Compression decreases the size of data.

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0
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1answer
108 views

“recompress” a 7z archive inline

I have a rather large (~500GB) 7-zip archive. I originally made it when I had more space available, and did so at rather fast, low-compression settings. Now things are tight, and I'd like to try and ...
2
votes
1answer
885 views

What's the quickest way to a minify a SQL file from the command line?

I want to run a single batch command that must take mySQLfile.sql and compress it by minifying it. Any suggestions on how to get mysqldump to produce the most compressed SQL file? It would be cool if ...
2
votes
1answer
93 views

NTFS compression ate all disk space with no possibility to recover

To increase available space on a HDD (Windows Server 2012 Standard x64), I tried to enable NTFS compression on that drive. While doing the compression, it ran out of available space (despite having ...
0
votes
1answer
51 views

How to search for a file that is compressed on a external drive from my mac?

My hard drive was from my Mac. I replaced it with a new hard drive. I was able to dump all the data from the damaged drive onto an external drive. The dump separated some of the files into Word docs, ...
0
votes
1answer
37 views

GPG with tar.gz at the same time without the full path being packed

I would like to compress and encrypt a folder: tar -cz "/path/to/the/folder/" | gpg --encrypt --passphrase "password" --recipient "mail@mail.mail" > "/destination/package.tar.gz.gpg" When I ...
6
votes
4answers
14k views

How to compress a file in UNIX?

I want to do an ordinary "zip", so my CW3 file becomes CW3.zip. I have tried to use some example commands found on the internet but they don't seem to work. I have tried the following, resulting in ...
1
vote
1answer
553 views

FFMPEG / libx264: How to specify a variable frame rate but with a maximum?

Instead of providing a fixed frame rate to FFMPEG/libx264 (-r/-framerate), I would like to specify a variable frame rate with a MAXIMUM value, and allow libx264 to down the frame rate as it sees fit. ...
8
votes
2answers
21k 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.
0
votes
1answer
132 views

7zip: compress and copy to destination folder

I am trying to do the following: command line compress a file from C:\TestFolder\file.txt (source location) and on the same command or bat file put that compressed file in (a destination folder) ...
24
votes
3answers
46k views

Is it possible to execute a file after extraction from a 7-Zip self-extracting archive (SFX) archive?

I'm try to make a compressed deploy-able application. Currently I'm taking a set of files that I've published from my IDE (Visual Studio 2008 - WPF published application) and compressing ...
2
votes
2answers
4k views

How do I compress multiple files into one archive using lzma?

Looking at the options of xz and lzma, I can't for the life of me figure out how to compress multiple files into one archive. I know it is possible because I've uncompressed a .lzma file and it opened ...
8
votes
1answer
3k views

How do I use Google data compression proxy on Firefox?

I am using GNU Icecat (GNU version of Mozilla Firefox) on Trisquel GNU/Linux. In order to minimize/optimize data usage while web surfing, I want to use google data compression proxy. So, How do I use ...
2
votes
2answers
836 views

Bloated Excel file

Someone send me an Excel file that's 10MB, and thus causes us email problems. When .zip'ed it goes to under 1MB, so presumably there's something wrong with the Excel sheet but is there any way to ...
-3
votes
1answer
125 views

Why youtube compression algorithm doesn't work well for Minecraft videos?

Minecraft videos have very small entropy : I can play hours to minecraft online exchanging only tens or hundred MB of data with the server, this is an entropy upper bound for Minecraft videos. ...
-1
votes
1answer
138 views

How can i compressed(winrar) a file using command prompt and the file name of the .rar is the same with the file

i have a autoback.bat file that will automatically backup my database and compress in using winrar application. the problem is i cannot create a rar file that is the same filename of my database. for ...
0
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0answers
37 views

LAME doesn't compress MP3 anymore

(I'm running Ubuntu 14.04) Until a while ago the following command used to work fine for compressing MP3 files: find . -iname '*.mp3' -exec sh -c 'lame -b 160 "$0" "$0"-160 && mv "$0"-160 ...
2
votes
0answers
87 views

Disable memory compression in Mac OS X for specific application?

