Use ffplay to check how much to brighten video before using ffmpeg? I have a video which is a bit dark that I'd like to re-encode and brighten up with ffmpeg.

As a smarter/faster alternative to running ffmpeg in trial/error mode, is there a way to simply use ffplay to find how much to brighten things up, before running ffmpeg with the same settings?

"ffplay -h" returns so much infos that it's hard for newbies :-/

Thank you.
You can use simple filtergraphs easily with ffplay.

Example using colorlevels filter in ffplay:

ffplay -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 input.mp4


Then you can use the same filter in ffmpeg:

ffmpeg -i input.mp4 -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 -c:a copy output.mp4


This example will stream copy the audio.