Compression decreases the size of data.

learn more… | top users | synonyms (1)

1
vote
1answer
3k 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 ...
1
vote
1answer
35 views

lighttpd complains about ssl.use-compression

I am trying to apply some of the tricks described here, and the problem is having ssl.use-compression = "disable" in lighttpd.conf, because server reports WARNING: unknown config-key: ...
0
votes
1answer
16 views

Decompress files in subfolders to the same subfolder using 7-Zip

I have a set of subfolders with .gz files buried in them. I need to decompress the files and keep the directory structure the same. I have used for /f "usebackq" %i in (`dir *.gz /s/b`) do 7za x %i ...
1
vote
2answers
3k views

7-zip command line -p switch not working according to help page

I want to be able to automate the encryption of the file type .pcapng in a windows batch script. My current problem is that I get an error when extracting the encrypted file saying something along the ...
97
votes
5answers
196k views

How to decompress a .bz2 file

I have a file as: filename.bz2, but I can't figure out how to decompress it. I tried several methods, none of them seems work. I have tried the command: tar xvjf filename.tar.bz2, but it didn't work ...
2
votes
2answers
29 views

Which lossless image codec can achieve the highest compression ratio on photographs of buildings?

I was wondering which lossless image codec is best for compressing photographs* if we only care about final file size? * scanned negativs specifically Additionally does it make a difference if the ...
1
vote
3answers
3k views

How to extract multipart rar with missing parts?

I have a multipart .rar archive containing a single .tar.gz file inside it (don't ask why, that is just how it was made). I am missing a few of the parts, but do have the first part. I would like to ...
0
votes
2answers
28 views
10
votes
4answers
5k views

How can I compress a file on Linux in-place, without using additional disk space?

I've got a 100GB drive that has a 95GB file. I need to free up some space on the drive (and right now transferring the file off the drive is not an option). The file would compress well with gzip or ...
1
vote
1answer
21 views

Excel conditional drop down lists causing massive file size

I have an excel file which relies heavily on data validation. There are about 20 drop down lists per row. One column has a 35 formatting conditions. One column is a conditional drop down list (using ...
64
votes
6answers
19k 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
1answer
23 views

How to recursively compress subdirectory's files with password

I need to recursively compress subdirectory's files with password and then delete the uncompressed file in bash file. There are zip files and other files. I don't want to compress zip files again. I ...
0
votes
1answer
25 views

Does unzipping a file on a remote server download the files back to my local?

I need to copy a high number of files to a remote windows server. I am connecting to it via VPN and then browsing to the remote folder in Windows Explorer. Problem is uploading is really slow, ...
0
votes
0answers
19 views

How to create a highly compress self extracting archive with 7zip or winrar?

I have downloaded a highly compressed call of duty modern warfare highly compressed 99 mb self extracting 7 zip archive .after extraction it becomes 6.35 gb how they compressed these things .i know ...
1
vote
1answer
35 views

I can't get compress.exe to produce anything

I'm trying to emulate the Windows Send to/Compressed (zipped) folder function using the Microsoft tool compress.exe, included as part of the Windows Server 2003 Resource Kit. It might not be possible ...
0
votes
1answer
31 views

Losing storage space on Windows 8.1 by compressing and decompressing the disk [duplicate]

At first I thought if I compress the disk, then I would get extra space. However, after doing the compression I lost 2.5GB. Then, I decompress the whole disk to regain the lost 2.5GB but I lost 1GB ...
-2
votes
0answers
16 views

What is diff. b/w IBM MXT (memory expansion technology) & AME (active memory expansion)

I saw two memory compression techniques from IBM, one is MXT (here) and another is AME (here and here). Can someone please tell if they are different and if so, what is the difference. Thanks.
1
vote
4answers
435 views

Does 7zip compression level affect decompression speed?

I have a directory that I would like to password protect and encrypt. I am using PeaZip to do this using 7zip compression. I'd like to use the 7z like a directory and hard drive space is not a ...
0
votes
0answers
63 views

True crypt container issue

I had created a true crypt container in my external HDD but stupidly ticked the "compress contents to save disk space" option from file properties. Now when I attempt to mount my container with true ...
2
votes
2answers
56 views

Container with in-built compression, which automatically adjust its size

I try to find an efficient way of rsyncing contents of an ext4 file system as a part of a regular backup, yet I consider a decent compression and a minimal required space. I can just use plain rsync ...
1
vote
1answer
31 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 ...
1
vote
3answers
29 views

Is it better to compress all data or compressed directories?

I'm archiving some projects, let's say each of them has own directory: projects |- project-1 |- project-2 |- project-3 I started compressing them as following: ==== SITUATION 1 ==== projects ...
0
votes
0answers
33 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. ...
2
votes
0answers
47 views

Uncompressing files, compact'ed on Windows 10

I'm testing Windows 10 and one very interesting thing I found is new switches for compact: Displays or alters the compression of files on NTFS partitions. COMPACT [/C | /U] [/S[:dir]] [/A] [/I] [/F] ...
0
votes
1answer
72 views

ffmpeg: Highest quality 50i to 50p conversion, comparable to Adobe Premiere

I have 50i footage (more specifically tagged as 25 fps but does contain movement on the secondary fields). I am able to get pretty good quality conversion to 50p from Adobe Premiere by simply ...
0
votes
0answers
23 views

“Size on disk” column missing in Windows Explorer?

