MPEG 4 decoder packs with DirectShow capabilities include codecs that allow you to play specific video file types on your computer. They handle videos encoded with DirectShow technology, including DivX, Xvid, MPEG-1, MPEG-2 and WMV media files. Some PCs come with DirectShow codecs installed but in most cases you will need to download and install a free codec pack from the Internet.
Go to the download website for the DirectShow-compatible MPEG 4 decoder pack.
Click the Download button. Select the correct codec pack for your computer operating system. Click the link to download the file directly to your hard drive.
Double-click the installation file. Keep clicking the Next button and then click the Install button to start the installation. Try playing a DirectShow MP4 video on your computer's video or multimedia player application, such as Windows Media Player or VLC Media Player.