Outlook 2020: The ongoing evolution of HDR
Bryce Button
Issue: November/December 2019

Outlook 2020: The ongoing evolution of HDR

HDR quickly evolved from production trend to industry standard in 2019. From live broadcast and event production to film, TV and episodic post production, it’s become woven into the entire production chain. A continued deluge of HDR content from OTT outfits like Apple, Disney, Netflix, Hulu and Amazon is helping to drive on-going consumer demand as they have set expectations for more dynamic imagery. With HDR adoption growing from production through post, technology and workflows are rapidly progressing; HDR standards, though often misunderstood, are improving the flow of HDR content throughout the production pipeline. Emerging developments like 12G-SDI and HDR monitoring and analysis tools are also changing the game, simplifying HDR pipelines while setting content up to pass through quality control quickly and priming HDR for even wider adoption in 2020.  

Demystifying HDR Standards

There’s a general misconception that HDR is overly complex. In reality, one only needs to be able to understand two main formats, Perceptual Quantizer (PQ) and Hybrid Log Gamma (HLG), and they’re fairly straightforward. PQ sits at the base of a range of different metadata approaches, but the bottom line is that the color space and means of transmission are fundamentally the same. For professionals working in P3, the dominant color space for delivery, it’s simply a matter of building on that base and finding tools that assist with necessary metadata work. HLG, on the other hand, does not require metadata; SDR and HDR are accommodated within the same video signal. Looking to the new year, growing adoption of SMPTE standards will provide a means for transporting HDR metadata across SDI, making SDI HDR pipelines more efficient and predictable. 

Technological Advancements Fueling HDR Adoption

In the last few years, emerging transport and display technologies like 12G-SDI and HMDI have paved the way for simpler transmission of high resolution HDR signals to high resolution displays. 12G-SDI has become a larger part of the HDR conversation, as it supports more efficient cabling in the transport of higher raster HDR content and provides enhanced bandwidth. Rather than grouping four 3G-SDI cables to get a 4K HDR signal transported from device to display, a single 12G-SDI cable can achieve the same task. Evolving HDMI standards have also simplified HDR video signal transit to higher raster affordable HDMI displays. Combined, these two technologies are streamlining HDR approaches for higher raster content. 

HDR Monitoring & Analysis 

Based on recent industry discussions, it’s clear that there is an incredible demand for HDR-capable tools to interoperate more seamlessly throughout the entire production chain. This includes the ability to monitor HDR in post, whether editing, grading or performing some other task. Most available technology is not fine-tuned in terms of scope, waveform and nit level readings, so we have seen some concerns in HDR grading work. This is why adopting tools that allow the objective measurement of where materials are sitting within post, including the dynamic range and color space positioning for file materials, is a smart idea. It’s especially vital in the offline stage, because it draws attention to any composition lighting issues from the original footage that could pose a problem in the HDR conversion process. Having this insight in the offline process leads to greater efficiency in terms of shot selection and reduces the risk of using shots that will not work as well in the HDR space as they did in SDR. 

A production that harnesses monitoring and analysis technology is far more likely to get finished productions past QC with minimal kickbacks from the engineering team. Having these tools in post can save time, making it easy to quickly set white balances and nit levels and save color choices within an expanded color environment, so that the focus can be on making creative decisions within the HDR environment and not technical considerations. These tools are quickly evolving and improving, making it simpler to manage metadata in SDI to HDMI conversion for display. AJA, for instance, develops a wide range of tools that offer metadata settings and capabilities through free, complementary software for its I/O devices and Mini-Converters. Additionally, AJA offers HDR monitoring and analysis tools like the HDR Image Analyzer, which our customers report helps nearly 100 percent of their work pass QC for delivery. In the near future, we’re also looking to streamline how our converters transmit Dolby Vision HDR materials coming across SDI to HDMI in realtime. 

Overall, HDR has progressed rapidly and 2019 marked a year of evolution for HDR capabilities in nonlinear editing tools and color grading packages, but we’ve still got a way to go. That said, development will take off quite quickly in 2020. While several NLE and color grading packages are still in the early stages of HDR workflow implementations, manufacturers are working fast and furiously to add new features that support the demands of professionals in the field. Moving into the new year, both production and post tools will continue to advance what’s possible with HDR and reach a point of maturation with the HDR feature sets they have to offer. Given AJA’s background in audio and video I/O, you can bet that we will be a part of this effort, working to simplify how professionals feed signals from workstations to displays or for realtime HDR monitoring.

Bryce Button is the director of product marketing at AJA Video Systems (https://www.aja.com) in Grass Valley, CA.