Compression decreases the size of data.

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2answers
90 views

NTFS compressed folders: is it possible to tweak compression ratio?

As it seems, Windows compresses the NTFS compressed folders with the lowest compression ratio possible. While this maybe good for increasing speed and decreasing CPU load, for the files that are ...
7
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5answers
3k views

Whatever happened to compressed read/write filesystems?

Back in the 90s, my home computer was an Acorn Archimedes. It had on it a piece of software called ArcFS, which allowed you to create compressed archives, a bit like zip files. Unlike zip files, they ...
1
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2answers
246 views

Compressing multiple files into multiple archives?

I have a folder full of pdfs and I'm tired of Winraring each file separately. I don't want to put them all in one archive. Isn't there a command line I can use to make Winrar compress a file with ...
1
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4answers
17k views

Can I compress a RAR file again to reduce its size?

I had a 326 MB iso file that I compressed using WinRAR, with the best compression method. It got compressed to 144 MB. I want to compress more and want it to be limited to something around 22 MB. ...
2
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2answers
6k views

Untar a given linux tarball on MAC OS X

I have a Linux tarball that can't be unpacked. It gives me an unexpected error. I am told this is due to case insensitive on MAC OS X. How can I untar this file? tar -zxvf file.tar.gz ... x ...
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1answer
26 views

How do I back up images with limited disk space?

I'm in a scenario where I have one 500GB hard drive and about 400GB of images I want to tar. I obviously won't have enough disk space, but I don't mind getting rid of the images as they are added to ...
0
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0answers
35 views

Tape backup with compression

I would like to backup a NAS to a series of LT02 tapes, (200 gigs uncompressed, 400gigs compressed.) There are about 700 gigs of data to back up. I initially tried cpio, first trying to set hardware ...
0
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1answer
206 views

What is the difference between rar and RAR5 compression?

What is the difference between rar and RAR5 compression ? Which is better for which purpose vs the compression time.
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1answer
81 views

Recursively process zip archives to extract files while discarding specific format of files

On my Windows 7 machine, I have a directory full of downloaded dumps in ZIP archives. Each archive contains few text files, PDFs and rarely XML files. I want to extract all the contents of each ZIP ...
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4answers
5k views

How do I know the gzip compression level?

Given a gzip compressed file, how do I know what compression level (1-9) was used for it?
0
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0answers
17 views

How to have zpaq extract files to stdout

I have some log files compressed with ZPAQ that I do not want to extract to disk every time I need to go grep-ing for events. Would like to extact to stdout so I can handle the output the same way as ...
0
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2answers
38 views

I cannot open folders in .tar file

I've downloaded factory image for my Nexus4 mobile, the Image folder is compressed in .tar file but it tells me that its unknown file Type: File ,, how can i open it? here take some photo of my ...
2
votes
2answers
983 views

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: ...
0
votes
3answers
49 views

Zero sized tar.gz file found inside a tar.gz file

My current directory contains a single file like this- $ls -l -rw-r--r-- 1 root staff 8 May 28 09:10 pavan Now, I want to tar and gzip this file like $tar -cvf - * ...
0
votes
1answer
25 views

How can I compress a series of integers?

BARF2 (Better Archiver with Recursive Functionality) generates a huge barf2.count file, which is a number-only file. What's the best way to compress that?
2
votes
2answers
230 views

Compress an attachment in my mailclient inside my INBOX?

I got a lot of emails with uncompressed formats (like bmp, txt, ...) that I want to keep inside my IMAP-inbox, so I can access them from all my devices (Windows, Linux, ios, Android). Those emails ...
0
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0answers
80 views

Cannot complete the compressed folder extraction wizard

Recently my friend archived a folder in linux (Redhat) and uploaded in Google Drive. I have downloaded the .zip file and trying in it to unzip in windows 7. I am receiving following error: Cannot ...
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0answers
24 views

Why would my zipped file be the same size as the uncompressed files? [duplicate]

I am trying to zip 13 mp4s. The uncompressed versions of those files are 2.69GB. But when I zip them with 7zip, using Ultra compression level and any of the compression methods - including LZMA, the ...
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0answers
19 views

image drive with safecopy and compress the output

I am trying to image a drive with SafeCopy and compress the output file on the fly so that it won't take up way too much space. (aka 500GB > 50GB) Will this command work? sudo safecopy --stage1 ...
0
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3answers
137 views

How big is an 800x600 image file in PNG? [closed]

How big is an 800x600 image file supposed to be in PNG ? Actually what I would really like is a table that shows resolutions on the y-axis and formats/compression type on the x-axis. I ask this ...
2
votes
4answers
8k views

Compress a 1GB file into 200_MB?

So I just downloaded MySQL for Windows 64bit which 211.9MB but when I extracted it it is now 1.05GB. How did they do it? They archive wasn't damaged at all nor corrupted. Before (Compressed): ...
0
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1answer
39 views

Should I extract before running?

Is it not wise to run an executable from a zipped file without extracting first? Someone explained to me that there is no need to extract first. He explained that zipped files are nothing more than ...
0
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1answer
201 views

How to compress 14 GB of csv files with 7zip (minimizing space)?

I have to compress 14 GB of csv files with 7zip. What options should I use to achieve the highest compression? I have tried Ultra Level with both LZMA and PPMd compression method, obtaining results ...
0
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0answers
43 views

Fast way to forward an Outlook email as a zip

I need to find a quick way to select an email in Outlook 2010 and forward the email as a zip attachment. The recipient will always be the same. The subject and body of the email will always be the ...
1
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0answers
155 views

Difference between downscaling 1080p to 720p in real time and downscaling during encoding?

