Episode 59: December 26, 2012
by Eric Escobar
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.
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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?”
Which Do I Want?
Unfortunately, there isn’t a perfect answer that tips one way or the other. However there are many situations where each is superior.
For example, lossless files are great for original content as they will retain their full quality. If they ever needed to be shared, the file types could always be compressed to save on space.
This is an important concept: Files can always be converted from a lossless format to a lossy format, but they can never be converted back the other way. So you can’t regain quality once a file has been compressed.
Luckily for us, file compression has been around for quite a while and algorithms have been developed that make the compression as efficient as possible. What this means is that even though an .mp3 file is a lossy format, it still sounds great and saves on space. There are even circumstances now where it might be next to impossible to distinguish between a lossy file and a lossless file.
I recently took a Lifehacker test which compares the differences between lossless and lossy audio files. I thought for sure that I would be able to tell the difference, but to my surprise I definitely couldn’t! Try it for yourself and let me know what you think.
Here are you Quick and Dirty Tips for using lossy and lossless file types:
Lossy files sacrifice quality to save on space.
Lossless files sacrifice space to save on quality.
Lossy files can still retain great quality, depending on how much space you want to save.
Lossless files types are best for original files of music, pictures and video.
Lossless files can always be converted to a lossy file type but never the other way around.
Well, that’s it for today! Be sure to check out all my earlier episodes at techtalker.quickanddirtytips.com. And if you have further questions about this podcast or want to make a suggestion for a future episode, post your comments on the Tech Talker Facebook page.
Until next time, I’m the Tech Talker, keeping technology simple!