[FFmpeg-user] How to brighten part of a dark video?

[Gilles]

Hello

I need to work on a video where the speaker was badly lit but also had
a very bright screen to show slide:

http://s11.postimg.org/6kdnh7nwj/vlcsnap_2015_09_18_11h21m29s599.png

I read about the "mp" filter here:
https://wjwoodrow.wordpress.com/2013/11/22/adjusting-video-contrast-brightness-saturation-and-color-balance-with-ffmpeg/

Can ffmpeg brighten up only the dark part of the video without
increasing the brightness of the screen that's already too bright?

FWIW, I downloaded the latest Windows package (N-75316-gcbbd906).

Thank you.