Remove black background for transparent video

[ali-raza-flutter]

Hi,
I am trying to play a video with transparent background in .webm format. The video runs fine but the player will add a black background which defeats the purpose of a transparent video.
Is there a way to remove that from the background?

[arcticfox1919]

@ali-raza-flutter
Not sure what the black background refers to? Can you provide a screenshot?