- functions and codec.
The method pf checking functions usually depends what function you want/need to check. As to checking codecs, are you referring to determining which codecs are needed for a particular file or checking to see if a required codec is supported by your system configuration?
How can you do that?
Depends on what you are doing as mentioned above and/or what apps utilities you already have installed/need to install on your system. Again, you need to be more specific when asking questions.
And if needed reinstall?
Normally you woulde first determint if the problem is caused by the operating OS, player app, account preference, missing codec, or lack of container support and install or re-install what is needed.iMac, OS X Mountain Lion (10.8.4), 3.4 GHz Quad Core i7, 12GB 1333 MHz