Suppose a high quality, uncompressed video is re-encoded twice, with almost identical encoding settings at a relatively low bitrate of 4mbps, but at different resolutions, first at 1080p, and then at ...
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0answers
31 views

Webm video flashes compression artefacts

Doing som testing on capturing video from VirtualBox for a screencasting project. VirtualBox uses webm for video and it works sort of OK. However, it has "flashes" of heavy compression artefacts. ...
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votes
2answers
75 views

Do web browsers download faster than your max bandwidth?

Since content is compressed on transmission and uncompressed on the browser, does that make the transfer rate faster than your bandwidth? Or is there another term for this? For example, a 1GB white ...
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 ...
5
votes
1answer
162 views

Change Excel Zip Compression Level in Windows

Excel compresses its files using Zip-Deflate and stores it. However, the compression level is far from the best. To reduce the size and send it across I have to unzip and re-zip it manually everytime. ...
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0answers
33 views

Sequential Compression of [Text] Files (7zip and Windows)

This is with Windows 7. I have an iterative process, and on each iteration it produces a text file. What I want to do is compress this text file on each iteration to an archive. I'm using vb.net and ...
7
votes
2answers
4k views

Multithreaded support in 7za

(I posted this first on serverfault, but then I realized it probably belongs here.) I'm trying compress a very large text file using 7za (p7zip) 9.20. The -mmt option doesn't seem to have any effect. ...
2
votes
2answers
101 views

Compressing compressed .tar.gz files deterministically

I want to perform a series of recompressions of compressed files to study their properties. At first, I tried simply recompressing .zip files in a loop: for f in $(seq 1 100) do zip $f.zip -9 -v ...
0
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1answer
18 views

Below what network speed should I be using compression for an rsync transfer?

I'm transferring some files from a remote server. The speeds for the transfer are abysmal (~1 MBps), and have got me thinking about optimizing the transfer for speed. At what network speed does it ...
9
votes
4answers
31k views

What are the best options to use when compressing files using 7 Zip?

I often have to gather log files and upload them to a central server (Owned by another company). The central server has a size limit of the file, so I am trying to create the smallest file possible ...
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0answers
119 views

Need to read a Windows 98 DRVSPACE.000 file in Windows 7

Today I came across a DRVSPACE.000 file in my archives and I want to recovers its contents. Beside the file is a READTHIS.TXT which reads: This disk was compressed using DriveSpace 3, which ...
0
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1answer
517 views

Does anyone know an effective method to ultra-compress files?

Does anyone know an effective method to ultra-compress files? You might have seen some PC games compressed to incredibly small sizes here and there (like GTA San Andreas which was compressed to 1mb ...
2
votes
0answers
283 views

tar: Cannot create symlink : File exists

I backup lots of gigebytes files in to myproject.tar.gz, and compress success without errors. Now, I want to decompress all to an folder "myprojects". adan@adan-Latitude-D630:~$ tar zxf ...
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0answers
28 views

Safe to convert OS in .uif to .iso?

I'm being sent Windows 7 in a .uif format. Is it okay to convert it to .iso so it can be installed from a USB? If so, what is the best way to do that?
0
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0answers
51 views

How can I list all files recursively that have the compressed attribute set?

I started a decompress operation using compact /U /S /I /Q > compact-report.txt on a large dir (120GB+, ~950M+ files) and it has been going on for about 24 hours now. Most files seem decompressed, ...
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0answers
36 views

Windows compact /s /u command runs forever on deep directories greater than MAX_PATH

I ran the command compact /U /S /I /Q > status.txt on a large deep directory and after it ran for over 24 hours I decided to investigate whether it was hanging. It turned out that meanwhile the ...
0
votes
1answer
36 views

Move data with compression

I'm using win 7.I have disk ~2Tb which one I want to format so I need to move data from it to other disk, but the problem is that I have not another 2Tb disk and I think I can compress data(on the ...
3
votes
6answers
3k views

Zip files without compression

I'd like to bundle a number of big files into a single file, to make them easier to share. The files are already compressed (eg. jpeg, video etc), so I don't need compression, only archiving. How can ...
0
votes
2answers
60 views

Do more compressed PNG images take longer to load?

When I create PNG files with very small disk size, I tend to wonder if the file size becomes less important than the time viewers would need to decompress the image. Technically that would be trivial ...
0
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0answers
94 views

New versions of srep failing my compression algorithm

I am currently using freearc, precomp042 and srep 3.2 (32bit) I am running on Windows 7 SP1 x64 with 8GB RAM I use 4 regular compressions styles as noted below depending on data type and have no ...
7
votes
4answers
2k views

Is there a compression or archiver program for Windows that also does deduplication?

I'm looking for an archiver program that can perform deduplication (dedupe) on the files being archived. Upon unpacking the archive, the software would put back any files it removed during the ...
0
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0answers
49 views

Change the default image compression in Photoshop Elements 11

I have a lot (200+) of jPegs that I need to crop and then save. I'm using Elements, so recording an Action is out. The approach I'm using is to edit a bunch of images, then Close All and use the ...
0
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1answer
138 views

Converting a scanned pdf to a compressed PDF with binary (2 level) image

I have many old scanned PDFs which take up too much space on disk. I have tried many PDF compressors available on the web. All of them ask me what compression to use for color images, and what to ...
2
votes
4answers
13k 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. ...
0
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2answers
73 views

Check if a compressed file is password protected before downloading

Everything is in the title: I'm aiming to download a big file, and I don't want to waste time downloading it because I don't know if it's password protected or not, especially with my slow internet ...
0
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2answers
3k views

What is more efficient / faster, rsync compression or ssh compression?

I currently rsync files: (i) locally and (ii) remotely over WAN (connection c. 8mbps down / 1.5mbps up). I am considering adding to rsync: -z to compress files. Or alternatively adding to ...