• MPEG gets its name from the Motion Picture Experts Group, an international standards-settings panel responsible for creating and setting standards for various professional grade video technology, established in 1988.
• MPEG-1, the standard on which such products as Video CD and MP3 are based
• MPEG2 is a video compression standard, on which Digital Television set top boxes and DVD are based, though like Apples MOV files is ideally suited to sound recordings.
• MPEG-3 was designed to support high definition TV but this was supported by MPEG-2 (Hence MP3 was used for a sound format).
• MPEG-4 the standard for multimedia for the fixed and mobile web
• MPEG-7 the standard for description and search of audio and visual content
• MPEG-21 "Multimedia Framework" has started in June 2000.
• References
  • .(Millman, H. 1999, Mar) 
  • The MPEG Home Page. (Dec-2001). Retrieved 3/12/2002 from the World Wide Web: http://mpeg.telecomitalialab.com/ 

Movie shown above was reduced from a 606K AVI  to 101K Mpeg file.(move mouse over to play).

MPEG2 compression is also the technology currently being used for Direct Satellite Broadcasting.

Without compression, you would need 34-DVD's to store a 2 hour movie of the quality that you get with just one DVD. (The standard DVDs 4.7GB capacity could only store about 4 minutes of digital video)

This sophisticated compression technology works by analysing the video data and minimising the need to store repetitive or "redundant" data.

Since over 95% of the video data is redundant, it can be compressed without any noticeable effect on picture quality

Thanks to MPEG2, DVD compares favourably with D-1 digital video, a standard used by TV studios.

Since the number of bits that a disc can hold is fixed, the encoder must figure out how to allocate those bits for maximum efficiency. First it allocates more bits to complex images and fewer bits to simple images. Then it starts comparing each frame with the next. Picture information that is repeated from one frame to the next does not need to be stored again. Only the differences need to be encoded as new data.

MPEG2 encoding results in a variable video bit rate that averages about 3.5 megabits per second but can reach up to 10 megabits per second. For the audio signal, DVD uses Dolby AC-3 compression (Dolby Digital). With the addition of audio, subtitles, and other data, the bit rate averages nearly 5 megabits per second. Compare this with the video rate of 167 megabits per second specified by the D-1 standard used in TV studios, and you can see how efficient MPEG2 really is.

During playback, a DVD player uses an MPEG2 decoder to reconstruct or "decompress" the images. The result is true-to-life color, high resolution detail, and smooth movement that is virtually indistinguishable from the original uncompressed video.

• The standard is officially known as ISO/IEC Standard, Coded Representation of Picture, Audio and Multimedia/hypermedia Informat ion, ISO 11172.
• MPEG addresses the compression, decompression and synchronization of video and audio signals.
• At a compressed data rate of 1.2 Mbits per second, a coded resolution of 352 x 240 at 30 Hz is often used, and the resulting video quality is comparable to VHS.
• Image quality can be significantly improved by using a more highly-compressed data rate (for example, 2 M bits per second) without changing the coded resolution. 
• The following diagram shows a generalised decoding system for the audio and video streams.

•  MPEG-4 the standard for multimedia for the fixed and mobile web

•  MPEG-7 the standard for description and search of audio and visual content

• MPEG-21 "Multimedia Framework" has started in June 2000.
• MPEG-21 Overview v.3 (Dec-2001). Retrieved 3/12/2002 from the World Wide Web: http://mpeg.telecomitalialab.com/standards/mpeg-21/mpeg-21.htm