and Video arena. We work with clients on technology strategy and product delivery through key practices in Consumer Devices and Video Services. If you are interested in learning more about what we do, please do get in touch via our website – Contact us. You can also keep track with what interests us in the industry by following our Link blog at TV Tech News, and you can specifically follow news on Ultra HD via the following link – Ultra HD News.