Questions tagged [compression]
Compression decreases the size of data.
1,222
questions
0
votes
1
answer
7k
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 ...
- 199
8
votes
1
answer
3k
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 ...
- 3,294
2
votes
1
answer
3k
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 ...
- 23
5
votes
1
answer
10k
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 ...
- 310
1
vote
1
answer
975
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 ...
- 1,544
2
votes
1
answer
9k
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 ...
- 479
-1
votes
1
answer
96
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? ...
- 3,010
3
votes
3
answers
3k
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 ...
- 205
0
votes
1
answer
214
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 ...
- 163
1
vote
0
answers
502
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 document,...
- 7,918
2
votes
1
answer
164
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 ...
user404162
2
votes
0
answers
2k
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 -...
user432683
1
vote
0
answers
594
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 ...
- 11
2
votes
2
answers
508
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 ...
- 183
0
votes
1
answer
662
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
I ...
- 871
3
votes
1
answer
1k
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 ...
- 393
16
votes
1
answer
13k
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 ...
- 393
20
votes
2
answers
32k
views
Is it possible to compress a full file system on Linux?
On Windows I can use NTFS drive compression to save heaps of disk space; usually 30%, often much more. It also improves read and write speeds at the cost of higher CPU usage; which isn’t an argument ...
- 1,462
1
vote
1
answer
2k
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: ssl.use-...
- 251
0
votes
2
answers
862
views
What files can I safely enable NTFS compression for on Windows 7/8 USB bootable drive?
The title says it all. I am just a few MB short of copying the needed files to a USB flash drive I intend to use for installing Windows. I have marked the partition as active. I was wondering if I can ...
- 6,571
2
votes
1
answer
508
views
Does specifying the compression engine to tar directly actually use less intermediate disk space than tarring first and then compressing?
When I use tar to archive a directory and then compress it separately using e.g. xz, there will be a point where I have three files on my system - dir, dir.tar and dir.tar.xz. As soon as the ...
- 2,549
2
votes
1
answer
685
views
What is the most common archive file format to have mountable, readable/searchable archives?
I make periodic backups of my data, resulting in large chunks of files. Currently I copy them into different directories on a share on a NAS (plus an external HDD), indicating the date in the ...
- 508
1
vote
1
answer
1k
views
Disk space usage in large folders with over one million files
I have a NTFS-compressed folder containing one to two million small (~25KB) text files.
Recently, I noticed that far more space was being consumed than would be expected. Digging deeper revealed that ...
- 113
1
vote
1
answer
2k
views
dd , pv , gzip and exclude directory, possible?
Is it possible to do the following:
dd if=/dev/hdx | pv | gzip > /path/to/image.img\
--exclude=/temp --exclude=/lost+found --exclude=/proc --exclude=/path/to/image.img
So I want to make a backup ...
- 186
3
votes
2
answers
1k
views
How to tell of a GZip file is still being written while being copied
I am getting a gzip file in a path.
Input Folder Path:
<server>/input_gate
I want to check whether the GZIP file I am getting in this folder are valid?
I have used the following command. It ...
- 133
1
vote
2
answers
638
views
Why don't iPhone or iPad compress the video they record? [closed]
I just recorded 30mins of video on an iPad (1080p, of course) and it took up close to 5Gb. So my question: is it really so hard to do on-the-fly compression? Surely that's what those multi-core CPUs ...
- 382
0
votes
1
answer
2k
views
Should Windows 8 be taking up 40GB of my HDD when my drive is compressed?
I want to install a game that requires 12GB on my computer with an HDD that shows 53GB total capacity, so I cleared everything off of it.
All documents, pictures, downloads, desktop, etc empty
Drive ...
1
vote
1
answer
2k
views
restoring files after doing rsync with compression
I understand that you can rsync with arg -z and -a for compress and archive.
Can someone tell me with these options, does it affect the files being backed up in any way if ever they need to be ...
- 69
0
votes
1
answer
106
views
Why this scanned book image has no background?
If you save this image on your desktop, you see it's background color as your desktop color. If you open it with Adobe Photoshop, its background id checkered which means it has no background. It's ...
- 1,086
0
votes
2
answers
53
views
Should I archive old folders
I have many folders on my hard drives that contain many media files and logs for old websites I have created for clients that I rarely ever access now.
I want to know aside from compressing them what ...
- 425
9
votes
4
answers
40k
views
Uncompress bz2 file from command line on Windows
Is there any tool in the Windows command line that allows me to do this? Otherwise, is there any light and portable application that will allow me to?
Related question, can I rename .bz2 extension to ...
- 215
0
votes
1
answer
512
views
Does copying files via MTP over USB compress them?
