Compression decreases the size of data.

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Creating .xz with 7-Zip, claims insufficient memory (not true)

In WinXP 32bit with a Core i5 (dual core) and 4GB RAM, I'm trying to create an .xz archive from a 266MB log file using 7-Zip (GUI) on the "ultra" compression level (method: LZMA2, dictionary size: ...
3
votes
1answer
2k views

How can I deflate compressed streams inside a PDF?

I read a stackexchange post on how to find a stream of font data within a PDF. This stream, if decompressed properly, apparently creates a usable TTF file. But I'm not sure how to decompress it. ...
1
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1answer
85 views

Compressing images, which format to choose?

Might be a silly question, but I really don't know much about images formats. I have some family photos in my external hard drive but noticed they are really big and it's taking up space, is there any ...
2
votes
5answers
2k views

Compression software with slow rates, and very high compression

I have a lot of data that I don't have to 'get at right away', and I was wondering if there was any compression software I could use that could compress it down to a smaller size than I'm currently ...
1
vote
1answer
329 views

Would NTFS Compression actually speed up the use of USB flash drives?

When using NTFS on USB flash drives, would using NTFS compression make them faster? With fast processors and limited USB bit rate, it seems feasible that it might, and would also have the benefit ...
2
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2answers
759 views

NTFS Directory is encrypted AND compressed?

I was running EFSINFO on my WinXP SP3 machine today, trying to find any EFS-encrypted files on the system. Imagine my surprise when I discovered my C:\xampp\htdocs\ directory is both NTFS-compressed ...
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3answers
5k views

Do encrypted compression containers like ZIP and 7-Zip compress or encrypt first?

The discussion of "compress and then encrypt, or vice-versa" led me to ponder the following question: many compression containers, like ZIP, 7z, and rar support encrypting these containers. For ...
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1answer
194 views

Is it possible to add files to a compressed archive without repacking?

Or do I allways have to unpack, add new files, compress again?
68
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7answers
20k views

Compress and then encrypt, or vice-versa?

I am writing a VPN system which encrypts (AES256) its traffic across the net (Why write my own when there are 1,000,001 others already out there? Well, mine is a special one for a specific task that ...
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3answers
9k views

Is it a good idea to use compressed NTFS filesystem on an external harddisk?

I'm thinking about using compressed NTFS on my external USB harddisk. It should be used for backups only. Is it possible to access it from Linux? Is it reliable? According to Microsoft it's slower ...
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1answer
881 views

After Effects Export as JPEG sequence results in huge file

I have an After Effects project for school, and I've created a movie using JPEG sequences (10 @ ~100-200mb/each ). I have the output setting on the composition set to 640x480. I resized each JPEG ...
3
votes
2answers
5k views

Internet compression proxy for low speed broadband?

I live in a rural location, using high-latency wireless off a local ISP's tower. My speed tests vary day to day, but I can get around 1Mb up/down. The problem is, I work with large files, uploading ...
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1answer
1k views

Compressed disk image on Linux

I just got my new computer with a much bigger harddisk. I think I copied all important files over but just to be sure, I'd like to keep a disk image of my old disk. To save space, I'd like to compress ...
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3answers
4k views

How do I extract .7z files?

Or what do I do with them if not extract them?
1
vote
1answer
204 views

Is there anyway to compress a local html file?

I've got a program I've written that outputs a report in html format. This report can get very large (20-30Mb), and this tool can be run hundreds of times. To reduce disk usage, I'd like to compress ...
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5answers
765 views

software for compression-decompression of pictures

I need to send hundreds of pictures via email. The size is reaching 100s of MBs .. which is certainly burden on network. WinRar, 7-Zip aren't helping .. Would you like to suggest any software which ...
2
votes
1answer
276 views

Why is the NTFS compression setting ignored by some applications?

I use NTFS compression on some folders, I understand the pros and cons of this, but for my use case it is preferred. I have noticed some odd behavior for many years. Some applications do not "honor" ...
2
votes
4answers
17k views

How do I avoid my picture gets too blurry when compressed?

I have tried everything I can think of to avoid my page profile picture getting blurry , but no matter how small I resize it (resized it to width of 180px - still blurred), it still gets blurry. ...
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1answer
236 views

compressing pdf created by office 2007

So I am currently applying for jobs on my school's career website, and it has a limit of 200kb for resume's, cover letter, transcript etc. I have my resume (docx) and its in 31kb of size. However I ...
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4answers
5k views

Size comparison: wav versus MP3

How much space do I save with MP3 compression of audio compared to .wav files? In particular I'm looking for voice recordings, not so much music. Any benchmark data about this? Links?
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2answers
334 views

Is there a command line version of Windows XP's compression program

What is Windows XP's command line built in compression tool? I would like to call it from my batch file.
2
votes
2answers
450 views

7 zip archiving directory recursively

I zipped my old windows dir with 7 zip. It zipped the "Application Data" many time (hundreds) as shown here : C:\Windows.old\Application Data\Application Data\Application Data\Application ...
1
vote
1answer
665 views

Does iPhoto do lossless JPEG cropping?

