MP4 technology has opened a new horizon of possibilities for online media distribution and easy portability of audio-visual media. What MP3 music did a decade ago, MP4 videos are doing today. And as a result, it has made it possible to distribute high-quality audio-visual data through the internet. This has created an entirely new field of business paid video downloads.

But how does [TAG-TEC]MP4[/TAG-TEC] achieve all this? Dissemination of video data online is made possible by two properties of MP4 videos. First, it can provide an adequately high quality that ensures the unimpeded enjoyment of latest movie titles. Secondly, it produces files of a size that are small enough to be distributed online, or carried in a portable, personal video player. In other words, it must compress the video in such a way that a manageable file size is achieved, while not compromising on quality. What is the secret behind MP4 videos that makes all this possible?

Raw or uncompressed video data is absolutely huge in size. Try saving some television shows your hard drive without turning on any compression option, and you'll see what this means. A few minutes of raw video are enough to fill up completely even one of today's modern high-capacity hard drives. You'll soon run out of space onyour computer. So naturally, the solution is to compress the video data in such a way that it shrinks into a minuscule fraction of its original size, but does not lose quality in any perceptible way. [TAG-ICE]MP4[/TAG-ICE]does this by using highly optimizing codecs, which must be installed on your system if you want to either encode or watch MP4 videos.

What do the codecs actually do? Well, the procedure is too technical for a detailed explanation here, but the principle can be described. Both audio and visual data have a lot of elements in them which do not really contribute anything to the multimedia experience. There are a lot of audio frequencies or ranges of visual signals which do not really matter in the listening or watching, but they sit around nevertheless, taking up space in the video stream. The MP4 codecs identify these portions of the sound and the pictures, and discard them. The result is an MP4 video file that looks almost as good as the original, but is many, many times smaller!