For professional work cases, Linux is a very good choice. You don’t need to pay for the corporate windows licences and security is overall better than windows since security by obscurity is a no no which windows intends.
Try going with a solid distro. Use mint or fedora. I would recommend you use the KDE desktop environment as it is very sleek and matches the windows look.
As for your video codec issue, if you are using distros which “respect” American patent laws, use the world wide versions. For example in Fedora, you must install the free world versions.
And the most important tip for you switching to Linux, ask questions and read up if you get stuck on something, however trivial you might think the issue is. The community is very open and very supportive.