Apply adjustment brush area to video in Lightroom 5.3

Question

I have a video of a person talking looking straight to the camera, on a grey-ish background (he is standing still in the same position across the whole video, just moves his head a tiny bit), goal is to make the background from grey-ish, to white.

So... i'm capturing a frame of the video, and then with the adjustment brush im selecting the area around his body (the grey-ish background), and im doing the necessary adjustments to that area (increasing exposure and contrast a bit) and the result is very good. The person remains untouched and the background is almost pure white. Great.

Then, im selecting both the captured frame which carries the effect and the video and pressing "Sync" so video will get that effect also. But no effect is added to video.

Is this possible with Lightroom? (If not, then what program can be used to achieve this? I do not want to apply effect globally, just to the greyish background)

Answer 1

Answering my own question: You cannot apply one adjustment brush area to the whole video in Lightroom 5.3. You can only apply it to a single frame.

Also, i managed to get the result i wanted (background pure white) but not just by post-processing. I had to shoot again.

Method 1) Used more lights, enough to make the area around the person pure white. Then i used lightroom to make the edges pure white too.

Method 2) Shooted person against green background, then used adobe after effects and specifically the "Chroma Key" to make anything green to transparent, then applied a white background.