SDI output using BlackMagic

We are developing a project that output the camera view with fill and key to SDI using “Blackmagic Design Media Player”.

However, we are facing 2 problems:

  1. Output multi view using multi camera
    We are successful to output 1 view using “Capture Active Scene Viewport”.
    However, we want to output multiple view with multiple camera in our project.
    In blueprint, “Capture Active Scene Viewport” can only output the active view, so we also tried “Capture Texture Render Target 2D”, but this produced the second problem.

  2. Color in Render Target is not same as viewport
    Here is the different:
    Actual color in viewport:

Color in Render Target:

Why would these color different occur?

How can we solve the above problems?

Thank you

sorry for the late answer but this is what you need to have full control over video compositing in unreal