its a question related to compression of files(winrar)?

Question

which file compresser has the most powerful compressing (i have seen 700mb compressed in to 3mb) & how do they compress those files to such small sizes ,plz explain in detail (preferably in winrar) thanks for every one who answers

Answer 1

personally, I use WinRAR. I'm not sure if it THE best since I haven't used everything that is out there. Here's is what I DO know. I just compressed about 10 databases. The total uncompressed size is 1.11GB. It compressed it down to 100MB.

Different types of files can be compressed more than others. Different types of compressors do it differently. To give you example of one way compression can work:

All files are just data. They are a series of 1's and 0's arranged in a way that makes sense to a computer. Each 1 or 0 is called a bit. 8 bits equals 1 byte. 1000 bytes is a kilobyte. 1000 kilobytes is a megabyte... and so on. Let's say you go to compress a Word document that is 100 pages long. Every time you see the word "THE" in the document, it is basically a series of 1s and 0s. When you start compressing the document, the computer will look for a series that occurs over and over again. Every time it sees that series, it will replace it with something.

So, let's say it replaces the word "THE" with the number 1. Let's say it replaces the word "WHEN" with 2. Let's say it replaces every word over 4 letters long with a number. As you can see, you have basically shaved off a whole lot of letters from the document. The compressing software has basically ENCODED the document. That is why they cannot just be opened again by simply double-clicking them. The have to be uncompressed, or decoded, first. And each compressor does its coding and decoding in a different way. Some are better, some are worse.

Answer 2

Winrar is the BEST because:

Using winrar with best compression settings. also you can compress your hardrive to save space.
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You should be aware of three things:

Compressed and encoded files are usually identified by their extensions, the character code following the file name. Depending on how they were compressed, some files won't decompress or decode if the extension is removed. Here are some common extensions for compressed and encoded files:
Compressed files

filename.Z (a compressed file)
filename.gz (a GNU compressed file)
filename.z (a GNU compressed file -- note lowercase 'z')
filename.zip (a zipped archive)
filename.tar (a tarred file)
filename.tar.Z (a file both tarred and compressed)
filename.tar.gz (a file both tarred and GNU compressed)
filename.tgz (abbreviated form of tarred and GNU compressed)
filename.bz (a file compressed with bzip)
filename.bz2 (a file compressed with bzip2)
Encoded files

filename.uu (a uuencoded file)
filename.hqx (a binhexed file)


The names of compressed and encoded files may change when the files are decompressed or decoded. For example, the file "test.uu" could be called "first_test.txt" after it's decoded. Likewise, file.Z would become file. You may need to look carefully at your directory listing to find the new file.
Decompressing or decoding a file creates a new file or files, but it doesn't necessarily remove the original compressed or encoded file. You usually have to remove the original when you're finished with it.
Decompressing files with .Z endings
To decompress a file with the extension .Z (uppercase), enter the command

compress -d filename.Z

The decompressed file will appear in your directory listing, and the original .Z file will be removed.

Warning: If you run out of available disk space during the decompression, you'll lose both the decompressed file and the compressed file. The gunzip command below can "safely" decompress a .Z file.

So, you see using Winrar would be the Best file compresserto be used.

Hoping you have understood.

Answer 3

All compression programs have the same basic principle. In a stream of data, there is bound to be some level of repetition, even randomly. Compression works to remove that repetition and replace it with a smaller representation.

For example, say we had "cababcabcabc". Well, if we say 0=ab and 1=c, we can replace that with "10010101". The original string would take up 8 bytes of space, or 64 bits. Our compressed version would take up 1 byte, or 8 bits. So we achieved a compression factor of 8. This is a very simple example, of course, but it serves to illustrate the point.

Different compression methods work different ways, but they all try to achieve this goal as well as they can. The .zip compression uses a method called LZW (which is a patented algorithm). Winrar uses a proprietary compression algorithm developed by Eugene Roshal.

Answer 4

I use win zip. But i dout it will compress any thing as much as you said. I have never seen one compress a file or a program that much.

I know this does not realy answer you question about how they work. Sorry i have no clue how they compress it, but i asume they convert the data into there own type of data that is smaller and more compact.

Answer 5

I use AlZip, it supports many different compression formats (zip, rar, ace, arj, etc.). Get it and try each of them to find out which will work best for you.