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Questions tagged [compression]

The re-encoding of a file or data into a form that uses fewer bits of information than the original data.

2
votes
2answers
201 views

APFS - how do I enable transparent compression

How do i enable transparent filesystem compression on any APFS volume? Or check if it is already enabled? I am expecting something similiar to NTFS compressed attribute. According to Wiki it should ...
1
vote
1answer
130 views

Compressed hidden files are not hidden anymore when uncompressing on Windows

When I zip hidden files and folder and unzip on a Windows PC, they do not remain hidden. I tried to hide them with dot and also with the command chflags hidden. Is there anything I can do? It happens ...
-2
votes
1answer
245 views

A script to shrink and compress DMG disk images does not seem to work well in my scenario

I'm trying to resize the *.dmg of my MAC OS X installation file because I have only DVD of 4.7 GB and not dual layer disks,at the moment. The problem is that the dmg file is almost 7 GB large and I ...
7
votes
3answers
3k views

Tell macOS to only use swap and compressed memory when really needed (macOS 10.14 Mojave)

As disabling swap and/or compressing memory is not recommended and also not a stable option after 10.9 Mavericks (despite the vm setting exists), I'm doomed after few days of running my Mac with my ...
1
vote
2answers
91 views

How to decompress and run .app?

I'm trying to execute an AppleScript .app thats compressed. unzip -p file.app.zip | open - or open < $(unzip -p file.app.zip) Is this possible?
2
votes
3answers
978 views

macOS equivalent to the Windows “Compress file/folder content on disk to save space” option

Windows has a useful feature where files can be transparently compressed/decompressed on the fly. This is activated by right-clicking on a File, directory or Disk, selecting Properties and then ...
2
votes
3answers
127 views

Is it okay to compress application files? (Especially licensed applications)

I have attempted to research this but given the fact that applications exist to compress other files, I've found it difficult to learn about compressing applications themselves. I presume its okay to ...
5
votes
3answers
4k views

Why do the photos on my iPhone 7 seem to be losing quality?

The photo quality is my iPhone 7 is very low. I found out that this may be because I switched on “iCloud Photo Library” a few months earlier, and “Optimize IPhone Store” was selected. Does doing so ...
-2
votes
1answer
138 views

How to reduce a PDF size in mac [duplicate]

How can I reduce a PDF size that is very big locally in a Mac
1
vote
1answer
690 views

How to unzip .xz

How can I unzip a .xz file? Archive utility failed. Is there an app that I should get to do it? (Mac Pro, OS X Yosemite 10.10.5)
1
vote
2answers
110 views

Compression / archival utility which stores the most metadata?

I recently did a backup of a FAT32 disk which contained a lot of diverse data. It contains many media files, many big binary files, and as usual with FAT32, it has all kinds of odd (but potentially ...
1
vote
1answer
725 views

Extract HFS+/HFSX volume from dmg file

Dmg file contains a volume with identifier Apple_HFS, which is compressed with various methods (zlib, bz2, etc.), how can I extract a raw, uncompressed HFS volume from DMG file? Right now, it cannot ...
0
votes
2answers
34 views

Compress attachments in received emails

I regularly receive emails with very large attachments (uncompressed scans, photos, videos, etc.). Obviously, the sender could have done me a favor by compressing the files before sharing. But not ...
46
votes
7answers
60k views

How can I unpack .7z files via MacOS terminal?

Looking to unpack a bunch of files.7z via terminal. Is there a command-line tool built in, available or I shall install an application that comes with a graphical interface?
2
votes
0answers
147 views

Can I turn off memory compression for one specific app?

I am using MATLAB on my Mac. Well, MATLAB is running well but not fast -- while there are plenty of free memory, my Mac still compresses MATLAB's memory - from ~2GB to ~600MB -- not to mention the ...
1
vote
2answers
267 views

compress Long size file into multiple limited size xz file

I have files of 28GB size. I want to compress using .xz LZMA, with .xz chuncks of 1G (1024MB) size files... MyFile.vdi -> MyFile00.xz, MyFile01.xz, MyFile02.xz... How do it in macOS? EDIT sh-3....
1
vote
1answer
41 views

