How to use a webm with grey Alpha Channel?

[AodhanGorman]

I have a WEBM file with a grey alpha channel that I'm trying to use as a wipe transition for the start of a video, but the alpha channel was rendered as grey, not the black Premiere apparently recognizes. Is there anyway to use this clip with transparency or would I need to find it as a raw file and re-export it with a black alpha channel?

[Joëlle Bh]

I hope i understood what you said ..but if the webm file is high quality you can try to put the ultra key effect on the webm file and remove the grey but this works only if removing the grey doesnt affect the color dramatically of the transition effect that you are trying to do.

try also to change the opacity of the transition to SCREEN  it might work ... you can also try another opacity options it depends on the transition look you want

if nothing of these options work for you ..i want you to show me the transition so i can help you ... post a screenshot or a screen recorded video

[AodhanGorman]

I re-uploaded a video of what I was able to do with Ultra Key to the original post.

Its kinda funky still which is why I'm trying to use the WEBM if possible.

A shareable link to the file is below, hope it helps!

https://drive.google.com/file/d/1juJwZRwwSCWB2IcyuGAoIfJZf5NtVean/view?usp=sharing

[Joost van der Hoeven]

What are you using to import the webm footage? http://www.fnordware.com/WebM/?

[AodhanGorman]

I just dragged and dropped it onto my timeline from a folder on my desktop. Is there a better way to input webm files into Premiere?