Is there any way to disable the memory compression in Mac OS X for a specific application? I read how to disable it in general at Disable compressed memory in Mac OS 10.9 Mavericks? , but in my case ...
0
votes
1answer
28 views

How to compress an encrypted partition or drive in Windows?

Could someone let me know is there any effective way to compress an encrypted drive or partition in Windows to reduce its size ? Thanks
0
votes
1answer
265 views

What happened to .gzip option in 7-zip?

I am not sure if this is just a coincident or not but I have recently upgraded my OS to Win 10. I noticed only now (after the upgrade) that the .gzip archive format is not available in 7-zip ...
0
votes
2answers
83 views

To open lrzip-compressed in Debian 8.1

I downloaded the SageMath jessie package here but I cannot open it. I get the warning in ArchiveManager Could not open this file type There is no command installed for Tar archive (lrzip-compressed) ...
3
votes
0answers
123 views

Possible bug in 7zip - empty folders extract as empty files

I have a directory structure as follows: Main | |--empty_folder | |--folder | |--example.txt I'm zipping it using the .NET ZipFile.CreateFromDirectory method (but I doubt this has anything to ...
0
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0answers
38 views

How to change context menu option for 7zip?

I work a lot with .gzip format and I am wondering if there is a way to change the default "Add to" format in the context from .zip to .gzip.
1
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1answer
57 views

how to achieve same compression in linux and windows

I have a example.jar file. I'm trying update a class file in the jar. when I'm packing the class file using jar or zip utility(command line-linux) I tried : jar uf my MyJarFile.jar ...
0
votes
0answers
24 views

Why am I encountering 'Error decoding stream footer' when decompressing using `pixz`?

I compressed a file using tar -pcv input_dir | pixz 8 -p8 > output.tar.xz. When I try to decompress or list the files using pixz -d and pixz -l i encounter the error Error decoding stream footer. ...
0
votes
1answer
20 views

decompress multiples pdf files without using tmp files?

I have more than 100.000 pdf files I want to decompress it, then recompress theme all in one archive file to save space. all i found is: ls | xargs -P 4 -n 1 -I {} qpdf --stream-data=uncompress {} ...
19
votes
2answers
14k views

Is zip's encryption really bad?

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 ...
2
votes
1answer
294 views

Batch command to archive folders with content using WinRaR

I have lot of folders in the root "C:\Test\Archiv\" (more than 1000). To be more specific, I get one every hour. They are named as following : ay %year% m %month% d %day% h%hour% In each folders are ...
1
vote
1answer
56 views

rar - command line switch for exclude compress but store?

Assuming I have few files like : --- +Royi | +---1.txt +---2.txt +---3.Avi +---4.mp4 +---5.docx looking at : rar a -r -m1 Royi myArchive.rar This will shrink all ...
0
votes
0answers
77 views

Why is none of my Mac memory compressed?

I am constantly up against the 16GB physical memory barrier on my mac. I have looked in Activity Monitor and ZERO memory is compressed. I would like to have OS/X be aggressive in compressing - how ...
10
votes
5answers
11k views

Mac OS X not reporting directory sizes correctly?

In Finder, I've noticed that if I duplicate some .app files (in the Applications folder), Finder will show that the duplicate .app file is not the same size as the original. This file size ...
2
votes
1answer
537 views

Compress large CSV FIle? (500MB)

I have a CSV-File which is 500MB of size. I am searching for a way to compress is to it smallest possible size. I actually received the file back then in a ZIP-Folder which was only about 50MB of ...
2
votes
1answer
84 views

Why does 7-Zip's compression speed lower over time?

I'm busy backing up my local server files, which amounts to just under 4GB of data in ~295000 files. I selected 7z as the format, and set the level to Store. The process started pretty quickly, but ...
0
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0answers
112 views

What are all parameters to get the highest compression ratio for animation from ffmpeg x265?

Ok. I'll use -crf 51 (-crf 61, -crf 10 or any other), -preset placebo, -keyint=-1 (only one keyframe in the start). -allow-non-conformance (I am not sure if this is work with libx265). -ref 16, ...
0
votes
1answer
82 views

How do I zip files with the same name?

