1) You don't need codec packs. Ever! if you have any uninstall them now.
2) LAV filters, among others, are 3rd party filters that (supposedly) do a better job than the ones built in to the player, i.e MPC-HC. Most people won't be able to tell the difference and will be quite happy just running the player as is.
3) SVP is a software package that provides high framerate (HFR) playback of standard framerate video by using a method called frame interpolation.
If you want a nice easy life, go download MPC-HC, install it, and start watching some good movies. Job done.