MP4

I have a couple of videos that are in mp4 format and I can't get MPC to play them. I've already tried a bunch of codec packs with no sucess. What am I doing wrong?

Did you try CCCP?

The CCCP (Combined Community Codec Pack) is a DirectShow filter pack specifically built for playing anime. It has been assembled by some of the most knowledgeable people in online anime distribution, and one of the primary design goals is to play as much as possible with as little as possible. The CCCP attempts to be as unintrusive on your system as possible.