Compression decreases the size of data.

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25
votes
5answers
21k views

Compressing folders on a mac, without the .DS_Store

Is there anyway to get rid of the .DS_Store when compressing a folder on a mac? I work on a mac and send work to clients in zip format, but always get questioned on the .DS_Store folder inside them. ...
5
votes
2answers
144 views

Going sailing, bandwith $8/MB, plugging in ethernet uses 200kb of data to just start

Hey Everyone - I am going sailing for a year and have an INMARSAT FB150 which translates to about $8/MB for bandwidth "anywhere" on the ocean. I hope to only use about 50-60MB per month or less ...
0
votes
2answers
871 views

Looking for a program which uses LZW compression [closed]

I need to learn how to do Lempel–Ziv–Welch compression using pen and paper for my algorithms and data structures class. Unfortunately we have only a couple of examples in our book of how it is done. ...
0
votes
1answer
871 views

Determine compression ratio for Windows compressed drive

Is there a Windows 7 native way to display the overall compression ratio on a Windows compressed drive? As part of our disaster recovery process, we're copying some key system folders onto 2TB ...
0
votes
2answers
939 views

Does Windows XP has any compression program by default?

I would like to compress a database backup file on Windows. I wonder if Windows XP has by default any program (like WinZip) that I can use. If yes, where is it located ? If not, could you suggest a ...
1
vote
1answer
1k views

Tar xvzf question

Hi I use FC12 command : tar xvfz GeoIP.dat.gz I get the errors tar: This does not look like a tar archive tar: Skipping to next header tar: Error exit delayed from previous errors Whats the ...
1
vote
1answer
362 views

Batch AVI encoding (xVid/mp3)

I'm looking for some way to batch-encode Uncompressed AVI (with PCM audio) videos recorded with my digital camera. I've been using VirtualDub, but I can't find an automated/batch way to do it. I ...
2
votes
1answer
44 views

Download time of compressed and uncompressed files

Is there any difference in download time of a compressed file and an uncompressed file, both of same size? It may sound silly, but I haven't yet tried it and don't know if there is any difference.
9
votes
3answers
40k views

What settings to use when making 7zip files in order to get maximum compression when compressing PDFs?

What settings to use when making 7zip files in order to get maximum compression? I'm compressing PDF documents containing scanned images. I'm thinking about using LZMA2, but I don't know what to set ...
2
votes
2answers
4k views

gzip for 64-bit Windows

Does anyone know any version of Gzip which supports 64-bit Windows? I could not find anything.
2
votes
4answers
925 views

How resilient is the .7z file format?

I'm intended to package up quite a lot of data in to archives so that I can store them using an on-line file storage service and to various local backups - the intention being that this will be fairly ...
2
votes
2answers
2k views

Creating/extracting RAR files on Mac OS X

I would like to be able to create RAR files easily on Snow Leopard with some sort of GUI utility. I know that RARlabs maintains a Mac version of the RAR command line utility, but I don't want to have ...
1
vote
1answer
2k views

How to extract frames using ffmpeg?

I have a .avi file with me. How can I extract all the frames from it using ffmpeg?
3
votes
2answers
3k views

file permission in zip/7z/rar?

I want to package my application for linux, I use zip/tar.gz/7z/rar to do the compress in Windows. Because I do the compress in Windows, so when I extract the package in Linux, the file permission ...
5
votes
5answers
7k views

How do I convert a Linux disk image into a sparse file?

I have a bunch of disk images, made with ddrescue, on an EXT partition, and I want to reduce their size without losing data, while still being mountable. How can I fill the empty space in the image's ...
0
votes
2answers
81 views

How to determine total file space saved in a directory

I'm running on a Windows 7 computer and there is a directory that contains more than 10,000 compressed files (RAR, ZIP) with more added on a daily basis. Is there any application or script available ...
0
votes
2answers
474 views

How to update a TAR/Gzip archive

I have compressed a folder using tar like this: tar cvfz folder.tar.gz folder/ Now, say I have changed some of the files in that folder, added some and removed some. And now I want to update my ...
5
votes
3answers
547 views

Need to archive/encrypt 20GB of files

I have 20GB of creative files (flash/photoshop/illustrator) files that i need to ship to someone. Unfortunately, sending thru the internet isn't possible (proxy on both ends, unreliable connections, ...
1
vote
1answer
484 views

Automated backup to JungleDisk-RackSpace cloud

It's quite complicated. (Okay, not that much.) My father is a person who likes the old way, where you store stuff on DVD, BD, HDD. Sad thing that I can't afford a NAS, they just cost way too much. ...
0
votes
4answers
6k views

tar.gz won't extract on Mac OS X

Why is this not working? sh-3.2# tar -xzf postgresql-7.4.28.tar.gz gzip: stdin: not in gzip format tar: Child returned status 1 tar: Error exit delayed from previous errors
21
votes
6answers
50k views

Command to 'gzip' a folder?

I am new to Mac command prompt stuff. How do you create a gzip of a folder in Mac OS X? I was told by a few folks that if you want to create a gzip of a folder you should 'tar' it first and then ...
2
votes
2answers
2k views

Command line alternative to rar.exe with complex switches

I am searching for a command line alternative to rar.exe from winrar which supports the multitude of options that rar.exe does, preferably one that is open source. Specifically, I am searching for a ...
2
votes
2answers
259 views

A windows or linux program that can extract a THEOS compressed file

I have been searching all day for this and maybe someone here can help. I have a file that was compressed using THEOS's Compres command. Without access to a THEOS box and no login for their webisite ...
1
vote
0answers
246 views

Compress files on Windows Server 2003

Duplicate Questions How to compress files with batch file? Using compact.exe didn't do what I wanted. I'd like to have an archive file created so that the files can be retrieved. This is ...
3
votes
4answers
3k views

Windows: Will compressing the hard drive partition speed up disk access? [duplicate]

Possible Duplicate: How does NTFS compression affect performance? In theory, on a reasonably fast PC, the processor is mostly idle during hard drive access. A compressed file takes up less ...
9
votes
6answers
17k 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
762 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
181 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
17k 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
364 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, ...
23
votes
5answers
44k 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?
12
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
389 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
993 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 ...
4
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 ...
17
votes
4answers
35k 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
151 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
701 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
245 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
16k 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 ...