Are there any way that you can play out a webm-file with alpha in CasparCG?
With the play-command CasparCG plays out the file but it doesnt recognize the alpha-channel.
As a test example-file I have used Geerts start_1080.webm from his HTML-template tutorial, that is a file that I know has alpha when it is inside a HTML-template.
I do it a lot, but as you say in HTML. I have tried to do it just as an mediafile with amcp and get the same result as you. I have files that I know for sure is webm with alpha if need to try. (I made them my self).
I use webM with alpha frequently in Mello for example.
But the problem is that the file is done in AE with with VP8 and in the settings the “Include Alpha channel” ticked.
and the result in a HTML-template
The most strange thing was that when I tried to play out the webm-file with the HTML producer it didnt use the alpha channel either.
Render straight (for best result) alpha from ex. Aftereffects and than i usally use ffmpeg to conform to webm
ffmpeg -i Blaffa_1.mov -c:v libvpx-vp9 -b:v 6M -pix_fmt yuva420p -auto-alt-ref 0 Blaffa_1.webm
ffmpeg -i Blaffa_1.mov -c:v libvpx-vp9 -b:v 6M -pix_fmt yuva420p -auto-alt-ref 0 -codec:a libvorbis -qscale:a 8 Blaffa_1.webm
There is also a webm codec online, floating around somewhere, that some of the girls/guys here use.
You may have to tweek the ffmpeg to get your desired result.
I think the problem is somehow related to this: