Why does compressing sometimes not work?

[Craig321]

Hi,

Just a quick question:

How come sometimes I can compress a file and loose 100mb++ off it, but then other times I compress a file and loose a few KB off it.

I always do it the same way and use the same compression program but just don't get why it does that?

Thanks,
Craig.

 

[Craig321]

So basically it'll suck at compressing already compressed files (as said above, mp3, compressed videos etc.)?

Thanks for clearing it up for me

Craig.

 

[Craig321]

Hehe nice, just compressed 1mb of ones to 192bytes

Craig.