This article briefly covers the following FAQs on using the Dolby Vision workflow in color grading and mastering tools:

 

• What display should I use for creating content in Dolby Vision?
• Which color grading and mastering tools support Dolby Vision?
• Should I use Dolby Vision version CMv2.9 or CMv4.0?
• How can I test the Dolby Vision workflow?
• Where can I get Dolby Vision open source content?
• Which source formats are suited best for grading in Dolby Vision?
• Why are the L1 and L3 values in the user interface different from the L1 and L3 values stored in the Dolby Vision metadata when Dolby Vision CMv4.0 is used?
• Why are the <ColorSpace> and <SignalRange> tags set to “RGB” and “Full” by default, when exporting a Dolby Vision XML from a timeline of my color corrector?
• Do I need to set the <ColorSpace> and <SignalRange> parameter in the Dolby Vision metadata for QuickTime ProRes deliveries manually?
• How to manage animated blanking/letterboxing (L5)?

 
 

What display should I use for creating content in Dolby Vision?

There are many suitable displays available from a range of manufacturers, including many professional reference display manufacturers. 
Dolby does not recommend or certify any particular professional displays or publish a list of preferred HDR displays.  If you require specific guidance before selecting a particular display, this should be discussed with the clients or studios you will be creating content for and/or your usual equipment supplier. 
There are also other organizations and sources that define specifications for HDR displays, for example the EBU has published their User Requirements for Video Monitors in Television Production (Tech 3320) which includes specifications for different grades of HDR displays.   
 
Read more in our HDR monitor considerations article.


 

Which color grading and mastering tools support Dolby Vision analysis and content mapping?

Dolby Vision is supported in many postproduction software applications. See this Knowledge Article for more info.


 

Should I use Dolby Vision version CMv2.9 or CMv4.0?

It is recommended to use Dolby Vision 4.0 for all projects. Dolby Vision 4.0 has more functionality and in general yields better results in comparison to Dolby Vision 2.9 and it is backward compatible. If your delivery requires CMv.2.9 metadata you can easily export it out of a Dolby Vision 4.0 project. For more information about the differences between Dolby Vision CMv.2.9 and CMv.4.0, please refer to this Knowledge Article .

 

How can I test the Dolby Vision workflow?

You can test the Dolby Vision workflow with any tool that supports Dolby Vision content creation. These tools offer integrated Dolby Vision capabilities at no additional charge from Dolby. 

If you want to test the Dolby Vision workflow using the The Dolby Vision Trim Controls, you can sign up for our Dolby Vision Certified Professional program and receive a temporary evaluation license on request.


 

Where can I get Dolby Vision open source content?

Encouraging the industry to learn more about the benefits of Dolby Vision and Dolby Atmos Netflix made many open source assets available. 
Check this article on how to access Dolby Vision and Dolby Atmos open source content.

Which source formats are suited best for grading in Dolby Vision?

When content is going to be color graded, it is recommended to use source material that best retains the native color gamut and original dynamic range of the content at the time of its origination in order to create high quality Dolby Vision content. 

Where content will be directly edited and then aired with just some minor color corrections or even without a color grading process, capturing in a format that matches to the color gamut and dynamic range of the delivery requirements can enable a simpler workflow. 

As Dolby Vision can deliver higher dynamic range with a wider color gamut, and at a greater bit depth than SDR delivery systems, ensuring these wider ranges are captured at the onset, is important to creating the best Dolby Vision masters.
Learn more about recommended source formats in this article .

 

 

Why are the L1 and L3 values in the user interface different from the L1 and L3 values stored in the Dolby Vision metadata when Dolby Vision CMv4.0 is used?

When using Dolby Vision version 4.0, L1 is stored in the Dolby Vision Metadata as backwards compatible CMv2.9 values plus L3 offset values that restore the original CM4.0 L1 and L3 values. Color correctors display the original measured values from L1 and L3 as CMv4.0 L1 and mid tone offset on the user interface.


 

Why are the <ColorSpace> and <SignalRange> tags set to “RGB” and “Full” by default, when exporting a Dolby Vision XML from a timeline of my color corrector?

When exporting Dolby Vision metadata from a Dolby Vision timeline, the Metadata is not associated with a specific video file or image sequence, but the timeline / project it’s a part of. The color corrector doesn’t have a precognition about the video or image format you’ll be exporting and associating the XML with down the line, so applications default to the highest quality image export settings, setting the XML value of <ColorSpace> to “RGB” and <SignalRange> to “Full”, so that if you export a Dolby Vision TIFF master in the working space, you’ve got the XML formatted correctly.
 

Do I need to set the <ColorSpace> and <SignalRange> parameter in the Dolby Vision metadata for QuickTime ProRes deliveries manually?

When source images are ProRes encoded, Dolby Vision Professional Tools and downstream decoders ignore the <ColorSpace> and <SignalRange> field in the metadata (XML) and use the data delivered by Apple’s ProRes library instead of managing signal range values themselves. Therefore, Dolby Vision metadata associated with ProRes deliveries can be marked as either "Full/Computer" or "Legal/Video" without impacting mapping or downstream encoding.
 

 How to manage animated blanking/letterboxing (L5)?

Dolby Vision Metadata carries letterboxing/blanking information that defines the active image area for Dolby Vision mapping during playback. This information is represented as L5 metadata in the Dolby Vision XML. L5 must be defined globally (for the entire timeline) for all Dolby Vision metadata (XMLs), but they may also be assigned per shot if certain shots or sequences have an aspect ratio/blanking that is different from the global value. 

In some cases there may be a creative requirement to animate the transition from one aspect ratio/blanking value to another, within the span of a shot or sequence of shots. Although Dolby Vision metadata supports frame by frame L5 for such scenarios, there is currently no implementation in our partner solutions (color correction and mastering systems) to automatically create the corresponding Dolby Vision metadata in such cases. Hence, if a user creates an animation for the aspect ratio/blanking across a shot or sequence, the system will not translate that into the required frame by frame L5 metadata automatically.

In such situations, we recommend setting the L5 to the largest framing in that sequence and treating the animated letterbox/blanking as a graphic within that frame. For example, if the blanking changes from 1.78 to 2.35 for one or more shots in a sequence, set the L5 value to 1.78 for all these shots and let the animation take place within this framing. We recommend NOT using positive lift above +0.025 in such cases, to avoid potential lifting of the letterbox/blanking area of the image.

This recommendation also applies to shots with asymmetric blanking, like pillar boxes.