Video codecs are software applications that can compress video files so that they can be easily transmitted, usually over the Internet, and also decompresses these files for playback. These codecs are of great use in the world of digital video and the Internet, when it becomes difficult to transmit big chunks of video through the network. By compressing the video, the codec effectively decreases the size of the video which makes the transfer possible.
The video codec is a supplementary invention that has developed around compact discs. The presence of the compact disc made it necessary to store data onto it in a digital format. The development of Internet, especially the development of transmitting multimedia files over the Internet, provided the pace for the development of video codecs.
In any digital video file, there is a lot of data that can be compressed. This can be redundant data such as a string of data that contains of zero bits. Now, instead of representing all zero bits, a single integer can be used to indicate all of them. This is an example of how redundant data is bunched together to compress the overall file. This reduces the size of the file making it easier for transmission and storage.
The decompression works in exactly the opposite way. The individual binary digits are reassigned so that the video can be played back as much in its original form as possible.
Video codecs work by compressing the video for the size of the data contained in it as well as the amount of bandwidth that is required to transmit it. Different applications will have different ways of compressing data, but these are the general two ways in which this is done. Both kinds of compression are needed when using video files over the Internet.
Using video codecs is definitely essential in today's age, but the use is not without its compromises. One of the main compromises is on the quality of the data that is produced through the compression and subsequent decompression. When the data is compressed and then decompressed, there is always a possibility of loss and distortion of data. This cannot be avoided because compression is mostly an unpredictable process. It is difficult to say how the file will be compressed – each file has a different way of being compressed and each codec will use different principles too. That is the reason the end result cannot be predicted. In fact, professionals shun video codecs because of this reason.
There are two main types of codecs, called lossless and lossy. Lossless codecs are those that retain all information of the manner in which compression has taken place and use it during the decompression so that the decompressed file is as close to the original as possible. Lossy codecs do not retain this information. Thus there is a greater chance of distortion and loss of data with lossy codecs. However, because lossless codecs cannot compress to the extent that video transmissions over the Internet demands, usually lossy codecs are used for videos. These can give a compression of about 10:1, which is quite adequate for online video needs. Lossless video codecs, on the other hand, cannot compress any with more than a 2:1 ratio.
If you're like many who love to upload videos on youtube and elsewhere, you certainly should try video codecs.
