Transparent blur in template

Hi, I’m trying to create a template that has a background with Gaussian blur rather than a color or a texture.

Here is a quick example of what I’m trying to achieve and

I understand that to get proper blur my template need to get the color data from the layer below which would be the output of my vision mixer. Has anybody done anything like this before? I could really use some advice as to a setup that could pull this off. I have access to multiple Decklink recorders so I can feed my Caspar machine with the output from the vision mixer.

Thanks for any advice!

This is not easy, as, as you already mentioned, you need to process the background video. The second problem is, that Caspar can not blur video. Dependant on you vision mixer you could use a second key output, that is used to key a blur effect of the mixer. So you would at least be able to control the area of the blur.

This is a typical effect used in post production and not in live TV.

I think you can do it in an ffmpeg filter.

But that would mean having to pass the PGM-out into CasparCG for post processing which is an expensive step latency wise (4-5 frames at least)

You could do this fairly easily using an HTML template and using a CSS blur effect in the overlay box. e.g. -webkit-filter: blur(5px); filter: blur(5px);

No, the HTML template does not have access to the live background video.

Ah yes, it wont work unless you can play your video through the template as well. This works ok for an mpg but guess its not going to for live