Compression decreases the size of data.

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3
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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 ...
3
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0answers
48 views

Compressed file with a header containing all files within it, at the beginning of the file

I have noticed that most files resulting from a compression / archive process do not have a list of the files contained at the beginning of the resulting file, but rather at the end of it. For ...
2
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0answers
40 views

Zipping a text file with sha256 hashes seems too efficient

I have an ASCII-encoded text file where each line has the following structure: XYplorer nn.nn.nnnn [yyyy-mm-dd hh.mm.ss] [S256 S256].zip ↑↑ ↑↑ ↑↑↑↑ ↑↑↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑↑ ↑64× ↑64× so a ...
2
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0answers
86 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 ...
2
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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
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0answers
584 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] ...
2
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0answers
337 views

Pacmd dynamic range compression Ubuntu 14.04

I used the answer at the link below to successfully set Dynamic Range Compression on my Ubuntu media box running Ubuntu 14.04 (SteamOS session, so no Ubuntu desktop session available). Realtime sound ...
2
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0answers
381 views

Why do IPSec VPN Compression and Windows Remote Desktop not work together?

I just discovered a strange problem. I connect to a remote network via VPN. Within this VPN is a separate Microsoft Small Business Server (which does not provide the VPN, another device does this). So ...
2
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0answers
638 views

Gifsicle: How to set it to not overwrite the original GIF file if the resulting modified GIF file is larger than the original?

About Gifsicle: Gifsicle is a command-line tool for creating, editing, and getting information about GIF images and animations. One of its features is (from its website): Optimize your ...
2
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0answers
400 views

Does a smaller cluster size increase the ratio of NTFS compression?

I read that NTFS compression needs a partition formatted with an allocation unit size <= 4KB. Could a smaller cluster size of a partition give more compression and lessen wasted space? For ...
1
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0answers
12 views

Is there anyway to reduce bandwidth usage of Skype for business?

We use a lot of 'Skype for Business' (i.e. the new Microsoft Lync), that I use while consuming expensive roaming data. Was wondering, if there are options (similar to various VLC clients) that lead to ...
1
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0answers
35 views

What ffmpeg settings to get the best possible video resolution/framerate that my webcam is capable of?

I want to record the best possible video file (in terms of resolution/framerate/colors) from my webcam. Right now I am using this command: ffmpeg -f v4l2 -framerate 25 -video_size 640x480 -i ...
1
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0answers
29 views

Use avconv and image magick to convert video into reduced size gif

I'm using this answer to convert a video capture of a small section of my screen to a gif for a tutorial on a webapp. The problem is that the gif conversion increases the file size. avconv -i ...
1
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0answers
89 views

Does any linux disk format support transparent folder compression? (Like NTFS)

I feel like I could use transparent, seamless folder compression. One way to achieve this, I think, is to compress normally, and mount an archive with Nautillus. AFAIK. you can run programs from the ...
1
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0answers
45 views

How to get uncompressed content when using recursive wget?

i am downloading many single pages with all static content (js, css, imgs...) via wget recursive. It showed up, that served content, which was compressed (gzip), is stored by wget in compressed form. ...
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0answers
197 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 ...
1
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0answers
275 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 ...
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0answers
30 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 ...
1
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0answers
26 views

General-purpose program for RLE compression

We have to deal with very large columnar files with fixed-size data and lots of padding bytes coming from mainframe. I would like to evaluate different compression techniques and their impact on ...
1
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0answers
180 views

Is there an alternative to httpfs2 to mount web urls in Linux?

Currently I use httpfs2 to mount direct web urls in the filesystem. For example a rar archive which has to be decompressed, but I don't have enough space on my VPS to download AND then decompress the ...
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0answers
35 views

Store disc images on a hard drive

I'm cleaning up around my computer (A Win7 ultimate machine), and part of my plan is to rip all my program CDs and store them on a dedicated 1TB hard drive. My initial plan was to simply dump the ...
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0answers
251 views

Improve slow NAS Ethernet transfer speeds: On-The-Fly Ethernet Compression with SAMBA?

Hardware: Pogoplug E02 (ARMv5te, Marvell Kirkwood 1.2GHz, 256m RAM) Software: ArchLinux, MDADM RAID 5 array, Ext4, SAMBA server This setup delivers file transfers to my Windows clients at ~21MB/s ...
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0answers
277 views

Compress 1 TB file collection into standalone archives each size no more than 2GB

I have about 1TB data stored in two drives and I need to compress and encrypt them into independent archives each size must be smaller than 2GB. Exception may be files that are larger than 2GB. Is ...
1
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0answers
834 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
73 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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0answers
81 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?
1
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0answers
500 views

Why does FFmpeg append blank black video to the end of my MP4 files when compressed from MOV?

