Over the last few months, Netflix rolled out a new version of HDR to optimize video quality on all devices, including TVs, mobile devices, and tablets.
The format, called HDR-VMAF (Video Multimethod Assessment Fusion), uses a machine learning technology developed by Netflix called Dynamically Optimized encoding. It was designed to help Netflix offer a more consistent video experience regardless of their device.
Netflix unveiled the details of HDR-VMAF on Thursday in a Medium post published under the Netflix Tech Blog name.
As Netflix expands its collection of 4K titles and moves to even more devices, optimizing HDR across all of a consumer’s devices ensures that all subscribers get a consistently strong video quality that improves the viewing experience for subscribers. Content will look clearer and have more defined details., as explained in the Netflix Tech Blog.
HDR-VMAF also measures HDR quality through signals instead of display characteristics to better control streaming quality across devices to become “format-agnostic,” meaning video playback is consistent no matter which type of device someone uses. Videos will play at their peak luminance with balanced black levels and a broad color range.
Netflix launched HDR videos in 2016 and began working on VMAF in 2020, but in-person testing was postponed due to the pandemic. Instead, Netflix worked with Dolby Laboratories to test its 4K-HDR content with high-end OLED panels in precisely calibrated conditions in participants’ homes. Testing for HDR-DO (Dynamically Optimized) took place during the last half of 2021, and by June of this year, Netflix’s entire HDR catalog was optimized with VMAF.
By optimizing all HDR to VMAF, Netflix said it can reduce its storage footprint, internet data usage, and “most importantly, improve the video quality for our members.” Audiences should notice 40% less buffering when streaming HDR content, as well as higher video quality and lower play delays. When watching content on multiple devices, users should see less variation in video quality and less internet data usage, especially on mobile devices and tablets.
While Netflix has developed HDR-VMAF for its internal needs, the company said it is committed to supporting the open-source community. It is working to ensure the technology is stable, versatile, and easy to use before an official release.