HDR Insights Series Article 4 : Dolby Vision

differentiating their service offerings. This requires that the content suppliers are equipped to
deliver good quality and compliant HDR content. Moreover, having the ability to verify quality
before delivery becomes more important.
Many of these OTT services support both the HDR-10 and Dolby Vision flavors of HDR.
However, more and more Netflix HDR titles are now based on Dolby Vision. Dolby Vision is a
new and complex technology, and therefore checking the content for correctness and
compliance is not always easy. Delivering non-compliant HDR content can affect your business
and therefore using a QC tool to assist in HDR QC can go a long way in maintaining a good
standing with these OTT services.
Here are some of the important aspects to verify for HDR-10 and Dolby Vision:
1. HDR metadata presence
HDR-10: Static metadata must be coded with the correct parameter values.
Dolby Vision: Static metadata must be present once and dynamic metadata must be present for
every shot in the content.
2. HDR metadata correctness. There are a number of issues that content providers need to check
for correctness in the metadata:
Only one mastering display should be referenced in metadata.
Correct mastering display properties – RGB primaries, white point and Luminance range.
MaxFALL and MaxCLL values.
All target displays must have unique IDs.
Correct algorithm version. Dolby supports two versions:
Metadata Version 2.0.5 XML for CMv2.9
Metadata Version 4.0.2 XML for CMv4
No frame gaps. All the shots, as well as frames, must be tightly aligned within the timeline and
there should not be any gap between frames and/or shots
No overlapping shots. The timeline must be accurately cut into individual shots; and analysis to
generate L1 metadata should be performed on a per-shot basis. If the timeline is not accurately
cut into shots, there will be issues with luminance consistency and may lead to flashing and
flickering artifacts during playback.
No negative duration for shots. Shot duration, as coded in “Duration” field, must not be negative
Single trim for a particular target display. There should be one and only one trim for a target
display.
Level 1 metadata must be present for all the shots.
Valid Canvas and Image aspect ratio. Cross check the canvas and image aspect ratio with the
baseband level verification of the actual content.
3. Validation of video essence properties. Essential properties such as Color matrix, Color
primaries, Transfer characteristics, bit depth etc. must be correctly coded.
Netflix requires the Dolby Vision metadata to be embedded in the video stream for the content
delivered to them. Reviewing the embedded meta-data in video stream can be tedious and
therefore an easy way to extract & review the entire metadata may be needed and
advantageous.