Compression decreases the size of data.

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8
votes
6answers
15k views

How can I achieve the best, standard ZIP compression?

I don't care how long it takes to compress, all I want to achieve is two things: The absolute best possible compression ratio Compatibility with standard readers, such as Windows and WinZip So ...
3
votes
2answers
749 views

Best video codec to store my own collection

I think this question has already been asked but with different flavours. My problem resised in the fact that my camera (Canon G9) creates video with almost raw codec (I think it's plain old MPEG) so ...
7
votes
2answers
176 views

CPU-adaptive compression

Let assume I need to send some data from one computer to another, over a pretty fast network... for example standard 100Mbit connection (~10MB/s). My disk drives are standard HDD, so their speed is ...
0
votes
2answers
2k views

“Unsupported compression method 98” error when unzipping a file. What tools support it, other than WinZip?

I'm getting an error message: "unsupported compression method 98" when unzipping a file somebody sent to me. I've tried both an older version of WinZip, and 7-Zip 4.65. (Update: I've also tried ...
19
votes
2answers
13k views

Is zip's encryption really bad? [closed]

The standard advice for many years regarding compression and encryption has been that the encryption strength of zip is bad. Is this really the case in this day and age? I read this article about ...
1
vote
3answers
4k views

How to compress files with batch file?

I used COMPACT but it didn't compress the file except changing the file color from black to blue. I only used COMPACT c:\fileToZip.bak /C Did i make wrong?
11
votes
3answers
16k views

7-Zip compression on multi-core computers

Does 7-Zip take advantage of multiprocessor or multi-core systems when compressing? For example, would there be a close to 16 times speed-up on a 16 core system assuming no disk or memory ...
1
vote
1answer
155 views

Compressing a file from command line [duplicate]

Possible Duplicate: Compressing files in windows I want to compress a file using the command line. This command-line C: compact /c aa.xml returns a successful message but I can't see any ...
1
vote
1answer
3k views

How to mount a compressed ISO image?

I have problem to mount a compressed (ISZ) image under Linux, which was created by e.g. UltraISO? I am aware about user-space fuseiso, but it fails to mount these images, as I have reported in Debian ...
1
vote
0answers
356 views

Video compression artifacts in Flash

This only started happening in the past two days, which seems very odd to me. Everything worked flawlessly up until now, and I use my my computer as my primary TV. Flash video from Hulu and Amazon, ...
22
votes
5answers
41k views

What is the maximum compression ratio of gzip?

What is the largest size a gzip (say 10kb for the sake of an example) can be decompressed to?
10
votes
5answers
10k views

How to unpack a chrome theme?

How to unpack a packed chrome theme(*.crx)? Their FAQ states how to pack, but not how to unpack.
2
votes
2answers
2k views

Reduce FLV file size

I have successfully converted an AVI file to FLV, but it's too large a file. How can I reduce it's file size without editing out any portions of its content?
1
vote
1answer
385 views

CRC error when extracting to SSD from 2nd HDD

I have a large RAR file (split up) containing an ISO on my 2nd HDD When I extract it: to the same HDD, it's OK to the system/OS SSD, I get CRC errors I've checked memory, run memtests, checked ...
1
vote
2answers
860 views

What is more important when extracting rars cpu or hdd?

When i am extracting big rars it takes forever. However when i look in the task man cpu usage is only about 16%. I am thinking that the hdd is the bottleneck, or maybe not? The hdd is an average 7200 ...
2
votes
5answers
2k views

Too big a difference between Loud and Quiet when watching DVD's… constantly have to adjust volume

It is hard for me to find the right volume for my computer to watch my dvd's on because it seems like most reasonable volumes become overwhelming at the loudest parts of a movie and it is hard to even ...
3
votes
1answer
2k views

mp3 compression MPEG1 vs MPEG2

I'm using CDex for converting wav to mp3, and want to ask you guys what version to use; MPEG I has max of 320kbps MPEG II has max of 160kbps MPEG II.5 has max of 160kbps I'm looking for a better ...
13
votes
2answers
6k views

How does file compression work?

So, I realised today I take file compression for granted. The ability to bundle a few files together into one, and have it come out smaller than any of them, is something I just accept as a fact, but ...
16
votes
4answers
31k views

How to make 7-Zip faster

I normally use WinRAR over 7-Zip simply because it's faster and only a little less efficient with compression. I did a few tests on different filetypes and sizes comparing the 7-Zip and WinRAR default ...
0
votes
4answers
150 views

284 GiB of data, 217.4 GiB of space

I want to reinstall my OS, but I don't have the hard drive space to backup any more (I have a RAID 1 array, so I haven't done it for a while). In my /home I have 284.8 GiB of data, and I have a spare ...
0
votes
1answer
658 views

How to see compressed and actual size of files on a compressed drive?

I'm using Windows 7 and installed a hard disk. When I formatted it I checked the option to enable file compression. I copied some files onto the hard drive. How can I see things like the ...
2
votes
1answer
4k views

How to compress .pdfs in word 2007?

I am trying to send my cover letter and resume away but apparently it is too big to send through craigs list(my computer says the total size is 500kb) as it has a 600kb limit(so small should be at ...
12
votes
1answer
243 views

Three formats? Why?

I needed to download the Ruby Source recently from here and it says, "available in three formats" which are .tar.bz2, .tar.gz and .zip. Is there any reason that we need all three formats? At least on ...
2
votes
3answers
14k views

How can I remove the password protection from a RAR archive? [duplicate]

I have a directory in which there are lots of password protected .RAR files/archives. The passwords of these individual archives are known. I want to remove the password protection from all of them ...
1
vote
2answers
202 views

Looking for archive tool with very simple command line usage [closed]

OS: Windows XP Requirements: Support compress/uncompress zip format Like gzip can use the original file name as archive file name, so no need to specify archive file name. gzip target_folder, so ...
0
votes
1answer
817 views

use Windows file compression on removable drive

I have a USB drive formatted with NTFS. I would like to use "compress contents to save disk space" option, although it is greyed out. It works fine on the C: drive. Any suggestions?
1
vote
2answers
197 views

Files being uncompressed faster than physicaly allowed by hard drive?

I recently got my new computer at the university and it is blazing fast. However when I decompress certain types of files, the computer says I'm decompressing them at over 200MB/s, which is way faster ...
1
vote
2answers
1k views

How to 7za file without specify archive name

Say have an executable target.exe, is there any way to compress this file into target.zip without specify archive name(output name) by using 7zip command line?
0
votes
2answers
1k views

UPX and .NET executables

Can UPX (upx.sourceforge.net) compact .net executables/dlls ?
2
votes
1answer
242 views

Compress latest kernel with upx

I'm just curious, how to compress latest (2.6.32 at time of writing) kernel using UPX? It worked well for older kernels but now repacked with UPX kernel fails to boot, standard compression methods ...
5
votes
3answers
719 views

How can I remove empty paths from a zip file?

I have a zip file that contains a empty path, which I want to be rid of. How can I clear it, while maintaining the rest of the zip? When I open the item in winzip I cannot see the empty file, but ...
4
votes
1answer
364 views

How to see just content of ZIP/RAR etc withoud downloading?

How to see just content of ZIP/RAR etc without downloading? for example like this http://dev.novemberborn.net/sifr3/nightlies/
3
votes
4answers
246 views

Scripting compression (ZIP or TAR) to be done in chunks

I'm trying to find a utility or approach out there that will allow me to compress an entire directory into chunks. I know it's easy to specify, for example, that the archive files created should be ...
23
votes
6answers
26k views

Is it possible to open a self-extracting compressed Windows file on a Mac?

If I have a compressed file that's stored as a self-extracting archive for Windows, i.e., a .exe file, is it possible to convert it to a zip file that can be unzipped under OS X? Alternatively, is ...
5
votes
3answers
3k views

What file compression application is the most space-efficient?

I have a bunch of directories that I want to keep, but I also want to clear out storage on my drive. What is the most efficient (in terms of compression ratio) compression application? I don't care ...
1
vote
4answers
1k views

Performance Decline after compressing entire C: drive

Hey guys, i recently tried to improve performance in my laptop by compressing files on the c: drive... however due to my own negligence i compressed the entire c: drive and not just the my documents ...
6
votes
8answers
5k views

Winrar-like archive utility for OS X

I've been a Mac user for about 1.5 years and so far enjoyed the experience. But one thing I miss from other operating systems is the lack of compression/decompression utilities that follow the ...
3
votes
1answer
2k views

Compress old mail with Apple Mail

I have 14GB of email (close to 1 million messages) on my Mac that I want to take up less space while still being able to reference "archived" messages. I have a set of folders that are effectively ...
3
votes
4answers
635 views

How to avoid compressing compressed files

Most compression programs compress all files by default. But when archiving a folder containing already compressed files, there is no need to compress them a second time, such as archives, packed ...
5
votes
5answers
8k views

How to set Mac OS X's Default Compression Format?

Mac OS X uses zip as it's default compression format. It makes this conveniently available from the contextual menu (control-click/right-click). I'd like to adjust this default to bzip2. I can do ...
1
vote
2answers
1k views

selfextracting archive with 7zip via cmd.exe

I downloaded 7za.exe and did this to compress a file.exe: 7za.rar a -mx9 archive file.exe Now I want to create a selfextracting archive (.exe), so I tried this: 7za.rar a -mx9 -sfx archive ...
6
votes
3answers
26k views

How to extract a gpg file

I have a file that is compressed. I used a program to find out what kind of file it is and it says that it's a gpg file. How do you uncompress a gpg file?
1
vote
4answers
699 views

Finding out what a file is

I have a compressed file but I don't know what it's compressed with. The extension doesn't give any clue. How can I find out what it is?
1
vote
5answers
879 views

Is there a simple encrypting archiver which is just like WinZip except for the glaring security hole?

I find it quite annoying that WinZip (and 7-zip, etc) does not encrypt the file names in the archive, just the file contents. This is a glaring security hole as the file & folder names can ...
7
votes
6answers
2k views

Is there a free way to compress a PDF? [duplicate]

I have several PDFs that are quite large (one is 80+ MB). Is there a free way to compress that PDF to a smaller size?
13
votes
5answers
18k views

What is the quickest, easiest way to compress a mp3 file?

I would like to compress an mp3 file, and I see a lot of references when searching google, but it seems like by now someone must have found something easy and that is guaranteed to work. Compressing ...
0
votes
1answer
413 views

Compress and Upload vis SSH?

Is it possible to compress several folders and upload to another location (ftp) remotely? I've a GoDaddy account with SSH access, and I'd like to create a backup (zip all folders) and upload directly ...
1
vote
2answers
1k views

How are images stored within a PDF?

The are places that prefer PDF's for printing, and we've also been using PDF as a distributable format that "everyone can open". It's very easy on a mac to save as PDF (or go to "print" and save it ...
2
votes
1answer
931 views

how supercompressed iso files are working

I am recently seeing "Super Compressed" ISO files which have claimed to compress iso files to sizes < 15 mb, where the original file size is in 4GB+. How is it possible?
23
votes
5answers
15k views

How can I open a .7z file in Ubuntu?

How can I open a .7z file in Ubuntu?