Dolby Vision Technical Webinar | Summer 2023

Just a few highlights from Dolby’s webinar

• Changes to Dolby Vision Licensing
• New Guidance on Setting the Mastering Display
• New Recommendations Regarding Full & Video Levels

Dolby Vision License

In the Legacy Program, components (Trims License, eCMU License and Professional Tools) were bundled together for $2,500 for a period of 12 months. The new program splits the bundle up and the license is perpetual. A Trims License will cost $1,000. Those who purchased a 1-year license on or after June 15, 2022 are eligible for a free upgrade to a perpetual license.

New Guidance on Setting the Mastering Display

The new mastering display guidelines streamline Rec.2020 based workflows and optimize color mapping.

Full & Video Levels

Video monitoring via iCMU can be Full or Legal range. 

“When outputting from the color corrector in Full range, it is necessary to ensure that your reference display input is also set to Full range and this recommendation to output in Full range stems from the fact that the eCMU that resides on an external server can only handle SDI signals in the SDI Full range format. So [the key takeaway] here is if you are using an eCMU, you have to output an SDI Full range from the color corrector and you have to set up the input of your HDR as well as the SDR display for mapping purposes to reflect this SDI Full range choice. So, when you are opting for a legal range output, basically all that happens is that the quantization is now performed to an integer value ranging from 64 to 940 to be in compliance with the Legal or the Video range specifications for 10-bit video signals. So, if you’d like to output in Video or Legal range, you must set your reference display setup accordingly. So, make sure that you’re also setting the video input of your HDR as well as SDR display to Video mode. And the thing to remember is, this is absolutely fine for iCMU workflows only; you can use Legal range video output for iCMU purposes but not for eCMU purposes. The whole Full and Legal topic is not only relevant when it comes to monitoring, but also when it comes to rendering, especially when exporting video to ProRes files. We must consider that there are certain types of codecs that expect either RGB values, which are usually Full range, and then there are other codec families that expect Y’CbCr values that are typically Legal range. So, a codec that would expect Full range data, for instance, would be TIFF, JPEG 2000, DPX, Cineon, and others. A good example of a codec that expects Legal range data is ProRes. Baselight serves as a really good example here, as when rendering to ProRes, Baselight automatically applies a scaling to Legal range. Resolve applies the same when you’re rendering to ProRes if you have set the data levels to Auto. So our recommendation is, when you’re exporting to ProRes, just leave the respective setting for scaling and data levels at their at their default values. Baselight also brings up a warning when you are rendering ProRes files other than in Legal range. Resolve does not bring up this warning, so again, just leave the color corrector at its default state (Auto) when you’re exporting ProRes. Now that we know how software may handle ProRes on export, let’s see how they handle ProRes on import. Again, we are using Baselight here as an example, as it has a nice view called the Color Space Journey that outlines all the transformations that are happening throughout the whole color pipeline. What we can see here is that immediately on import, Baselight expects that the ProRes file is encoded in Legal range, so it will automatically scale from Legal to Full (or from Legal to floating point precision). The same happens in DaVinci Resolve, there’s just not this this nice view, but if you go to clip attributes and play with the data levels, if they are set to Auto, you will see that the imported ProRes matches the outputted ProRes exactly. The same would apply for setting this to Video range, but if you would set it manually to Full, then you would see that there is a shift in the video file.”