I'm trying to backup my phone to a computer running Ubuntu 14.04 LTS, and I noticed that one of my backup images looked noticeably more pixelated, even when viewed at the same size as my phone screen.
...
- 101
6
votes
2
answers
8k
views
Is Gzip supposed to honor original filename during decompress?
This question stems from a Crypto++ library question on Stack Overflow: How to add filename to archive if compressing using Gzip class?.
Gzip, as specified in RFC 1952 has an optional field for the ...
- 12.1k
3
votes
1
answer
563
views
Samsung 850 Pro SSD compression
I intend on buying the Samsung 850 Pro SSD, to use as an external drive via USB and I am wondering if it uses any kind of compression, like SandForce based SSD drives? I am fairly obsessive about data ...
- 31
0
votes
4
answers
14k
views
How to automate Adobe Acrobat XI Standard to re-compress a lot of PDFs?
I've about 15 gigabyte of PDFs scanned with an old version of Adobe Acrobat that are huge.
Adobe Acrobat XI Standard that comes with my new scanner has an option to (it seems lossless) recompress ...
- 2,933
0
votes
1
answer
1k
views
How to batch compress sub subfolders?
I'm on Windows Server 2012 R2. I have a directory that looks like this:
Folder01
Subfolder 1
File1
File2
File3
Subfolder 2
File1
File2
Subfolder 3
...
- 157
1
vote
1
answer
2k
views
BTRFS filesystem, compression and copy on write
I'm planning about moving from etx4 to BTRFS filesystem on my pc and backup server.
I'm very interested in the BTRFS snapshot feature (I have understood it uses the copy on write feature) and the ...
- 243
1
vote
1
answer
1k
views
reducing the size of PDF file of scanned images
I downloaded this PDF file from a website which is 350 KB in size with 20 pages. All pages are scanned images. I extracted the images using Adobe Acrobat Pro which are 1.32 MB in size collectively (...
- 1,086
0
votes
1
answer
743
views
is it safe to compress the File History folder?
Is it safe to compress the File History folder in Windows 8? Mine has grown rather big and a lot of the files types would compress well. However, I dont see any information on compressing it.
It ...
- 73.3k
0
votes
3
answers
8k
views
Is there a way to compress folders individually using 7zip on a large collection of folders?
How can 260 folders be zipped individually using 7zip with a single command?
The person who originally asked this question voluntarily deleted the post. Since it was an interesting task, I ...
- 372
2
votes
0
answers
58
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 ...
- 121
3
votes
1
answer
4k
views
Best format for compression of large amount of small files
I tried to use .rar and I get a great rate of compression. However it take a lot of time to show the folder structure when I open the .rar file (tried different programs), it looks it is needed to ...
- 263
-2
votes
2
answers
290
views
7Zip Zipping up directories
I want to use 7 zip to compress and archive folders but I want it to exclude existing .7z files if they exist and not duplicate them with a .7z.7z ext. I found this but it duplicates the already ...
- 1
4
votes
1
answer
14k
views
How to dump and compress MySQL database in Windows only using command line
Is it possible to backup and compress just like in Linux:
mysqldump --all-databases | lzma > all.sql.gz
I only have smb:// and cmd.exe access via winexe, so no GUI (remote desktop is not enabled, ...
- 1,757
5
votes
6
answers
61k
views
How to reduce the size of windows OS Iso file?
I have an Iso file of windows 8.1 pro with December '14 updates. The problem is the file is too big to be burned on a normal 4.7GB DVD , its around 4.8. Now is it possible to remove a few updates so ...
- 302
175
votes
8
answers
60k
views
How is PNG lossless given that it has a compression parameter?
PNG files are said to use lossless compression. However, whenever I am in an image editor, such as GIMP and try to save an image as a PNG file, it asks for the compression parameter, which ranges ...
- 1,901
3
votes
1
answer
1k
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 ...
- 31
44
votes
1
answer
188k
views
Extracting a tar.gz file returns, “This does not look like a tar archive.”
I have a tar.gz file and I want to extract it using terminal. I used following commands: tar tvzf ldtp_3.5.0.orig.tar.gz and tar -xvzf ldtp_3.5.0.orig.tar.gz. However, I get the same result for both ...
0
votes
1
answer
148
views
Is it possible to perform Deduplication recursively?
If anybody is familiar with the concept of Deduplication (If not,read link on wikipedia)
http://en.wikipedia.org/wiki/Data_deduplication
Is it possible to perform Deduplication recursively i.e. ...
- 2,169
3
votes
4
answers
19k
views
Is it faster to compress files before copying? [duplicate]
I have around 80 GB of data I need copy to an external hard drive. Would it be faster to compress all the files first and then copy over? Or would the time it takes to compress and decompress take ...
- 149