HDMI tunneling is a feature that lets users preview their content on a Dolby Vision enabled TV. HDMI tunneling enables the iCMU within the color corrector to output video and Dolby Vision metadata signaling to a Dolby Vision TV over an HDMI interface. Because the signal contains the Dolby Vision metadata associated with the content in question, the TV will automatically switch into a Dolby Vision picture mode (that is performing real time display mapping), allowing for a visual quality control check of the content in a manner that mirrors a typical consumer experience. For a list of systems that support HDMI tunneling, refer to the article Dolby Vision Compatible Color Grading & Packaging Systems.

 

This article will cover:

• Recommended Dolby Vision TVs for HDMI Tunneling
• HDMI Tunneling Best Practices
• How to enable HDMI Tunneling in DaVinci Resolve, FilmLight Baselight, and Colorfront Transkoder

Because viewing content via HDMI tunneling is using dynamic display mapping on TVs (that all have their own unique processing behaviors and image quality capabilities), this feature should only be used as a quality control mechanism, not for making color grading or mastering decisions (as the image is not being viewed in it’s true reference state). 

 

Recommended Dolby Vision TVs

For the best results with HDMI tunneling, the following Dolby Vision TVs are recommended:

• LG C2, C3, C4, C5 and G2, G3, G4, G5 series

• Sony A95K, A95L and BRAVIA 8, 9 series

• Panasonic LZ2000, MZ2000, Z95A series

 

HDMI Tunneling Best Practices

The following practices are recommended when utilizing HDMI tunneling for the most optimal viewing experience:

• Allow for a proper break in period for any TV before use in a color critical environment. Dolby recommends at least 100 hours of usage before using the given display for HDMI tunneling.

• Be mindful of what Dolby Vision picture mode is active. Typically, the bright or 'home' modes are the default selection out of the box. 

  • For LG panels, use ‘Dolby Vision Cinema’ for reference mode

  • For Sony and Panasonic panels, use ‘Dolby Vision Dark’ for reference mode

• Confirm that the TV is in Dolby Vision mode. The TV will briefly show a Dolby Vision logo on the screen once the HDMI source is connected and the video is playing. Refer to corresponding TV manuals on how to verify and change picture profiles.

• Always calibrate any TV before use in a color critical environment. For HDMI tunneling purposes, ensure the Dolby Vision picture mode that will be utilized is calibrated before viewing.

  • Dolby Vision calibration options are available from Portrait Displays, refer to their resource center for step-by-step guides

  • For more information on calibration principles and best practices, refer to our dedicated article Display Color Calibration

• Complete any trim passes on the reference/mastering display, do not make creative decisions by viewing images on the TV alone.

 

DaVinci Resolve Setup

1. Set up a Dolby Vision project
2. In the Dolby Vision settings, ensure that Enable Dolby Vision HDMI Tunneling and Enable L5 metadata on HDMI are checked

3. In preferences, navigate to Video and Audio I/O and select the Decklink 8K Pro

4. In the Video Monitoring menu set SDI to 4:4:4 12 bit and enable HDR metadata over HDMI

5. Disable Tone Mapping preview in the Dolby Vision color page (HDMI Tunneling will not work if this is enabled)

Note: HDMI Tunneling with DaVinci Resolve is only supported by the DeckLink 8K Pro G2 card

FilmLight Baselight Setup

1. Set up a Dolby Vision project
2. Navigate to 'Setups' under the 'Baselight' menu

3. Open the edit menu for the project setup and change the Primary Output signal to 'Dolby Vision - HDMI Output Only'

4. A warning should now be present in the Dolby Vision trim layer that HDMI Tunneling is enabled and adjusting trims is not recommended

Note: Refer to the Baselight user guide Section 4, Dolby Vision, Setting up your video output, HDMI tunneling for more information

 

Colorfront Transkoder Setup

1. Set up a Dolby Vision project
2. Navigate to Settings and select the Video tab
3. Select 'On' for 'HDMI Output Enabled'

 

4. Select 'On' for 'Dolby Vision HDMI Tunneling'
5. Dolby Vision crop refers to L5 metadata being sent if letterboxing or masks are applied on the timeline
6. Set HDMI Output to 'RGB Full' or 'Auto'
   1. Transkoder will have 'Auto' be RGB Full when HDMI tunneling is enabled
7. Select 'Color Depth on HDMI' to '12 bit' or 'Auto'
   1. Transkoder will have 'Auto' be 12 bit when HDMI Tunneling is enabled

Note: Refer to the Transkoder user guide Dolby Vision HDMI tunneling for information