Summary

I am trying to create a TV production pipeline using the NDI In/Out TOP.

What I am trying to do is:

  1. Input live video in Log format to TouchDesigner using a Blackmagic capture card.
  2. Send it to Unreal Engine using NDI.
  3. Convert the received NDI signal from Unreal Engine from Log to RGB.
  4. Perform real-time compositing in Unreal Engine.
  5. Output the result from a Blackmagic capture card.

That is the flow of the system.

Issue

While building the system, I noticed that the colors were changing between the input video from the camera and the output video from Unreal Engine.

At first, I thought the colors were changing every time they passed through the Blackmagic device, but as I narrowed down the scope, I found that the color change at the NDI In/Out TOP stage was the biggest.

Specifically, there may be a mismatch in color space conversion between RGB and YUV between the NDI Out TOP and NDI In TOP.

In the system I am currently developing, I am trying to address this issue by creating a custom NDI Output TOP using a CPlusPlus TOP. However, the performance is not very good, so I hope that the issues with TouchDesigner's NDI In/Out TOP will be fixed in the future.

I have summarized the verification details in case it can be helpful for problem-solving. The following is the information: