Science and technology

7 Linux command-line suggestions for saving media file house

Have media information in your pc? You can doubtless reclaim vital disk house by storing that knowledge in additional space-efficient file codecs.

This article demonstrates easy methods to use Linux line instructions to carry out the most typical space-saving conversions. I exploit line instructions as a result of they offer you full management over compression and format conversion options. Also, you will want to make use of line instructions if you wish to write scripts. That permits you to develop applications which might be custom-tailored to your personal distinctive wants.

While this text covers terminal instructions, there are lots of different methods to compress and convert information. You can set up an open supply conversion GUI software onto your pc, or you may even convert file codecs utilizing the save as and export capabilities of many widespread purposes.

This article discusses solely a handful of the preferred file codecs and terminal instructions among the many a whole lot that exist. The purpose is to present you most profit whereas conserving it easy.

File deletion

Before you begin your file-format conversions, it is useful to determine after which delete any enormous however undesirable information you will have in your pc. Deleting only a handful of house hogs yields outsized advantages.

The du, ncdu, and dust instructions listing the most important subdirectories beneath the present listing. They inform you which directories use essentially the most disk house:

$ du -a .  |  type -n -r  |  head -n 50

This command string identifies the 50 greatest information in its recursive listing tree. It lists these greatest information sorted by dimension:

$ discover  -type f  -exec  du -Sh {} +  |  type -rh  |  head -n 50

With this command, you may immediately acknowledge when you will have massive information saved in a couple of location. Delete the duplicates, and you’ll reclaim some vital house. The output additionally helps you determine after which delete any large information you now not want.

Quality or space for storing

Media information that maintain pictures, audio, and video could use a whole lot of various file codecs. There’s typically a trade-off between knowledge high quality on the one hand and the space for storing consumed on the opposite.

Some file codecs are lossless: They protect all of the initially captured knowledge. Lossless file codecs can both be uncompressed or compressed. They range in dimension by this and different components.

Other file codecs are lossy. They save space for storing by cleverly eliminating among the least helpful knowledge. They’re supreme in case your use of the info is such that you would be able to tolerate some minor knowledge loss.

For instance, capturing a digital picture in a lossless format like RAW, PNG, or BMP creates a giant file. Converting that picture to a lossy various like JPG or WEBP saves a number of house. Is it value it? That depends upon your meant use of the picture.

If you are an expert photographer who prints {a photograph} in a high-quality ebook, you in all probability need to hold your authentic lossless file. You doubtless require the best high quality picture in your art work. Your lossless file additionally means you may carry out intensive picture modifying with out shedding high quality.

If you are an internet site developer, you would possibly make the other selection. Smaller lossy JPG or WEBP information obtain to customers’ computer systems a lot quicker than lossless pictures, making your webpages load extra shortly. This conversion works as a result of few customers can inform whether or not the picture they view on their pc or cellphone display is lossless or lossy.

Keep in thoughts that after you change from a lossless format to a lossy one, you’ve got eliminated some knowledge. You cannot convert again to regain that knowledge. You can convert again to the earlier format, however you accomplish that with out the info you’ve got already sacrificed. Only delete the unique file when you’re glad that the transformed file meets all of your wants! You could select to not delete the unique file in any respect.

Sometimes, saving house is a matter of saving handy house. If authentic, lossless, uncompressed information are vital to you for any purpose, again them as much as a separate storage location. You could not want that full-quality WAV file in your working pc daily, however you is likely to be pleased to have entry to it later.

Converting picture information

Several widespread bit-mapped file codecs current nice alternatives for saving house, together with RAW, BMP, GIF, and TIFF. The widely-used PNG format can also be an excellent candidate.

One doable conversion goal for pictures is the lossy JPG format. With its high quality settings, JPG permits you to specify a smaller file dimension with larger knowledge loss or a bigger file dimension with much less loss. It would possibly provide you with a compression ratio of as much as 10:1 over some lossless codecs. Yet when you show a JPG picture on a pc or telephone display, the attention can not often inform that conversion and compression have occurred.

A WEBP file appears to be like simply pretty much as good on screens as JPG information, however they save much more house. This financial savings is why WEBP is turning into the preferred lossy picture format, supported by all trendy browsers and most modern apps. The WEBP format provides alpha transparency, animation, and good coloration radiance. It’s practically all the time used as a lossy format, although it helps lossless as nicely.

