It's a codec pack and it contains media player classic which u don't have to install. Contains the latest versions all the video and audio codecs you'll ever need. It's just more convenient than lookin for individual codecs. However u can always do a custom install and select only the ones you require.
This one's only 1MB contains certain codecs which should let u playback 3gp but hasn't been updated in a long time : 3ivx D4