Using ver 4.3.
Q1. I can import video under image plane. My video has an animated object with transparent background (black). I have set Blender background to black but the video appears with a greyish background.
Q2. How to curve an image on a circle like text do?
( You should post in two threads with an according headline for beter results… )
For the first: since you mentioned:
i gues the “video” is imported with imported with the "Images as Planes’ addon and so an image sequence… you also say
…so… is it transparent and you have set the proper values in the import options ? Like: Blend modes (mainly for eevee); use alpha… etc. ?? Also sometimes using the Principled BSDF might be not the best choice or you have to use a mix with a transparent shader.
For the second: (only 350 degree for illustration purposes and the image has to be moved on y for a bit) subdivide and bend :