I transformed most of my PNG and JPG information to WEBP format and reclaimed a great deal of space for storing. On one disk, 500 megabytes of PNG information melted all the way down to about 120 meg of WEBP. If you are sure that your pictures are solely ever going to be displayed on a display, changing to WEBP provides clear advantages.

The open supply ImageMagick utility offers you Linux terminal instructions to transform pictures. You in all probability want to put in it first:

$  sudo apt set up imagemagick

ImageMagick line instructions aid you scale back picture file sizes by means of three methods:

  • Changing the file format
  • Changing the diploma of compression
  • Making the picture smaller

Here’s the syntax of the ImageMagick convert command that performs file format conversions:

convert  [input options]  input_file   [output options]  output_file

These examples all lowered file dimension, as you may see from the outcomes of pattern runs:

$ convert picture.bmp  new_image.jpg   #  7.4MB all the way down to 1.1MB
$ convert picture.tiff new_image.jpg   #  7.4MB all the way down to 1.1MB
$ convert picture.png  new_image.webp  #  4.8MB all the way down to 515KB
$ convert picture.png  new_mage.webp   #  1.5MB all the way down to 560KB
$ convert picture.jpg  new_image.webp  #  769KB all the way down to 512KB
$ convert picture.gif  new_image.jpg   #  13.2MB all the way down to 10.9MB
$ convert picture.gif  new_image.webp  #  13.2MB all the way down to 4.1MB

You can convert RAW pictures, too. When changing a RAW picture, its filename should not have an extension for the convert command to course of it accurately.

$ convert picture new_image.png #  RAW 67.1MB all the way down to 45.3MB

There are some vital house financial savings to be gained, however provided that the output is suitable in your use case.

This instance saves house by resizing a JPG picture to as close to as 800×600 as doable whereas nonetheless retaining the right facet ratio. In this instance, I convert a 285KB enter file at 1277×824 pixels to a 51KB output file at 800×600 pixels.

$ convert picture.jpg  -resize 800x600  new_image.jpg

The convert command can change pictures nevertheless you want. For instance, you may specify the trade-off between picture high quality and dimension. But you will must wade by means of its many choices to grasp its full capabilities. For extra about ImageMagick, learn Greg Pittman’s Getting started with ImageMagick, or go to the ImageMagick website.

Converting audio information

Like picture information, audio information are available in lossless uncompressed, lossless compressed, and lossy codecs.

As with pictures, the trade-off between lossless and lossy is primarily knowledge high quality versus saving house. If you require the best high quality audio, stick to lossless information. That is likely to be the case when you edit digitized music, for instance. If you need listenable music that consumes far much less house, a lot of the world has determined that lossy codecs like MP3, M4A, and OPUS are the only option.

Here are the preferred audio codecs. Note that file extensions typically check with containers that may assist a couple of audio encoding format and that the majority applied sciences declare greater than a single file extension. This chart lists the most typical eventualities you will see:

  • Lossless and uncompressed
  • Lossless and compressed
  • Lossy
    • WEBM
    • OPUS
    • OGG (Vorbis)
    • AAC (some implementations of this should not open codecs)
    • MP3
    • M4A
    • WMA (not an open format)

If your purpose is to avoid wasting disk house, strive changing from a lossless format to a lossy one. Don’t convert from one lossy format to a different until it’s important to. That will doubtless degrade the sound high quality an excessive amount of.

A really versatile Linux terminal command to transform audio information is ffmpeg. To set up it:

$ sudo apt set up ffmpeg

Like the ImageMagick convert command, ffmpeg helps a staggering vary of file codecs and codecs. View all of them by getting into:

$ ffmpeg -encoders

Using ffmpeg is often fairly simple. Here’s the usual syntax. The -i flag identifies the enter file, and the -vn flag tells ffmpeg to not invoke any video-related code that may alter the audio output:

$ ffmpeg  -i  audiofile_input.ext -vn

These examples all convert lossless WAV information into lossy codecs to avoid wasting house. The course of to transform AIFF information is similar (however exchange .wav with .aiff):

$ ffmpeg -i audio.wav -vn audio.ogg  # 38.3MB to three.3MB
$ ffmpeg -i audio.wav -vn audio.mp3  # 38.3MB to three.5MB
$ ffmpeg -i audio.wav -vn audio.m4a  # 38.3MB to three.6MB
$ ffmpeg -i audio.wav -vn audio.webm # 38.3MB to 2.9MB

All the instructions lowered the scale of the lossless enter information by an element of 10. The large query: Do the outputs sound totally different from the originals? Well, it relies upon. To most individuals listening on most shopper units, the distinction is negligible. That’s why MP3, M4A, and different compressed codecs are the world’s hottest music codecs. Even although it is not technically the very best, the audio is kind of listenable, and it consumes a fraction of the space for storing (or bandwidth, when streaming).