Breaking pdf to various images, compress, and recombine

I want to save each page of a PDF file as separate image, compress them, and recombine back as PDF. Some PDF files I often use are strangely large in size. I mean, some 100 pages but some 200M. I ...
0
votes
1answer
2k views

compress jpeg images from terminal [duplicate]

I am looking for a way to compress jpeg images on a Mac from Terminal. Basically, a library like pngquant, except it is for jpeg format. Are you aware of a software that does that?
1
vote
0answers
36 views

What are those “._<filename>” files show in tar verbose output, but are not in the untarred directory? [duplicate]

Some hidden files appear in the verbose output of tar, but then do not exist in the directory where the tar output is deposited. I am surprised by this because I thought working in Terminal command ...
3
votes
2answers
1k views

How to compress iPhone QuickTime screen recording's file size?

I've recorded my iPhone screen through QuickTime on my MacBook and made several recordings already. Unfortunately, the resulting files are too large. They get saved in .MOV format, and 10 mins takes ...
8
votes
0answers
3k views

Can I turn off swap and/or memory compression on macOS 10.12, Sierra?

Is there a way with macOS 10.12, Sierra, to safely turn off compressed memory? And is there a way to turn off safely swap? This was possible on macOS 10.9 and macOS 10.10. Although it sometimes ...
3
votes
1answer
3k views

Create tar archive with xz compression?

I'd like to create a tarball using the xz compression tool. According to google, as of 10.10 there is an undocumented "--xz" switch for tar but I can't get it to work. On linux there is a "-J" switch ...
3
votes
4answers
3k views

How to extract an .ace compressed file?

Is there a way to open .ace compressed file on macOS? I tried searching for solutions but haven't come across any method to extract it yet.
1
vote
1answer
431 views

Multithreaded compression in xz on macos

Is it possible to use the multithreaded compression built into xz 5.2+ on macos? Currently using homebrew xz 5.2.3 on macos 10.12.3 with a hyperthreaded quadcore cpu and no matter my setting for ...
1
vote
2answers
428 views

Compress multiple files in different folders

Could someone help me with compressing thousands of files? I have a lot of folders and a lot of files in these folders, i would like to know if it's possible to compress each file separately. Foe ...
1
vote
1answer
36 views

How can I de-compress a source file on my basic MacBookAir (macOS Sierra Version 10.12.2)

I've downloaded the source file from https://arxiv.org/format/1610.01410v2 How can I decompress it to obtain the plain text (say, in a TextEdit file)? The file I downloaded is designated 1610....
2
votes
3answers
1k views

Terminal - Is the built in zip command lossy?

I'm using BASH in the terminal on Yosemite. Is the zip command lossy? I'm using it like this zip -er ./output.zip ./input -e encrypt -r recurse I am trying to avoid lossy compression when ...
1
vote
1answer
159 views

Preferred sources/methods for VirtualBox images on macOS 10.12?

I have a 2016 MacBook Pro running macOS 10.12 and I want to run a Linux VM such as Mint using VirtualBox. I am looking for best practices or official/recommended sources for an image that is packaged ...
1
vote
1answer
928 views

Why does .tar.gz automatically extract the GZip archive when I download it in Safari?

I downloaded a .tar.gz archive backup of a website. Every time I download it, when I click the magnifying glass in Safari Downloads, it takes me to the file, but it's now just a .tar, and so is ...
0
votes
1answer
96 views

How is the Compressed Mem column in Activity Monitor calculated?

Say we have something like Process Name Memory Compressed Mem Firefox 2.60 GB 1 GB What do the figures mean? Is it: 1GB is compressed and we don't know how much it's compressed by so ...
2
votes
1answer
321 views

Do Apple Lossless tracks remain lossless when sent via Airplay to a 4th gen Apple TV?

This question, from 2012, asks whether there is loss in the signal quality of an Apple-Lossless-encoded file when transmitted from a Macbook to an Airport Express. I am wondering whether things are ...
6
votes
2answers
702 views

Will Time Machine store the same data twice in this situation?

