RAR compression

[james636]

I was wondering if anyone can help me figure out how to get better compression results with WinRAR and WinAce. I have a file that was compressed by WinRAR to a size of 185MB. But when I unpacked the rar file, The contents' size was an unbelievable 8.5GB . I know, I know, some of you are say to yourselves, "man he's over exaggerating", But I'm not. Really, you've got to believe me. Whenever I attempt to compress something usin WinRAR or WinAce, the best I can do is knock off a meesly 10-20 MB of an original 1GB file . In the compression settings, I choice the smallest file option, but still I don't get very much compression. How in the heck did the person that I got the file from manage to compress an 8.5GB folder down to only 185MB. I wish that I still had my roadrunner internet cable service instead of this slow dial-up, so that I may send the file in question to those that think I'm lying. This way, there will be those, other than myself amazed of this compression. If there is someone that reads this and knows how to acomplish such compressions, please fill me in on how to do it.

[ViRaL1]

1 portion may be 185MB, but if WinRAR could compress 8.5GB to 185MB, there wouldn't even be a free trial.

[bigmicka]

it all depends on the contents of the rar file.

is it made up of word documents? or mp3 files + mpegs?

some file types are far more compresible than others.

mic

[Conquest10]

Don't know how it happened but the other day I used winrar to compress a 3 gig quicktime file to 600mb.

[bigmicka]

conquest, did the quicktime file have alot of movement? or was it made up of alot of the same content over and over again?

mic

[thecoalman]

it all depends on the contents of the rar file.


mic

Regardless I've never heard of anyhting getting compressed at a 46:1 ratio. I not completeley familiar with RAR but I do know they come in parts, I think he's not adding up the rest of the parts.

[ViRaL1]

The thing is, WinRAR knows how large the source file is supposed to be. As soon as you start extracting, it will allocate space for the entire file whether the full contents of the archive are available. It doesn't resize it as it goes. So let's say it's split into 30 files, extracting any part will show 8.5GB. It will be unusable, but it will show the proper size.

[james636]

1 portion may be 185MB, but if WinRAR could compress 8.5GB to 185MB, there wouldn't even be a free trial.

So Viral1, you don't believe me huh? How about I send you the file so that you may see for yourself. Like I stated in my first post I have dial-up so it would be incredibly so. After you recieve the file and realize that what I stated was true, then I think that a public appoligy is in order. Deal? Just let me know what method of file transfer do you perfer?

[ViRaL1]

I don't doubt what you're saying is true. I just question the validity of the source file extracted from it.

[bigmicka]

i still want to know what is in the rar file?

mic

[thecoalman]

Just let me know what method of file transfer do you perfer?

By my calculations that would take 154 hours with a dial up modem.

[ViRaL1]

Judging from the source file size I'd bet video, probably an ISO or the VIDEO_TS folder. I'm sure I could beat that compression. I'll just find the biggest ISO I have and choose the option to split into floppy-sized files. 1.44MB to 9GB+. Pretty sweet huh?

[thecoalman]

Do you have a link?

[bigmicka]

it all depends on the contents of the rar file.


mic

Regardless I've never heard of anyhting getting compressed at a 46:1 ratio. I not completeley familiar with RAR but I do know they come in parts, I think he's not adding up the rest of the parts.

have you ever compressed a powerpoint file?

i can remember someone at work who created a powerpoint 97 file, but the recipient of the file only had 95. the person with 97 decided to save as 95, when there 8mb 97 file turned into a 225mb 95 file they thought something was wrong. i put the 225mb file into winzip and it nearly fit onto a 1.44 floppy.

mic

[james636]

So along with ViRaL1, bigmika doesn't believe me. Like I said, you guys name the means of tranfers and I'll prove it!!!!

Regardless I've never heard of anyhting getting compressed at a 46:1 ratio. I not completeley familiar with RAR but I do know they come in parts, I think he's not adding up the rest of the parts.

The file wasn't compressed using the rar volume method: 00.rar, 01.rar, 02.rar. It was compressed using the Solid archiving method, so there was anything to add up.

[bigmicka]

james before accusing me of anything, all i have asked is what the file contains. to this point you havent answered it. then i put on an example that could explain what you are talking about, if i knew what was in the file, and you say i dont believe you.

i try and help you understand and all you do is shoot me down, why dont you go get fucked next time instead of trying to get an answer for something you dont want an answer for.

mic

[thecoalman]

So along with ViRaL1, bigmika doesn't believe me. Like I said, you guys name the means of tranfers and I'll prove it!!!!

Actually Bigmicka is on your side of the fence providing it's a text file I'm assuming.

[ViRaL1]

So along with ViRaL1, bigmika doesn't believe me. Like I said, you guys name the means of tranfers and I'll prove it!!!!

