I\'m using CefSharp Winforms x86 build. I want to play a video from this link :
http://developers.canal-plus.com/rx-player/
In google chrom
CefSharp is based on CEF which is based on Chromium. Chromium does not support proprietary audio and video formats only Google Chrome does (see Chromium documentation).
If you need proprietary codec support you need to build CEF/Chromium on your own. There are no plugins/extensions which enable this functionality.
See also previous SO questions related to this topic 1 2 etc.