File Compression.

[Llareggub]

I bought a game yesterday for my son, Aliens vs Predator. It came on 1 single layered DVD, 4.7 GB.

When we went to install it, it asked for a drive with 32GB available space!

Then the PC found a virus. (Avira on Winxp) I immediately switched everything off and was about to put the disk in the bin.

I had second thoughts today and checked it on my machine using a different Anti Virus (Avast - 64 BIT) and it said no infection.

So with great skepticism, I set about installing this disk on my sons PC.

And would you believe it...IT WORKED!!!

How on earth can 32GB be compressed onto a single standard DVD....it has me beat!

[astral]

http://en.wikipedia.org/wiki/Data_compression

will give you some idea.

Zip is a commmon programme for compressing files before sending or archiving.

[Llareggub]

http://en.wikipedia....ata_compression

will give you some idea.

Zip is a commmon programme for compressing files before sending or archiving.

I know ZIP and RAR, but how on earth do you compress 32 GB onto a 4.7GB disk?

Winzip and WinRAR have never done that before, hence the reason on some downloads I need to buy dual layer disks!

If it was that simple, then everything would be on single layer!

take for example VFR Germany for FSX, it is 4 x 4.7 GB, so they need 4 discs at standard size to install, if your methodolgy was as you claim, why could they not have put the entire 28GB on one single disc!

I think you don't understand this in the least...Winzip has been around for at least ten years, it's old hat, this stuff is clever!

If you could give me a practical example of Winzip compressing 30GB onto a 4GB disk I might take you seriously

[siamect]

And would you believe it...IT WORKED!!!

Of course... what is the point of delivering a virus if it doesn't work?

Yet another one filtering out information just because it doesn't make you happy...

My favorite virus distributor... If someone tells you to be careful because it may be dangerous and another one doesn't have a clue,what do you do?

Martin

[ZZZ]

How much you can compress depends entirely on what kind of information you have in the file.

If you take a picture with your camera of a subject with a lot of different colors, shades and shapes the camera will compress that to a .jpg file. If you then take a picture in a completely dark room the camera will do the same but the resulting file size will be much smaller as there is much less less information in that picture.

Same if you compress a text file with a lot of different characters the resulting zip file will be much larger than if you compress a text file where you have typed in the same character again and again.

Compression will just remove all the redundant information in the file.

[Llareggub]

but 32GB onto a 4.7GB, I know a little about compression, compressing JPG will not make much odds as it is already compressed, but how on earth do you compress 32Gb onto a 4.7GB disk...that is the question.

[Llareggub]

And would you believe it...IT WORKED!!!

Of course... what is the point of delivering a virus if it doesn't work?

Yet another one filtering out information just because it doesn't make you happy...

My favorite virus distributor... If someone tells you to be careful because it may be dangerous and another one doesn't have a clue,what do you do?

Martin

Virus or not, you simply still cannot answer the question as to how 32GB can be compressed to a 4.7GB disk!

[TigertheCat]

Its possible that whilst the program is installing it also uses various Windows programs for example ".net framework" to install correctly so the final install becomes much bigger than the size od disc or when unpacked.

Just a thought

[Tywais]

A couple of reasons could explain it besides the compression. Using Windows 7 installation as an example - MS says you need 16GB free space to install it but after install it only takes up about 6-7GB. This is due to decompressing the installation files into a temporary work directory on the hard drive. When the installation is done, most temp files are removed.

2nd, games often have maps & scenes and these may be generated on the fly during the installation using data sets or vectored data from the DVD that is then turned into image bit maps.

In other words, it asks for a minimum amount of space for the installation but that doesn't necessarily mean that is the final amount of space being used.

//edit - looking at the specs of the game on another forum (steam) it says the final disk space used is 15GB.

[raro]

How much you can compress depends entirely on what kind of information you have in the file.

If you take a picture with your camera of a subject with a lot of different colors, shades and shapes the camera will compress that to a .jpg file. If you then take a picture in a completely dark room the camera will do the same but the resulting file size will be much smaller as there is much less less information in that picture.

Same if you compress a text file with a lot of different characters the resulting zip file will be much larger than if you compress a text file where you have typed in the same character again and again.

Compression will just remove all the redundant information in the file.

looks like computer games are quite redundant...

[nikster]

but 32GB onto a 4.7GB, I know a little about compression, compressing JPG will not make much odds as it is already compressed, but how on earth do you compress 32Gb onto a 4.7GB disk...that is the question.

There's a big difference between what a program asks for, and what it's actually using. Check how much it's using with JDiskReport or another free tool that tells you disk usage.

