Need Help Saving Transparent background Video Using Greenscreen

Darkgarza wrote on 9/6/2023, 6:44 AM

While it’s very easy to remove the background in video that is shot on greenscreen in Vegas Pro 19 and put it over other video clips on a timeline, I am trying to figure out how to save video after it has been chromakeyed with a transparent background. I stream content online and having the ability to save transparent background clips that I chromakeyed would allow me to be able to add alert graphics without having to save them with bright green backgrounds and then having to use a chromakey filter in my streaming software which sometimes distorts the video clips color. As of right now every time I attempt to save the clips, they do so with black backgrounds and I don’t see the grey checkerboards as backgrounds when I drop the clips I make back into Vegas after I render them. I tried rendering in MOV but I still get the black background not the grey checkers when I reload it into a timeline after rendering. Does anyone know if what I am trying to do is possible using Vegas Pro or Post? (I currently use Vegas Pro 19)

Comments

Dexcon wrote on 9/6/2023, 7:00 AM

Yes, it is possible ... but with what could be a big disadvantage.

In Render As, choose the 'Video for Windows' format, then choose the most appropriate template - it can be customised for frame size and frame rate. Then set the 'Video format' field to Uncompressed and check the 'Renderr alpha channel' checkbox -

Anything black in the video will be alpha (or should be).

The big disadvantage ... the rendered file will be huge.

RogerS wrote on 9/6/2023, 7:06 AM

Would ProRes 444 with alpha channel work?

mark-y wrote on 9/6/2023, 7:37 AM

I am trying to figure out how to save video after it has been chromakeyed with a transparent background. I stream content online....

Easy enough to do in Vegas, using one of a limited number of formats that use an Alpha layer.

Unfortunately, there is no normal streaming or delivery protocol I know of that accepts any of those formats. If you are curious about learning web-based HTML5 for browser delivery, which is a very complex topic, there is an introduction here:

https://rotato.app/blog/transparent-videos-for-the-web

Vegas does not generate HTML5 code or VP9 video.

Darkgarza wrote on 9/6/2023, 8:17 AM

Yes, it is possible ... but with what could be a big disadvantage.

In Render As, choose the 'Video for Windows' format, then choose the most appropriate template - it can be customised for frame size and frame rate. Then set the 'Video format' field to Uncompressed and check the 'Renderr alpha channel' checkbox -

Anything black in the video will be alpha (or should be).

The big disadvantage ... the rendered file will be huge.

Thanks this worked. While it didn't work directly as I had hoped (stream elements doesn't support avi or mov) It was enough to help me do a work around. Many thanks for the help.

Darkgarza wrote on 9/6/2023, 8:42 AM

Would ProRes 444 with alpha channel work?

Thanks that worked too.

Dexcon wrote on 9/6/2023, 8:45 AM

@Darkgarza ... just as a matter of interest, was there any significant difference in the sizes of the rendered files between Video for Windows and ProRes 444?

Darkgarza wrote on 9/6/2023, 9:23 AM

@Darkgarza ... just as a matter of interest, was there any significant difference in the sizes of the rendered files between Video for Windows and ProRes 444?

19sec 1080p 60fps file in AVI was 9.07gb and 444 (XQ) 9.34gb