If I crop a JPEG photo in iPhoto and then export it as JPEG, is the exported version re-compressed a second time, or does iPhoto somehow crop without re-encoding, thus avoiding further image ...
2
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1answer
597 views

are the contents of the Windows Recycle Bin compressed?

When things are in the Windows Recycle Bin (Windows Server 2003), are the contents compressed?
2
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1answer
2k views

Use ImageMagick to convert TIFF to PNGs, how to improve the speed?

I am using "convert" from IM to get PNGs from multi-page TIFF files, everything is good except the speed. From "convert" documentation, I found: For the MNG and PNG image formats, the quality ...
0
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1answer
627 views

Looking for a HDD tool that can perform deduplication and data compression

Hi experts and pros! And a happy new year 2011 to everyone! I'm looking for a "private" tool that could deduplicate my external HDD. I'm sure I have tons of files double on my Disk drives, and I ...
0
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1answer
2k views

Why does lossless video compression cause the file size to go way up?

I have a 200MB AVI that I'm trying to add hardsubs to. I'm using VirtualDub to do it. I selected the H264 lossless codec for compression. The resulting file is 800MB. Why does this happen? Is there a ...
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1answer
830 views

How to install x264 for use with ffdshow

x264 isn't showing in ffdshow. I downloaded x264.exe. What am I supposed to do with it so that x264 will show in ffdshow?
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4answers
3k views

How to hardcode subtitles into an AVI without loss of quality

I am using a program to hardcode subs into an AVI file. The problem is that is recompresses the video using a codec. I don't see why this is necessary and causes a noticeable loss of quality. Is there ...
0
votes
2answers
963 views

quicktime movie takes long time to load

I have a 49.1 mb quicktime movie file. It's embedded in some object/embed html tags. When page loads, I have it set to autoplay. Problem is it takes 16 seconds for the video to begin playing. I would ...
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2answers
10k views

Stuffit expander free on Mac OS 10.4.11

Just two questions: Does it exist? Which version of stuffit expander is surely working on this version of mac os x? I've been trying to download the 10.3 to 10.3.9 version from allume website but ...
2
votes
4answers
1k views

How to get 100% identical compressed files, for source files that only differ in creation date?

I want to be able to compress a file losslessly, and if the original file is identical to another user's file, I want both of our compressed files to match, even if the original file dates are ...
2
votes
1answer
2k views

Turn off compression images inside of a PDF with Ghostscript?

Is it possible to turn off or lower the compression of images inside a PDF with Ghostscript when I convert to jpg? I currently use the following: gs \ -dNOPAUSE \ -q \ -dBATCH \ -dSAFER \ ...
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1answer
9k views

ZIP file decompression inflating vs extracting

I used the cPanel control panel to extract image archive. While decompressing it displayed a list of all files with information like inflating filename... or extracting filename... I noticed that ...
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4answers
1k views

Compress pdf file? [duplicate]

I need to reduce the size or compress a PDF file. The PDF file is actually scanned images. Is there any way by which I can compress the file?
60
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5answers
32k views

Pros and cons of bzip vs gzip?

I've known gzip for years, recently I saw bzip being used at work. Are they basically equivalent, or are there significant pros and cons to one of them over the other?
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4answers
1k views

Browsable compressed filesystem archive with full attributes?

Maybe a variation of the whole question would be: Are there any other archiving tools than tar that preserve Linux file permissions and user/group flags? I want to create archives of a directory tree ...
0
votes
1answer
130 views

Is there a tool for verifying the contents of a Zip archive against the source directory's contents?

Here's the scenario: I create a ZIP archive using some GUI package like WinZip, 7-Zip or whatever by right-clicking on a directory "somename" and selecting "Compress to archive 'somename.zip'" When ...
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1answer
1k views

zip/tar/? files with depth parameter

I would like to zip files from a directory but only to a given depth. In the example below I would like to include files until a depth of 3: dir0/ dir1/ dir2 -> subdir1, subdir2 dir3 ...
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1answer
129 views

Backing up external drives

I have a WD 320GB external drive and a WD 1TB external drive. I would like to backup my 320GB on a regular basis. I have tried using the built in compressor in mac, but that fails saying unable to ...
3
votes
1answer
370 views

How is it that a file compression program can use up more RAM than the uncompressed file it is compressing?

I was compressing a 120 MB set of files on the best compression that 7z offers and noticed that it was consuming nearly 600MB of RAM at peak. Why do these compression programs use so much RAM even ...
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votes
5answers
24k 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
146 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
913 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
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1answer
932 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
953 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 ...
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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 ...
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1answer
374 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
46 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.
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3answers
42k 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 ...