Audio, Video, and Image Formats

Tech Talker explains the difference between lossless and lossy file formats. Which type of file is right for you? Click to find out.

Eric Escobar,
December 26, 2012
Episode #059

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Listening to music and podcasts seems pretty simple, right? You just double click the audio or video file and your content begins to play, no questions asked. Well, as always with technology, there is much more going on under the hood. There are many different types of file formats for audio, video, and images such as the traditional “.avi,” “.jpg,” “.mp3,” and other file formats. So in this week’s episode I’ll be going over all these content types, how they’re different, and why it matters.>

Digital File Types

When an audio file gets recorded, there is a ton of information that a computer has to deal with. But most importantly, a computer can decide to handle this information in two different ways.  It can either store a large file size with all of the data that was created, or it can compress the data which will reduce file size, but decrease quality.

This is the same concept when talking about video, audio, and images. The highest quality of any of these types of files will often be the largest. Depending on the purpose, the quality of an item may not need to be as good as possible. If you were to take a picture to use as a wallet photo, it would definitely not need to meet the same quality standards as a photo that was going to be used for a billboard.

A computer can scale the quality of a file based on how much the file is compressed. The higher this compression, the less quality your file will have. When a file is being compressed, the computer finds ways to cut out small pieces of information or simplify them. So say you took a picture that had 4 different shades of blue, a highly compressed version of that picture may only show one or two types of blue. This reduces the size of the file because the computer is simplifying what is there.

Lossy v. Lossless

When a file loses quality due to this type of compression, we call it a lossy file, because it loses its original quality. On the other hand, a file that keeps all four shades of blue would be a lossless file because it didn’t lose any quality.

Lossy files such as .mp3 and .aac compress the audio information quite a bit, and remove a lot of unnecessary information which a human may not necessarily be able to pick up on. This is great because it would allow you to have more music on your iPod because these files don’t take up as much space.

If that same audio file were stored in a lossless format such as FLAC, ALAC, or WAV, it would retain all of the information exactly as it was recorded. This makes for amazing sound quality, however you’re often left with a file size that can be anywhere from 3 to 10 times as large as a lossy file.

So we have lossy files and we have lossless files. Lossy files lose quality but save on space, and lossless files retain quality but require much more space for storage.

Which leads to the question: “Which do I want?”