Converting video information

Video conversion presents one other probability to avoid wasting a number of house. Your purpose needs to be to seek out the video format that greatest balances playback high quality and file dimension to satisfy your wants.

A video format is the mix of a container file format and a codec. A codec is software program that encodes and decodes a knowledge stream because it strikes to and from the container file.

Containers may be paired with a number of codecs. In apply, there are sometimes just one or two or three widespread codecs paired with a specific container. For instance, with audio information, WAV information may be encoded as both lossless or lossy, however lossless encoding predominates the format such that most individuals assume that any WAV file is lossless.

These are a few of in the present day’s most generally used open supply video codecs:

  • The MP4 format, containing H.264 video and AAC audio, is utilized in BluRay and Internet streaming.
  • The WEBM format, containing VP9 video and Opus audio, is remarkably versatile and is used for each archival-quality information in addition to smaller information for streaming.
  • The Matroska (MKV) container format can include practically any mixture of video, audio, and even stereoscopic (3D) imagery. It’s the premise for WEBM.

The predominant components that decide video file dimension and high quality are:

  • Resolution (dimension of the body)
  • Bitrate
  • Encoding

The ffmpeg command can change all three parameters. Here’s a easy conversion instance:

$ ffmpeg -i output.webm

This conversion resulted in a 1.8 MB output file from a 39 MB enter.

Because I did not specify any parameters, ffmpeg copies a lot of the present attributes of the enter file. In this instance, my enter file was a MOV file containing MJPEG video with a decision of 1280×720, a body charge of 23.98, and a bitrate of 40,219 kilobytes per second (kbps). The ensuing output file comprises VP9 video with the identical decision and body charge. However, the bitrate is only one,893 kbps.

As with audio conversions, video compression ratios are spectacular, and the potential house financial savings are huge. On my PC, these conversions considered so equally to the unique that it was tough to inform whether or not there was any degradation—which, for my functions, is pretty much as good as saying that there was no degradation.

Whether the output high quality is suitable to you depends upon your meant use of the video, your viewing units, and your expectations. Never erase your authentic file till you’ve reviewed the transformed file and located it passable.

Archival storage

Archiving takes a number of enter information—typically of various file sorts—and collects them right into a single output file. Compression is optionally available. A compressed archive is beneficial for sending information throughout the web and for long-term knowledge storage. It’s an effective way to avoid wasting house. The draw back is that you just’re restricted in how one can course of archived information till you extract them out of the archive (although some instruments are actually fairly refined of their manipulation of information inside archives).

Among the various archive file codecs, the preferred compressed codecs embrace GZ, BZ2, XZ, ZIP, and 7Z. The tar command handles many archive codecs. It helps compression instructions together with gzip, bzip2, xz, and others.

$ tar --xz --create --file myarchive.tar.xz bigfile.xcf bigfile.tiff

This command lowered 56 MB all the way down to a 28 MB compressed archive. How a lot compression happens varies extensively by the information concerned. Some media information (particularly these already in a compressed format) compress little or under no circumstances.

To unarchive a TAR file, use the --extract choice:

$ tar --extract --file myarchive.tar.xz

The tar command bundles many information into one container (generally referred to as a tarball). If you are compressing just one file, nevertheless, there is not any want for a container.

Instead, you may simply compress the file with instructions like gzip, bzip2, xz, zip, 7z, and others.

$ xz bigfile.xcf
$ ls

To uncompress a compressed file, you may often use an “un” model of the command you used to compress the file:

$ unxz bigfile.xcf.xz

Sometimes there’s additionally a --decompress choice:

$ xz --decompress bigfile.xcf.xz

Not all Linux distributions embrace all these instructions, so you could have to put in a few of them.

Scripting suggestions

To convert all of the information in a listing, merely embed your conversion command inside a for loop. Place double quotes across the filename variable to deal with any filenames that include embedded areas. This script converts all PNG information in a listing to WEBP information:

for file_name in *.png ; do  
  convert "$file_name"  "$file_name".webp

To course of all of the information in a listing and all its subdirectories, you must recursively traverse the listing construction. Use the pushd and popd stack commands or the find command for this.


Used prudently, Linux instructions that compress and reformat media information can prevent gigabytes of storage. I’m positive you’ve got obtained some nice suggestions of your personal, so please add them within the feedback.

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