Questions tagged [compression]
Compression decreases the size of data.
1,027
questions
12
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2answers
3k views
Why does preset “veryfast” in FFmpeg generate the most compressed file compared to all other presets?
The FFmpeg wiki says that the best compression rate is by preset "veryslow".
But when I am trying it with my video then preset veryfast provides the best compression in my case.
The following is the ...
0
votes
0answers
12 views
How to determine which files from C:\Windows\Installer\$PatchCache$\Managed can be removed?
Got an old 2008 R2 server where the C:\Windows\Installer\$PatchCache$\Managed is taking up 5 GB of the 92Gb available. I have been checking all the old threads but not really coming across a clear ...
1
vote
1answer
40 views
Very different compression rate with two similar files
I'm using WinRar to compress two text files, of approximately the same dimensions (80Mb), which contain a Json structured text.
The text is generated by the same program and, inspecting it, it seems ...
0
votes
0answers
53 views
After 7z unzip only the temp word doc is visible (which is corrupt), the original is missing
I have once sent myself a 7zip file when changing computers, when I tried to unzip it, only one of the word documents have seemed to be 'corrupt'. When I later investigated, I have realized that when ...
0
votes
1answer
28 views
NAS Compression/Decompression
I'm interested in building a NAS to act as a file server for a small number of people (myself being the sole user the majority of the time). I'm thinking the server would run on linux and serve files ...
0
votes
1answer
33 views
Linux - compress specific files while preserving path and folder structure
So, basically I'd like to do this: Compress only specific files from a folder while preserving folder structure but instead of Windows and 7Z, do it on a Linux and with native Linux tools (no root ...
2
votes
1answer
74 views
unzip many files with different passwords and compression formats with bash script
I have this bash script to unzip files with different passwords. But it decompresses indefinitely and damages the decompressed files
PASS="passfoo passbar passfoobar"
LIST=$(ls -1 *.{zip,7z,7z.001,...
1
vote
0answers
44 views
When compressing a large amount of files, 7zip stops while only returning “Killed”
Recently a computer of mine died and I'm trying to recover the files (650GB approximately) using a live ubuntu usb to compress the files and then move them to an external HDD. I don't just want to ...
1
vote
1answer
74 views
How to set low priority while compressing with wzzip.exe
I have this in batch and the code works without start /low. While compressing with wzzip the CPU is 100% and all other programs hang.
So to fix this issue I've been trying to either set affinity or ...
0
votes
2answers
63 views
Best compression method for 200gb fixed .vhd
I have a clone of my laptop's hdd saved in the ".vhd" format, as I am going to install the
Windows 20H1 Insider release from .iso soon. I have saved it in the fixed format at 200gb exactly through ...
1
vote
1answer
53 views
What file format to use for photos? I will edit them. Then I will add text and make a PDF
I want to shoot a few photos using the smartphone. I will receive JPEG files. Next step I will move this photos to desktop computer (Windows 10 Home 64-bit). Now I want to edit this photos: some of ...
0
votes
1answer
54 views
FFMPEG, resize, watermark and compress a video
I can't quite combine a couple of commands in FFMPEG.
I'm trying to
Burn in an external subtitle file
map all other streams since the file contains many audio and subtitle tracks i don't wish to ...
1
vote
1answer
55 views
Why does write speed constantly slow down in 7zip during compression?
Related Question:
Why does 7-Zip's compression speed lower over time?
So I am compressing files (particulatarly large files, ā„1GB). So I notice that the write speed is slowing down and the ...
0
votes
0answers
9 views
Recursively zip files, exclude the folders, but use the folder names for zip naming
I'm looking for a method to script 7zip to zip a bunch of folders in a parent dir, however I want the zips to exclude the folders, and only zip the folder contents. I do however want to use the folder ...
0
votes
2answers
87 views
How can you decompress a videofile in ffmpeg?
Example 1:
ffmpeg -i input.avi -c:v libxvid output.mp4
The code that I get as output is:
ffmpeg -i input_1.avi -c:v libxvid output_1.mp4
ffmpeg version git-2020-02-16-8578433 Copyright (c) 2000-2020 ...
0
votes
0answers
30 views
How to find the size of the compressed image?
So, if I have an image in BMP file format being 1024 x 768 and 8 bits (bit depth), I can get the size of the image: 1024 x 768 x 8 = 6,291,456; 6,291,456 / 8 x 1024 = 768 Kb, which is correct when I ...
