College Task 2 - Video Fact Profile Continued...2

Interpolation = Motion interpolation is a form of video processing in which animation frames are generated between existing ones, in an attempt to make animation more fluid.

Compression = Video takes up a lot of space. Uncompressed footage from a camcorder takes up about 17MB per second of video. Because it takes up so much space, video must be compressed before it is put on the web. “Compressed” means that the information is packed into a smaller space. There are two kinds of compression: lossy and lossless.

Lossy compression = Lossy compression means that the compressed file has less data in it than the original file. In some cases this means lower quality files, because information has been “lost,” hence the name. However, a relatively large amount of data is lost before being noticed as a difference by the human eye. Lossy compression makes up for the loss in quality by producing comparatively small files. For example, DVDs are compressed using the MPEG-2 format, which can make files 15 to 30 times smaller.

Lossless compression = Lossless compression is compression where none of the information is lost. This is not as useful because files often end up being the same size as they were before compression. This may seem pointless, as reducing the file size is the primary goal of compression. However, if file size is not an issue, using lossless compression will result in a perfect-quality picture. For example, transferring files from one computer to another using a hard drive might choose to use lossless compression to keep the quality.

Codecs = Codec is a short name for coder-decoder, the software that takes a raw data file and turns it into a compressed file. Because compressed files only contain some of the data found in the original file, the codec is the “translator” that decides what data makes it in to the compressed version and what data gets discarded.

Different codecs translate in different ways, so a video file compressed using the Intel Indeo codec will be different from a file compressed using the Cinepak codec, for example. Sometimes the difference is noticeable, sometimes not, such examples consist of codecs codes like MP4, MPEG, h.264 (used the most) etc.

Progressive downloads =   Progressive download is a term used to describe the transfer of digital media files from a server to a client. The consumer may begin playback of the media before the download is complete. The difference between streaming media and progressive download is how the digital media data is received and stored by the end user device that is accessing the digital media.

That means that once the video begins downloading to the consumer’s temporary files for viewing. Because of this, the consumer can only watch up to the point in the video that has been downloaded so far. Also, the visitor cannot skip ahead until the entire video has been downloaded.

This is the preferred method of transmitting Flash video over the web and can be seen at YouTube, Google Video, MySpace, and almost any other video-enabled social video networking site.

The larger the file, the longer it will take to convert and upload to the server. Consequently, it will also take a long time to download depending on the consumer’s connection.

What colour saturation does = removes the colour therefore the image becomes black and white