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What is video compression?
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Way back in the day when digital video was first being born, video was stored in its pure, uncompressed format, much like digital audio (for those who don't know, CDs were pure uncompressed digital audio data, while newer standards such as Dolby Digital, MiniDisc, and MP3 are compressed). This meant that it took a LOT of space. For comparison on how much space video takes over audio, no matter how its stored, take for example the FM radio spectrum. TV Stations, like Radio stations, have a fixed frequency range which they operate on, however unlike FM we are never told the exact frequency at which they operate, our TVs are just hardwired with what frequency values correspond to channel 2, 3, 4 and so on. The ENTIRE FM spectrum exists in a tiny little gap between TV channels 4 and 5, which themselves (this is for a single channel) take something around 5 times more bandwidth than the whole FM band. Crazy, huh?

So one can imagine that back when digital video first came out, it was damn hard to store. Nowadays we have 100GB RAID arrays being common in not-so-expensive consumer setups. 10 years ago, 10GB was an ENORMOUS amount of space!! Hard drives didn't hold more than 500MB tops, but uncompressed digital video still took up the same space it does now. This lead to people storing digital video to tape and doing things with it that way, but this made Non-Linear video-editing impossible.

Then along came video compression. Probably the earliest, and truly successful video codecs (CODEC stands for COmpressor/DECompressor) was MPEG1. I'm sure you've all heard of MPEG (The Motion Picture Experts Group) in terms of its compression. But did you know that the actual standard for MPEG1 video is over a decade old? Not only that, but the MPEG2 standard used in DVDs is more than half a decade old!

Last update: 06:52 AM Tuesday, May 2, 2006

 



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