What video player are you seeing this difference in? QuickTime Player? If so, try a different video player and see if the same difference apears. QuickTime Player is notoriously bad about doing automatic (and often incorrect) gamma adjustments as part of its color management.
Thanks a lot for your answer.
No I'm using VLC, but anyway, when I put this file in other programs like sony vegas, etc, result is good, but with after effect there is always too much contrast ... I really dont understand
It's probably your color management settings in AE. What are they? Do you know where to look for them? What kind of video? What OS?
Yeah it's probably something like that, but I don't no where they are, can you explain me ?
(I want to precise that I don't apply any effect to got it, I just import and and BOOM : overcontrasted)
Thanks in advance
OS : Win7 64bit
An avi video (game editing)
It's probably your screen capture AVI. Look in the help files or search color management in the search window at the top right corner of AE. There are a bunch of resources.
Generic color management primer for screen content (not AE, though):
And yeah, seriously read up on that stuff - color management stuff and how different CoDecs use different Gamma and may appear differently on different platforms and players...