I decided to use the "compress this drive to save space" option on my backup drive, which simply houses a Windows Server Backup. I learned that when viewing file properies for files on a drive using ...
2
votes
1answer
36 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 ...
2
votes
1answer
46 views

7zip - Command Line: how to set output path?

I want to compress all HTM files in D:\HTM\ to an archive called comp.7z which is created in D:\HTM\ directory, so I do the following: 7z a -o "D:\HTM" comp.7z "D:\HTM" and get an error, exactly as ...
1
vote
1answer
18 views

Winrar self extracting SFX fail to launch

I created an SFX file (to unzip and launch a program directly) with Winrar which is supposed to be installed in a TEMP folder. I specified to launch "bin/myprogram.exe" after extraction. When I ...
3
votes
2answers
259 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
votes
1answer
40 views

Winrar command line compression ratio

I have a Winrar command line that look like this: "c:\Program Files\WinRAR\WinRAR.exe" a -afrar -s -m5 "e:\output.rar" "e:\foldertozip" The folder that I am compress by default is 9.08MB. The ...
3
votes
2answers
736 views

How can I search for files that are either compressed or uncompressed in Windows Explorer?

I know that Windows explorer can colorize the NTFS compression state of a file, in both the regular and search views. How can I specifically filter/search for files that are compressed or ...
7
votes
5answers
19k views

What if I checked the box “Compress this drive to save disk space” on an SSD?

I was wondering how it would effect an SSD if this was checked: I was just curious whether it would save my SSD disk space?
3
votes
2answers
6k views

Batch resize and compress PDF files

I need a way to size down and compress batches of PDF files. I'd prefer to do this on Windows, but Linux would be fine if it meant a smoother workflow. I know that there's programs such as NitroPDF ...
-1
votes
1answer
35 views

How can compressed archives like .RAR be repaired?

I'm interested to know how WinRAR and 7-zip repairs archives but unfortunately I couldn't find any description about this process.So I'm here to ask: How does WinRAR or 7-zip repairing process work? ...
13
votes
4answers
20k 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
2answers
34 views

How to create a zip file with files in FAT format on Linux

I have to create a zip file (with no compression). I want the files in the zip to be in FAT format. That is, If i use zipinfo command, I should get the following: ... -rw-a-- 2.0 fat ...
0
votes
1answer
25 views

accessing files directly from SFX archive

Similar questions have been asked on this forum, but not identical, so I am sorry if this is a bit redundant. I have made a "portable" application. I used WINRar to create an SFX self-extracting ...
2
votes
1answer
63 views

Slight file content difference due to LZW compression

In order to test if LZW compression is truly lossless I did the following: I created a master uncompressed TIFF file. Created an LZW compressed version of it Saved that compressed TIFF back into an ...
0
votes
0answers
23 views

Why does performing OCR in Adobe create a much larger document?

I'm using Adobe Acrobat Pro XI on Macintosh OS X Yosemite and I've noticed that doing OCR sometimes creates a much larger document. For example, I scanned a four page document and got a 458K ...
0
votes
1answer
119 views

Difference between pixz and xz with -T option

I'm trying to compress a 100GB with a good ratio, so I decided to use xz. I don't need it to be very fast, but since I have an 8-threads CPU, I was wondering how to take advantage of them. I found ...
20
votes
2answers
34k 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 ...
0
votes
0answers
29 views

Stop Compression: Google Drive Videos?

Is it possible to stop the compression of Google Drive videos? I uploaded an 18.4MB video in mp4, that was already compressed, and google drive added further compression, resulting in a block effect ...
0
votes
2answers
59 views

Compressing a lot of similar JPEG images

I have a lot of—hundreds of thousands—JPEG images, and most of them are very similar to each other. While they aren’t of high quality and take about 100+ kB each, this adds up to a lot of storage. Are ...
0
votes
0answers
21 views

Set maximum size of zip/7z archive

I have multiple files that I would like to pack into archives of no more than 100MB. The only option I could find was to split the archive into volumes, but what I want is standalone archives that can ...
1
vote
2answers
2k views

Is there an rsync alternative, that stores compressed and encrypted?

I'm looking for a suitable off-site backup / file synchronization solution. Both local client and remote server run linux. Storage space on the server is limited, bandwidth between client and server ...
1
vote
0answers
20 views

wget only new or updated files when the source files are compressed but the destination files are uncompressed

I would like to know how to wget files from a url which are stored with bz2 compression. However, I would like to only wget the new and updated files, relative to my destination, where the files are ...
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 ...
4
votes
3answers
4k views

Any add-on(service) for firefox to compress incoming data like opera [closed]

I want to know if there is any service or add-on available for firefox to compress the incoming data like opera browser.
0
votes
1answer
18 views

Inflate multi-file zip files in linux

I just downloaded some zip files that were splited. (The dreamplug rootfs files to be precise). They are called rootfs_dreamplug_v10_Aug-28-20128.zip.001 rootfs_dreamplug_v10_Aug-28-20128.zip.002 ...