0
votes
1answer
38 views
How to conditionally strip/compress binaries with alternate utilities (i. e. other than strip)
In our yocto-based embedded application, we now have several Golang binaries, which can become very large. For example, docker (from meta-virtualization) and related binaries weigh in with several 100 ...
0
votes
0answers
41 views
Reducing size of pdf generated from large docx file?
I have a manuscript for my book that is approximately 600Mb that my publisher requires be in a PDF with a minimum resolution of 300dpi with all fonts embedded and a maximum file size of 1.5Gb.
When ...
0
votes
1answer
46 views
What's happening when I create a file in a “NTFS compressed” directory?
What's exactly happening? The files appear in the UI as compressed. Is it?
If so, is it written twice (like, uncompressed version of the new files is stored, as a buffer, and compressed then (so ...
0
votes
1answer
27 views
Extract multipart rar with password, deleting parts as they are extracted
how can I use this on rar with password? I know the password is
https://superuser.com/a/1031807/1136215
0
votes
0answers
30 views
Create “Add to filename.rar” shortcut on Windows10 using AHK
I have a really simple problem which I haven't been able to find the right simple answer to. I'm working with a lot of folders. I want to improve my work speed.
After selecting a folder that I need ...
0
votes
0answers
39 views
Binary copy of Windows compressed/compacted files to a different location
Windows 10 now have these new algorithms for compact files, which is indeed improved in many ways comparing to the old NTFS build-in compression options. However they are not as 'transparent' as the ...
0
votes
1answer
64 views
Is it possible to compress alpha and RGB channels of PNG sequence separately with FFmpeg?
Suppose I have a sequence of 32-bit (RGBa) PNG files. Is it possible to compress the RGB channel with one codec and the alpha channel with another? For example, if I had the RGB and alpha as separate ...
0
votes
0answers
43 views
“Smart” fast compression for archiving mixed content?
I would like to backup a computer folder quickly to an archive format (e.g. tar, zip, 7z, gz, etc.). The folder contains many files:
Some are text files that can achieve a good compression ratio. ...
0
votes
1answer
86 views
How to make Dovecot maildir format emails be gziped using zlib
I activate compression plugin by set following on Dovecot:
# /etc/dovecot/conf.d/20-imap.conf
(...)
protocol imap {
mail_plugins = $mail_plugins zlib
}
# /etc/dovecot/conf.d/90-plugin.conf
(...)
...
1
vote
0answers
37 views
File compressor with recovery [closed]
I want to compress a lot of files with a file compressor. I've found that 7z is really good at this stuff, but the problem is that it doesn't add CRC recovery to the file to prevent corrumption in the ...
1
vote
1answer
358 views
Compressing Grayscale 8-bit PNG Sequences with ffmpeg
I typically deal with many high-resolution PNG sequences, many of which are RGB (24-bit) or entirely grayscale (8-bit). Because adjacent frames in the sequences are very similar, it is important that ...
0
votes
0answers
8 views
How create Makeself self executable archive file in LINUX? What is the steps to create Makeself self executable file in any Operating System? [duplicate]
I want to create a self-executable archive using Makeself.
I referred to makeself.io but didn't understand anything from it.
What are the steps for making a Makeself self-executable archive?
If I run ...
0
votes
0answers
11 views
Update WinRar archive splited by parts
I have many big csv files with data that I'm collecting in realtime.
I want to add new files to archive monthly.
What I did before - adding new csv file to big archive and do repack (and after upload ...
0
votes
1answer
94 views
How to extract original images from a lossless compressed video which is composed from a sequence of images?
I am trying to compress a sequence of images using h.264 with ffmpeg.
ffmpeg -f image2 -r 5 -i ori/binary%03d.jpg -vcodec libx264 -preset veryslow a.mp4
ffmpeg -i a.mp4 -q 2 rec/output_%03d.jpg
but ...
0
votes
1answer
33 views
Does 7z compression affected by CPU efficiency
I'm currently archiving a huge amount of data to 7zip, but i've a question regarding the result:
Given two processors: 1 very powerfull and the second low-cost
-or-
Given the same processor but 1 ...
0
votes
1answer
309 views
ffmpeg video compression: Desaturating colors / losing color information
I'm trying to compress some 4K videos (resolution: 3840x2160) that I've recorded with my Nexus 5X (running LineageOS).
My first attempt:
./ffmpeg -i VID_20190908_145514.mp4 -c:a copy -crf 23 -vf "...
2
votes
1answer
111 views
Do video containers affect video quality ? Or is it just the codec?
Do video or audio file containers (extensions) have any repercussion with the video in itself ? Or is the codec used the only thing that has a repercussion ?
For example I have the exact same video ...
