Oook. Where to start.
Let's put aside the obvious fact that you're a total retard with no concept of how to spell, let alone what he's talking about.
To the point:
mplayer is not a tool, it is a media player.
I'd assume it has its own built in codecs if you can play h264 files without external codec packs.
I don't know what you think you're playing, but most people with 'low cpus' can play SD encodes without too much trouble... unless their PC is an utter piece of shit.
... then again, I don't know why I'm explaining this to you, since you're ignorant... and banned.