I'm on a Mac OS X 10.10.4 I need this: Detecting files with the same name, but different extension. (aaa.ai, aaa.eps, aaa.pdf and bbb.ai, bbb,eps, bbb.pdf and so on) Compressing those with the same ...
41
votes
4answers
22k views

How does NTFS compression affect performance?

I've heard that NTFS compression can reduce performance due to extra CPU usage, but I've read reports that it may actually increase performance because of reduced disk reads. How exactly does NTFS ...
15
votes
6answers
15k views

.tar files without directory structure

I'm .taring some files with the path example/super_user/Output.*. The resulting .tar looks like this: + example + super_user - Output.zip - Output.xml - Output.txt ...
0
votes
1answer
66 views

Which level of compression should I use a .iso file [duplicate]

I have a .iso file on my hard drive (on a windows 8 pc) and it is really big (something like 16 GB). I was trying to compress it (using 7-zip) so it could fit on a DVD-R. But when it finished ...
2
votes
2answers
164 views

How to compress extremely large file in place

I need to compress a 646.4GB file on a 1TB external HDD. This HDD currently has about 238.6GB free. However, since the straightforward compression methods create a new file, I'll not be able to ...
1
vote
1answer
6k views

7-Zip: Unsupported Compression Method while trying to extract a zipx file that consists of JPEGs

A zipx file I received consists of .csv files and .jpeg files. I used 7-zip to extract them. While the .csv files were sucessfully extracted, the JPEG files didn't. The error was something like this ...
0
votes
4answers
140 views

How to open tar gz file created using tar piped to gzip

I wanted to generate a tar gz file with the highest compression level, and I followed the solution from http://superuser.com/a/546509/461740: tar cv /path/to/directory | gzip -9 > file.tar.gz ...
0
votes
1answer
416 views

.zip corrupted on Mac

I've got a .zip file of approx. 20GB. (20,497,570,063 bytes) I am trying to uncompress it but both Archive Utility and Terminal are failing to do so. Archive Utility is giving error 2 (no such file ...
69
votes
7answers
23k 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 ...
0
votes
0answers
33 views

regex search compressed password protected files

I have a repository of a few million large text files. I need to regex search them on a regular basis. Because they are large, I use gzip to compress them and zgrep to search them. I have been asked ...
0
votes
0answers
210 views

How to recursively extract a zip bomb?

I downloaded the famous 42.zip zip bomb and was able to extract it in my computer without my system crashing. Then I realized that in order to see the effects of the bomb, I will need to recursively ...
2
votes
0answers
52 views

Unzip .gz file when line order is important

I am trying to unzip fastq.gz files and then analyze the sequencing data within them. However, later analysis is dependent on preservation of line (line 1 from zipped file must be line 1 in unzipped ...
2
votes
1answer
84 views

PNG or JPEG for an X-Ray without visible artifacts

A past paper question from a Multimedia Systems exam: If you had an X-Ray photograph of a leg which might be broken, which would give better compression before artifacts were visible, and which ...
0
votes
1answer
51 views

Unix gzip more than one file at once

I have come to the end of my research with unix:> I'm new with unix and its enviroment, so i need your help guys. Long story short, i have a housekeeping script, which runs daily/weekly (it doesnt ...
1
vote
1answer
471 views

“Compress contents to save disk space” option not available for one partition

One of the partitions on our Server 2003 R2 server recently ran out of free disk space. After freeing up a significant amount of free space (20 GB, which only corresponds to 1.37% of the partition - ...
0
votes
1answer
61 views

NTFS Compression on multiple folders

I have been tasked with compressing certain folders on a network drive. The drive is formatted NTFS on a Windows Server 2008 R2 machine. The folders to be backed up are all called "Backup", and are ...
0
votes
0answers
14 views

Will archiving little-used directories in my Dropbox folder increase the indexing speed?

I have 14336 files in my Dropbox directory. Many of these are in old projects that I don't touch any more, but that I like to keep around in case I need them. I know that Dropbox holds an index on ...