Video trans-coding is the translation of one digital video format into another to make videos view able across different platforms and devices and is typically used to mean translating all three elements of a digital video at the same time – the file format, the video, and the audio. It is used in many steps of the digital video life-cycle and is an extremely important part of online video broadcasting. The process of video trans-coding is normally a two-step process. The first part of the process is decoding. This is whereby the original data is transferred to an uncompressed format. The second part of the process is the re- encoding – whereby the data will now be transferred to the new device in the desired format. One of the most important reasons why video trans-coding is done is when you need to transfer or upload files onto websites and other video sharing sites. Trans-coding is also used in the home in the home PC software when you want to trans-code say MPEG-2 files into either MPEG-4 or H.264 format. Trans-coding a video is done due to some of the circumstances : • When the target device does not support the format that the original data. • When the target device has a reduced capacity such that the capacity of the original file will have to be reduced so that it can fit to the new format. • In order to convert incompatible and obsolete file types into a modern format that is better supported by the new device.