Regardless I've never heard of anyhting getting compressed at a 46:1 ratio. I not completeley familiar with RAR but I do know they come in parts, I think he's not adding up the rest of the parts.

The file wasn't compressed using the rar volume method: 00.rar, 01.rar, 02.rar. It was compressed using the Solid archiving method, so there was anything to add up.

That's not how the file naming goes. The first file is still named Filename.rar, then the subsequent files are named Filename.r00, Filename.r01 etc. So the naming of 1 file doesn't really tell us much. Without any proper names (titles etc) tell us what data the source file contains. If it is indeed video, it would probably have to be a still shot of a black background with no audio for an 8.5GB file to compress down to 185MB. I'm no video expert so that estimate may be a bit off, but I'll wait until I hear what's in the file before I say more.

[james636]

Sorry bigmicka, I guess I got a little carried away. It contains some ps2 cheat and utilities cd + misc tools. I hope you aren't going to make me name each of the items.

[ViRaL1]

I'm still skeptical myself, but IF we say that all of the data really IS intact and in it's entirety, then the answer to your original question of what you can do is this. Only use highly compressible data. Nothing fancy to it, but nothing you can really DO.

[thecoalman]

If it is indeed video, it would probably have to be a still shot of a black background with no audio for an 8.5GB file to compress down to 185MB. I'm no video expert so that estimate may be a bit off, but I'll wait until I hear what's in the file before I say more.

DVD compliant MPEG2 320x240 600kbs video (black) no audo came out to around 60 mb per minute if I remeber correctly.

Edit:that's wrong its ntsc dvd compliant 353x240 434kbs black video no audio is 7 mb per minute....

[james636]

"That's not how the file naming goes. The first file is still named Filename.rar, then the subsequent files are named Filename.r00, Filename.r01 etc. So the naming of 1 file doesn't really tell us much"

There are no subsequent files; .r00, .r01, .r02. There is only filename.rar and that files is 185MB

[bigmicka]

so some of the file contains cheat files which would be straight text and utility cd's and miscelaneous tools.

here is a link explaining huffman coding

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

which is the basic fundementals of file compression, this states that you can compress a file to an even greater extent than being a string of 8 1's and 0's, if you eliminate sections of the ascii table you dont need to have an 8bit long string to represent each character. you can do some practicle experiments on this if you really wanted to, which would really be a waste of time unless you thought you could squeeze some more space into a zip file.

generally video and music files are already compressed to a high level, unless your talking about a wav to mp3 compression when it actually cuts out ranges of the audio file that the human ear connot hear. where as a straight text docuemen if grouped together with only the contents of the file (ABCD) can be greatly reduced with the technique i have provided above.

mic

[james636]

OK, have you guys ever downloaded a zipped trial version of something; example: DVD Decrpter 3.49.zip. Well thats how I downloaded this file. There were absolutely no subsequent files; Filename.rar- .r00, .r01, .r02

[ViRaL1]

OK, have you guys ever downloaded a zipped trial version of something; example: DVD Decrpter 3.49.zip. Well thats how I downloaded this file. There were absolutely no subsequent files; Filename.rar- .r00, .r01, .r02

What I'm saying is that if an archive was created as a split archive the original archive filename would still be the same (Filename.rar).

[bigmicka]

coalman the description of an all black video file with no audio is an apt one in this case.

taking your 60mb a minute it would take a long time to fill up a 8.5gb file, but if it was an 8.5gb file of the one image just repeated over and over again, alot of the same characters will be used over and over again within the contents of the file, leading to the perfect environment for high compression using the huffman technique.

mic

[james636]

bickmicka, I have no clue what you just said; man you're way over my head But if you are suggesting that the reason the file has such great compress because its mostly text is not true. It contains about 20-30 folders. five of the folders contain Codebreaker and Gameshark ps2 utility ISO images ranging from 700MB to 4GB.

[james636]

So I guess there is know answer to my original question.

[thecoalman]

bickmicka, I have no clue what you just said; man you're way over my head .

What he's saying is the amount the data can be compressed is dependant on the content. For example if you have 600x600 image in jpeg format that has many different colors it won't compress nearly as much as the same size image that is all black using the same compression for both images.... If you have a bunch of Jpg's that are all the same size you can look and see that the file sizes vary.

[thecoalman]

taking your 60mb a minute it would take a long time to fill up a 8.5gb file,

actually it's 3mb per minute for black and about 7 mb perminute for regular video. I was guessing those sizes from some tests I did in the summer. I'm pretty sure I was able to even reduce it more. I did a few tests when the question popped up how much video can you fit on a DVD.
https://www.videohelp.com/forum/viewtopic.php?t=237159