How to ULTRA compress file?

Question

It is known that 7zip is able to ultra compress file. Example, a 70Mb 7-zip file contains a 2Gb file. I downloaded such file before. However, I fail to demonstrate such capability with 7-zip myself. How others did it?

Answer 1

depends on what you are zipping
if its a movie , mp3,or photos ( they are compressed a lot by the encoders) you aren't gonna zip 2 gig to 70.
the only kind of file You could zip like that would be a fullframes uncompressed video clip....
but then encoding it would do the same job.....
if you had a 2 gb uncompressed video of blank shots, that could comress that small or even smaller....