if u feel like waiting a couple hours or even 10+ there's compression method that has a compression ratio of about 2 to 1, altho I never cared about compressing sumthing that much as to wait hours and hours, so I can't verify that 100%, but I'll give u tha link if u want
7-zip
and if I'm not mistaken, winace has a similar compression method
WinAce
for both of them u have to choose the compression method