After Effects Rotobrush Equivalent

[ingyaningya]

I know that rotobrush is the best tool for rotobrush, but my computer is an older one, and is not compatable with CS5. There is a program called Fluid Mask that does is, but that only works with still images. Is there a program, in or out of After Effects, that works with a video file, and automatically make adjustments by itself, like rotobrush?
Thank you.

 

[amigo]

There isn't another software that I know of.
But you can add a mask around your subject, and using the keyframes of path of that mask, you can move it to follow you subject throughout the video.

Obviously this will take you much more time than using the Rotobrush tool, but it can be done.