I had 80 GB of movies on my internal HDD. Time Machine backed them up to an external HDD, along with everything else on my drive. I then moved those movies to another external HDD (which is not being ...
1
vote
1answer
1k views

List number of files in multiple zip files

How can I get the total number of files in multiple zip files at the same time? I have around 1000 zipfiles in one folder and would like to know the total amount of files inside them all combined. How ...
7
votes
1answer
3k views

Large zip files created in OS X cannot be opened in Windows

When I compress a large directory in OS X, like 5-6 GB the resulting archive cannot be browsed in Windows / Total Commander. It hangs the app and stays at 100% cpu usage, like its trying to extract it ...
0
votes
3answers
207 views

Simple 'drag and drop style' video compressor

Is there any app really simple to compress videos on Mac? Something like JPEGmini for videos (do not resize, just reduce file size). I just know Handbrake, but it is not the most simple solution.
0
votes
1answer
536 views

Apple website images compression

Ok I searched like the whole internet for this topic but couldnt find ANYTHING at all and thought maybe this is the right place to ask such a question. I was recently visiting apples iphone site and ...
3
votes
1answer
4k views

Can SquashFS filesystems work with macOS El Capitan?

I am converting some .tar.gz to SquashFS (using squashfs from homebrew) using xz compression because I want to be able to mount the archives and read the content without extrating and also because the ...
0
votes
0answers
376 views

kernel: decmpfs repeated error messages origin?

I am in the process of evaluating different anti-virus on Mac OS X (Mountain Lion, Mavericks, Yosemite…). Upon running a full scan to test Sophos on a Mountain Lion Mac I witnessed a total slow down ...
0
votes
1answer
62 views

Why is this folder 4.2mb? It only has a handful of relatively small text files in it!

I have a WordPress plugin which was originally 26kb zipped (79kb uncompressed). I installed it, then made some live changes, then downloaded it and found that the plugin folder is showing 4.2MB in ...
1
vote
0answers
3k views

Does OSX 10.10.4 support LZMA compression at the individual file level (not tar files)?

From the command line, I would like to compress some database dumps using the LZMA algorithm. And, OSX adds XZ support (written in October of last year), claims " It turns out the XZ support in OS X ...
2
votes
0answers
93 views

Exponential PDF File Size in Preview

I have word document (.docx on a mac) at 3.4 MB. When I save it to PDF it becomes a whomping 90 MB. I can't make it smaller and I can't figure out why it's happening. Here are the details: I've tried ...
5
votes
1answer
1k views

How do I transparently compress a directory?

I'd like to enable HFS+ compression for a directory, applying it to both the existing files in that directory and newly copied files. I expect to be able to read and write the contents of that ...
6
votes
2answers
3k views

How to zip from terminal without creating folder structure of path to folder?

It is possible to zip a target folder with encryption by the terminal command zip -er ~/Desktop/myzippedfolder.zip ~/Documents/myfolder/ However, the contents of myzippedfolder will be a folder ...
2
votes
1answer
703 views

Can I compress SMS content to free up storage?

My SMS on my iPhone is growing everyday. According to my iPhone's Usage function, I have about 1.2GB of SMS data. My phone has been running on low storage and any megabytes are precious. Is there ...
2
votes
2answers
3k views

What is wrong with “compress” option?

In finder, I can cntrl + click on a file and click "compress"... Sometimes. It seems that randomly the option just won't show up and I have to open a new finder window, or duplicate the folder first, ...
1
vote
2answers
899 views

OSX: move to archive (compress a folder and remove it)

I'm looking for a way to zip (or 7z) files via a file manager in such a way that the original folder is deleted right after the zipping finished (less clutter when batching compression of multiple ...
3
votes
3answers
14k views

What does error “the Classic Environment is no longer supported” mean?

I created a .app file that is 303KB on disk. When I right click it and press Compress... I end up getting a 8.4MB .zip archive. I tried sending the .app via email to myself and compressing it on ...
0
votes
1answer
349 views

Extract jpeg File

Often files are hidden in .jpg files simply by opening them up with 7zip, then closing them again. Mac OS X archive utility does not have this ability. Is there any software available for osx that ...
1
vote
1answer
104 views

Extract zip file to different location without Terminal

Without third-party software, is there a way to extract a zip file to a different location without using Terminal? I realize I could use unzip file.zip -d /path/to/destination, but I'd love to do it ...
7
votes
3answers
49k views

How can I make a PDF document smaller?

Here's my problem, I have a PDF document 583KB, and I want to make it under 500KB so I can upload it. What should I do?