I just .rar'd two 80mb files into a 122kb rar file... how?

[Morgan C]

Two .wav files, each 80mb (not sure why they're so big, should be 30mb but must be stereo and/or higher bitrate or something). Just trigger tracks for a kick. Yet the rar file is 122kb. How the fuck did this just happen?

I'll post the link since it's not particularly private or anything, just triggers.
http://dl.dropbox.com/u/324723/LeoSong1&3KickTrigger.rar

 

[Harry Hughes]

In response to thread title

 

[Ermz]

The algorithm probably notices most of it is blank space and throws the data away. It probably also realizes you're using a single repeating trigger tone and encodes accordingly. Clever algorithm!

@Harry: Fucking

 

[Wolfeman]

It's because of the way compression algorithms work. There is a lot of blank nothing on trigger tracks so it just voids the empty space. Well it doesn't really void it per say, but the original file has a lot of recurring data in a row so it can smash it all down.

Kinda hard to explain if you don't know how data compression works.

 

[Wolfeman]

Damn Ermz beat me to it

 

[JeffTD]

Yup, these guys have got it. That's why a ton of upload/download time can be saved when transferring tracks if you chop out obvious bleed in tom tracks without fine-tooth-combing them - it takes silence or near-silence and more or less throws it away.

 

[kev]

Yep it happend to me a while ago, and I was freaked out momentarily too, to the point where I unpacked it multiple times and redownloaded to check for error

 

[AgentX]

Have a read of Huffman or Lempel–Ziv–Welch compression techniques, interesting stuff if your curious about how it all works!

 

[ahjteam]

There was this russian guy Dmitry Andreev at Assembly 2003 (a computer demo gathering) one year who made a 64kb intro demo and compressed it with his own algorithm and it was pretty astonishing. And surprise surprise; it won.



He also made a pc compression utility for it: http://and.intercon.ru/releases/tools/andpakk2/

 

[SavageDoom]

I'd have to give the 64k demo "honour" to Farbrausch. I thought it was pretty insane when I saw "fr-08: .the .product" a while after it came out. It was released in 2000 I believe.

http://www.theproduct.de/

They also use(d) executable compression:
http://www.farb-rausch.de/~fg/kkrunchy/

Nevertheless, the best general compression I have found is 7-zip.