0
votes
0answers
53 views
How do I access this hashed/compressed/encrypted backup data when I'm the owner?
I recently did a backup of my xperia phone onto my computer using the Xperia Companion Application.
I checked to backup apps and media in the procedure.
After everything finished, I looked at the ...
0
votes
0answers
77 views
OPNsense, OpenVPN to Yeastar PBX: Error - Bad LZO decompression header byte: 42
I'm pretty new to OPNsense and VPN's.
I have OPNsense set up on a virtual machine and I'm using it to access multiple Yeastar PBX's. I access some the PBX's fine but the there are some that I'm having ...
-1
votes
1answer
39 views
Windows compresses folder without asking where to put it
When I right-click on a folder I want to compress, then right-click > Send To > Compressed (zipped) Folder, it just starts compressing. It doesn't go through the normal process of asking me what the ...
0
votes
0answers
284 views
How do I compress many files into independently working WinRAR files?
I want to upload a vast amount of small files to a website. To make that process faster, I compressed them to a .rar file.
The problem: Such a large file can't be uploaded to that website. That's why ...
2
votes
0answers
55 views
Compressing many similar small binary files independently using a preset dictionary
I have to compress many similar small binary packets (about 1.5āÆKB a packet) for data transmission. IĀ tested .xz format on a 306āÆMB sample and I got 50% compression ratio (compressed to 153āÆMB). But ...
0
votes
1answer
124 views
Compress multiple folders with Winrar command line and batch
I want to compress all the folders that contain the word (Album), these folders have the following structure
Michael Jackson\Invincible (Album)
Michael Jackson\Thriller (Album)
Luciano Pavarotti\'O ...
0
votes
0answers
115 views
Is 15 million page faults usuall for the process Memory Compression?
I have a windows 10 PC with 8GB of ram, an AMD Ryzen 5 (3.2Ghz) and a GTX 1050 Ti. It will run very smooth when I am not doing things but struggles whenever I try and do a lot of multitasking, despite ...
1
vote
3answers
70 views
Is there a disk image file format that only store sectors which are filled (non empty)?
I have a 500GB hard drive that contains several NTFS partitions.
I would like to create a single disk image of all partitions. My ultimate goal is to mount that drive later and scan it for possible ...
0
votes
0answers
52 views
How can I get the Compy Data Compression proxy to work?
I tried to set up a Compy with HTTPS and MitM support, and I connected my iPhone to it but I keep getting these two errors whenever I try to load a page. I don't understand what I did wrong but i'm ...
0
votes
1answer
38 views
constantly trying to compress filesystem
is there a filesystem that constantly looks for ways to compress data using a small amount of processing power?
particularly i'm looking for a way to dedupe files within various archives (.bz2, 7z, ....
33
votes
1answer
4k views
7-Zip seems unable to compress zero-filled virtual disk image after 1.8 GB
I am trying to compress a virtual disk image that is mostly empty. It has about 2 GB used out of 13.5, but even after zero filling the empty space, I am still only able to compress it to around ...
0
votes
1answer
37 views
How to get 7z parameters values
I've found that the (undocumented) 7z -mx4 option gives the best time/compression ratio for my files:
7z a -r -mx4 outfile.7z infile.dat
Now I'd like to fine tune the parameters to get even better ...
0
votes
0answers
41 views
Is it possible to open a file with Windows compressed-folders ability without it having a .zip extension?
In Windows (10), is it possible to open a file without a .zip extension using Windows native compressed-folder ability?
I occasionally have apps I need to append a .zip extension onto in order to ...
0
votes
1answer
56 views
How to achieve better compression ratio in 7z format with HEVC files
I use an open source compression software named Peazip running on a Intel Core i5-8250U @1.6 GHz processor. However, I have tried compressing files to 7z many times but the compression ratio is hardly ...
0
votes
3answers
70 views
Is there a way to estimate how much space a file or directory of a given size will take up after being compressed with tar and bzip2?
Due to an imminent distro switch, I would like to backup my home directory. However, my home directory is 29 gigabytes. I would like to know how much space this would take up after being compressed ...
-2
votes
1answer
41 views
What software is used here to compress jpeg?
https://compressjpeg.com/
The copression level is pretty inpressive, and I would like to use that encoder (or something similar) offline.
2
votes
1answer
489 views
Unusual behaviour with a passworded rar being invalid password in winrar but falsely accepted in 7zip
I found an old .rar file on my computer but I couldn't remember the password exactly. I had a rough idea of what it was, so I wrote a program using 7ziplib in c# to brute force a bunch of permutations....