I have several large MOV files that I want to compress to MP4. Unfortunately, when I use FFmpeg, it appends lots of black (blank) video at the end. (The destination file is longer than the source ...
1
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0answers
114 views

Re-zip archives with the compression level “No Compression”

I am running Windows 8.1 Enterprise x64. I have a folder containing hundreds of ZIP archives (aka Compressed folders). I need the fastest way to convert them (preferably, in-place) to vaild ZIP ...
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0answers
453 views

compressing video with ffmpeg while maintaining high frame rate

Update: I watched the output video on a different machine and it was fine. The issue must've been with the program I was using to watch the video. Nevermind. I'm trying to compress videos taken with ...
1
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0answers
608 views

Increased data usage on a VPN connection

I have been working on a remote computer over a VPN connection using Windows 7 Remote Desktop Connection. I RDP from my laptop (with non-HD display). Recently my wife has also been working from home ...
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0answers
199 views

How to make compact.exe to compress only folders, but not files?

I have a large and complex nested folder structure on disk. Say, Folder1 <many files> Subfolder1 <many files> Subfolder2 <many files> ... SubfolderNNN Compressing all ...
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0answers
399 views

Compressing files over the network with WINRAR - read error

I have 3.6 TB of backup files on a NAS that need to stay together (they are a full and a months worth of incrementals - the latter is only useful with the former) - but I need to move them off the NAS ...
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0answers
3k views

“extra bytes at beginning or within zipfile,” won't open file

I have an 8.3 gig zip containing tons of telescope observation data, but I can't extract no matter what I try. I've tried Archive Manager, unzip, and tried this guy's fix: ...
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0answers
1k views

How to verify 7zip'd files integrity

For some files I have compressed, I have been looking for a MD5 add-on to 7zip (As I have the MD5's by way of an Explorer Column Handler, in xplorer2); or a CRC Explorer Column Handler (Because 7Zip ...
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0answers
79 views

LZMA Based Archiving on Linux

I am trying to build an archiving system. I have tested out LZMA compression algorithm, and it provides very good results. However, I need the ability to add and retrieve(will remain in the archive) ...
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0answers
52 views

Archive / compression formats or tools which support multiple file forks or streams?

Lately I've become interested in the ability of several filesystems including Apple's HFS+ and Microsoft's NTFS which support two or more data streams. In Mac terminology these were most widely ...
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0answers
185 views

How to unpack a compressed executable without knowing the compression algorithm

I'm not sure if this question was asked. I searched for it and could not find it. How can I unpack a compressed executable without knowing what compression algorithm was used to compress it? For ...
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0answers
943 views

Set .png default compression in Photoshop CS6

Is there a possibility to set .png default compression options to "NONE / fast"? Whenever I try to save as .png, the default option is set to "smallest / slow".
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0answers
119 views

Extracting a tar file containing files with Chinese names will make the filenames illegible

On my Mac OS 10.6.8 I had a directory full of files that had Chinese filenames. I proceeded to run tar czf mydir.tar.gz mydir Now when I untar it with tar xzf mydir.tar.gz, the extracted filenames ...
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0answers
97 views

IIS vs httpZip (or other product) Compression

We're currently comparing httpZip compression software. Has anyone used this and can offer a comparison between that product and IIS? Is there a big savings for httpZip over IIS? If you aren't ...
1
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0answers
257 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 ...
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0answers
384 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, ...
0
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0answers
13 views

7zip is creating solid .zip files. Cannot add/remove/overwrite to .zip files ad-hoc

I'm using 7zip as an archive creation tool. .7z files may be created as solid or nonsolid files. .zip files are supposed to be inherently nonsolid. I have ~5GB of hierarchal folder/file structure ...
0
votes
0answers
20 views

How to extract PPmD archive data in Ubuntu?

So I have a file called ppmdData with no extension, then when I use the file command on it, it says it is a PPMD archive data. When I run 7z x secret, I get an unsupported method error. Can anyone ...
0
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0answers
26 views

Cut and Compress 4K Video?

I have a 20 second video which size in 4K which size is 125 MB. It is only about a defective electronic component so accuracy is not important. I want it much smaller. I have these options in VLC ...
0
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0answers
13 views

Strategies To Reduce Compressed File Lookup Time With Pixz?

I have a PIXZ-compressed (level -9) tarball containing around 4000 files (ordered, like pages in a book): compressed size is ~670M. Currently I am programmatically accessing these files using the ...
0
votes
0answers
31 views

Missing all the options in the Send To menu

So I'm just trying to send a file to a compressed folder from Explorer. But for some reason the only option I have there is "Bluetooth device". Did some Googling, found a suggestion to check the ...
0
votes
0answers
102 views

System and compressed memory taking too much memory

I recently upgraded my windows 10 OS but having a new issue with this "System and compressed memory" its taking too much memory and i have never seen this types of process in my task manager its ...
0
votes
0answers
24 views

What's the default compression algorithm used by Windows's Compression tool?

I'm trying to find out some documentation which details out which compression algorithm (e.g. deflate, LZMA, BZip2) is used by Windows 10's Send to 'Compressed Folder' tool. Some people reported that ...
0
votes
0answers
15 views

How do I shrink the size of a Djvu file?

I'd like to upload on Wikimedia Commons a djvu file from the Internet Archive, but unfortunately its size is larger than 100 MB, so I cannot. I was thinking that I could derive a new file from it, ...