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Video compression is the reduction of the size of a video file. Video file types like AVI or MPEG are basically a collection of images being shown together. We use video compression to reduce the size of a video file in order to fit it on different formats. Basically we compress video in order to store video as it takes up such a large amount of storage space in its original form.
The compression method is based around the fact that videos come in frames per second (the frames being the collection of images I mentioned earlier). Most videos are saved to TV quality setting ie. 30 frames per second.The more frames per second a video has the better its quality .One way of reducing the size of a video (compression) is to reduce the amount of frames per second .
In order to reduce the amount of frames per second from the full size video, a video compression technique is used where by if two consecutive frames are identical the second frames is moved. This unnoticeable edit reduces the overall size of the video making it easier to copy to a larger amount of different formats such as DVD, CDR,DVD RW etc.
Another variation of this technique is if in the second frame the only difference is a single movement of part of the frame, the rest of this frame is cut. For example, imagine a video where there is one person talking and that this person is not moving. On the first frame the image is shown complete, but on the second frame the parts of the image that are identical to the first frame are removed from the image. If only the mouth of the person is moving, only the area around the mouth will be drawn on the second frame .In this way we are again saving space, thus compressing the video.
As the Internet matures, it seems clear that analog media such as videotape, film, and broadcast will overshadowed by media being sent over the Internet. For example, over 18 billion streaming videos were served in 2005, up from 284 million in 1998. This digital infrastructure will allow data to be transferred between any two computing machines on the planet. However, the speed at which this data can be sent will depend on a number of factors. It will mostly depend on the type of modem you have.Also moving data costs money. At the present time, the cost of sending one megabyte over the Internet usually costs anywhere from 5 cents at low volume, down to as low as one cent at extremely high volume. Therefore, the cost of transporting a megabyte of data from one place to another is always more than a penny.
Uncompressed, a digitized broadcast television signal uses approximately 160 million bits, or 20 megabytes of data per second. Therefore, transmitting an hour of uncompressed video costs at least $700 (20 * 3600 = 72,000 cents or $720). Obviously this is not very competitive with existing technology, even if it is fas . However, some companies are now able to compress video down to one megabit per second or less. Which will bring the cost of sending an hour of broadcast quality video over the Internet to less than one Euro. This sees it competing with analog technologies. This could have a large effect on the entire broadcasting industry.
Internet companies such as Adobe, AOL , and skype are using companies such as ON2 to compress there videos .Skype for example alloxs us to chat on line using video links so you can see who you are talking to anywhere in the world ,for free!.
Personally I think the importance of video compression is highly overlooked. In today’s world we download and upload videos onto different formats everyday ,especially on the internet. I believe that the importance of video compression will become more apparent in the next few years with rise of popularity of sites such as youtube and mobile phone video technology .