Update texture image using TextureShare Plugin

Hello. I’m trying to play a video using the TextureShare plugin in another application. I used the sample code of TextureShare Plugin based on DirectX 12.
So, I’ve succeed to update the driectX’s texture frame by frame but It’s too slow to send DX’s render target to Unreal’s backbuffer. It is updated approximately every 10 frames. How can I update this resource to Unreal and play very smootly?

And, Is there another way to get the texture from the external application not using the DirectX? I just want to play the streaming texture on Unreal.