For Netflix productions, metadata can be delivered one of 2 ways:
- Separate XML Sidecar metadata file
- Embedded in the Video MXF of an IMF Package - can be viewed by two methods:
- using clip inspector in supported software (i.e. Colorfront TransKoder)
- extracting the metadata via Dolby CM Offline
Level 1 (Image character analysis) - required for ALL shots
- Default color mapping will be applied based on Dolby’s analysis values.
Level 2 <TID 1> (SDR Trim Pass values) - not required for every shot
- Will be included only if creative talent decides additional color adjustments need to be made on a scene-by-scene basis.
Common QC Issues
Issue: Some software versions are unable to register the metadata for use in creating an SDR pass or read metadata embedded in an MXF in IMPs for display.
Example: Current Colorfront versions can not utilize DoVi Metadata or view metadata in its clip inspector on IMPs generated by some versions of Clipster)
Best Practice: To examine the Dolby Vision metadata, extract it via Dolby Metafier as an XML and open the extracted file with a text editor of choice. Validate .xml through Dolby Metafier.
Image Character values:
Issue: The metadata contains <ImageCharacter> values of 0,0,0 for any shots that are not black frames. This indicates the shot has not been properly analyzed when creating the HDR metadata. These shots should appear the same in both HDR and SDR on most devices, as no color mapping is being applied. Although, some devices will translate the 0,0,0 values as black frames instead of displaying any picture at all.
Example: LG G6 monitors, Vizio M Series monitors, TCL monitors
Best Practice: This can manually be confirmed within the metadata itself, either by inspecting the shot or searching through the extracted DoVi metadata for any 0,0,0 values. As all shots must be analyzed, this always requires a fix.
Color mapping/ timing error:
Issue: Durations in metadata do not align with hard cuts in the video, causing color/ luminance mistimes (shifts) midshot in the SDR video.
Best Practice: Extract the metadata and validate for overlapping and missing durations using Dolby Metafier prior to QC. Also, use clip inspector in supported software to check for metadata value changes that do not align with cuts. This always requires a fix.
Canvas and Image Aspect Ratio settings:
Issue: If either or both of these values are set incorrectly, content mapping will not be applied
to the image correctly. If positive lift values are also utilized in the trim pass, this can manifest
as shifting / elevated black levels in the mattes for letterboxed content, visible in the SDR output
derived from the Dolby Vision metadata. If the active image area is larger than what is
represented in the metadata, it will be visible as “translucent” bars in the image where the
content mapping is not being applied in the SDR output.
Best Practice: During the Dolby Vision analysis to generate the metadata, ensure that your
<CanvasAspectRatio> is set to the full resolution of the frame (represented as a non-negative,
- For full 4K deliveries (4096x2160) - this should always be 1.89630
- For UHD (3840x2160) or HD (1920x1080) deliveries - this should always be 1.77778
Ensure that your <ImageAspectRatio> is set to the A/R of the active image within the frame,
minus any mattes (represented as a non-negative, decimal number). If the aspect ratio is a
continuous decimal number, a maximum of 5 decimal places of precision is required to account
for one-line discrepancies. If the aspect ratio is a whole number integer or a finite decimal
number, it can be represented with the amount of decimal places to match its value from a
single decimal place up to 5 decimal places of precision.
- For a show delivering 2:1 - this can be represented as 2.0 or 2.00 or 2.00000
- For a show delivering full frame - this should match the Canvas Aspect Ratio
If either or both of these settings do not match the video track as delivered, it will always require
Additional notes: If there are multiple creatively intended active image aspect ratios,
<ImageAspectRatio> should be set to the largest active image aspect ratio that is utilized.
Then, include L5 dynamic aspect ratio metadata values for the shots that deviate from this
global Image Aspect Ratio.
- Filmlight Baselight currently does not support the addition of L5 dynamic aspect ratio
metadata. For titles finishing in Baselight, the workaround is to set the global
<ImageAspectRatio> to the largest active image aspect ratio that is utilized. Then, avoid
any positive lift values in the trim pass to ensure shifting/ elevated black levels do not
occur in the mattes in the SDR output during those shots that deviate from the global
For QC partners: Please make sure you are always verifying both the Canvas and Image
Aspect Ratio settings in the Dolby Vision metadata are accurate to the full resolution and active
image aspect ratio of the video track. If you are unable to verify the metadata, in the case of
Cast QC where only the HDR/ SDR encoded streams are served, be mindful of visual errors
that would indicate there is a problem with these settings. If there is shifting/ elevated black
levels in the mattes that are visible only in the SDR stream, that would indicate a potential issue
with the Canvas or Image Aspect Ratio settings. Also, if there are “translucent” bars in the
image top/ bottom or left/ right that are visible only in the SDR stream, where the HDR color is
essentially being passed through unmapped, that would also indicate a potential issue with