A video format.

Short for "Motion Picture Experts Group". These are the people who were tasked with coming up with a new video standard.

The problem with pure video data is that the files are truly huge - hundreds of gigabytes for a high quality hours'-worth of programme.

So video is normally 'compressed' for storage or before being passed through a network.

MPEG-4 is a 'lossy-compression' method which means a lot of the original data is thrown away - but the trick is to only throw away data in such a way that you do not notice a drop in video quality.

This standard describes how the video is to be compressed and de-compressed. Video files compressed with this standard will have a file extension of .mpeg

About 120 minutes of video, compressed with MPEG-4, can be stored on a DVD disk

See also MP3 which is an audio compression standard.

Challenge see if you can find out one extra fact on this topic that we haven't already told you

Click on this link: MPEG-4


back to glossaryback to glossary