Other than that, you can easily get 10:1 compression if you have "fluffy" content. For example, XML often compresses 100:1 - that means there's lots of redundant information in it. Then there's the chunk size of the hard disk - smallest file size is say 4KB. Then, if you have thousands or hundreds of thousands of files, each will waste on average 2KB. This waste is removed by compressing the files to a single big compressed file.

[siamect]

Virus or not, you simply still cannot answer the question as to how 32GB can be compressed to a 4.7GB disk!

Maybe you haven't read the link Astral gave you... Maybe that is to much work for you?

But what you should ask yourself is if your question is relevant or not...

Martin

[Llareggub]

A couple of reasons could explain it besides the compression. Using Windows 7 installation as an example - MS says you need 16GB free space to install it but after install it only takes up about 6-7GB. This is due to decompressing the installation files into a temporary work directory on the hard drive. When the installation is done, most temp files are removed.

2nd, games often have maps & scenes and these may be generated on the fly during the installation using data sets or vectored data from the DVD that is then turned into image bit maps.

In other words, it asks for a minimum amount of space for the installation but that doesn't necessarily mean that is the final amount of space being used.

//edit - looking at the specs of the game on another forum (steam) it says the final disk space used is 15GB.

Well, it is a bit weird, and yes it does install a few windows compiler and binary bits and pieces, but it has physically hogged almost 32GB of space. (after the install which took nearly 2 hours) I looked at the disk it contains a few of those BINARY files, but nothing of any great size.

When I initially tried to install it on my sons machine the antivirus picked out a problem with the SETUP.EXE file, his machine is windows XP 32 bit, using Avira.

I tried it on mine and scanned it with Avast 64BIT for windows (win7 ultimate) and Antimalwarebytes, and they passed it as clean.

To be honest I am not sure if I trust this Avast 64BIT or not, it doesn't seem to ever find anything, and the things I download....well, it makes me a bit suspicious.

I was simply amazed that there was a way to compress 32GB onto a 4GB disc, that was all!

I was going to start a new topic but I thought maybe try here first.

Anyone have any idea why a wireless mouse (Kensington Pilot) would, after simply changing the batteries begin a sort of "polling" routine?

The USB connector to the PC has begun flashing the green connection light every three seconds, it never did this before, and it does it with the mouse switched on or off...kind of irritating. Appreciate any ideas!

[Llareggub]

but 32GB onto a 4.7GB, I know a little about compression, compressing JPG will not make much odds as it is already compressed, but how on earth do you compress 32Gb onto a 4.7GB disk...that is the question.

There's a big difference between what a program asks for, and what it's actually using. Check how much it's using with JDiskReport or another free tool that tells you disk usage.

Other than that, you can easily get 10:1 compression if you have "fluffy" content. For example, XML often compresses 100:1 - that means there's lots of redundant information in it. Then there's the chunk size of the hard disk - smallest file size is say 4KB. Then, if you have thousands or hundreds of thousands of files, each will waste on average 2KB. This waste is removed by compressing the files to a single big compressed file.

That is interesting thanks, I simply did not think it was possible - Why the big difference in the way games are compressed? I have a few downloaded games that are about 13GB in size, and need to be mounted or burned virtually as is, i.e when you extract them they are compressed no more than about 5%, how come these guys get the 30GB onto a 4GB disk...

I had to buy some dual layer disks just to install a few games yet this thing is amazing!

[Llareggub]

Virus or not, you simply still cannot answer the question as to how 32GB can be compressed to a 4.7GB disk!

Maybe you haven't read the link Astral gave you... Maybe that is to much work for you?

But what you should ask yourself is if your question is relevant or not...

Martin

EDIT - Apologies I am a BLIND GIT!

[Llareggub]

A couple of reasons could explain it besides the compression. Using Windows 7 installation as an example - MS says you need 16GB free space to install it but after install it only takes up about 6-7GB. This is due to decompressing the installation files into a temporary work directory on the hard drive. When the installation is done, most temp files are removed.

2nd, games often have maps & scenes and these may be generated on the fly during the installation using data sets or vectored data from the DVD that is then turned into image bit maps.

In other words, it asks for a minimum amount of space for the installation but that doesn't necessarily mean that is the final amount of space being used.

//edit - looking at the specs of the game on another forum (steam) it says the final disk space used is 15GB.

Tywais,

you are in fact correct,

After I rebooted his machine the used space of the program has gone from 32GB to 14GB, apologies for my ignorance!

Thank you, appreciated!