What is MPEG?

     MPEG (Moving Picture Experts Group) is an International Standards Organization (ISO) group which sets standards for compressing and storing video, audio, and animation in digital form.

     Moving Picture Experts Group's first meeting was in Ottawa, Canada, in May of 1988. Over the years, MPEG has developed to include around 350 members per meeting from several industries, research institutions, and universities. The official designation of Moving Picture Experts Group is ISO/IEC JTC1/SC29 WG11.

     Pronounced "m-peg", the term MPEG represents the entire digital video compression techniques and the digital file formats created by the Moving Picture Experts Group. Generally, MPEG can create high quality video files when compared with other competing formats like Video for Windows, QuickTime, and Indeo. MPEG files can be decoded with the help of software programs or by using special hardware.

     MPEG files attain high compression rates by only storing the changes which occur between two frames, rather than storing the entire frame. The technique used by MPEG to encode video information is known as DCT. Much like JPEG, MPEG utilizes a lossy compression technique in which certain data is removed from the files. However, end users cannot normally notice a reduction in quality as the reduction of data is hardly noticeable to the human eye.

MPEG Standards

     Though there are several MPEG standards, MPEG-1, MPEG-2, and MPEG-4 are three most popular MPEG standards:

MPEG-1: MPEG-1, the first video and audio compression standard, supports a video resolution of 352x240 at the rate of 30 fps (frames per second). However, the video quality of MPEG-1 is slightly lower than the video quality offered by a normal VCR. MPEG-1 also has the ability to include audio compressed in the MP3 audio format.

MPEG-2: MPEG-2 can support video resolutions of 720x480 and 1280x720 at 60 frames per second, with an audio quality equal to conventional CD audio. MPEG-2 is suitable for almost all television standards, including ATSC, NTSC and HDTV. MPEG-2 has the capability to reduce a two hour video file to a few gigabytes of data. Encoding video to MPEG-2 requires fairly significant processing power, but decoding MPEG-2 data to video is not as processor intensive. The MPEG-2 standards is also used to store data on DVD's.

MPEG-4: Introduced in late 1998, MPEG-4 is base on MPEG-1, MPEG-2, and Apple QuickTime technology. This graphics and video compression algorithm standard comes with the ability to create wavelet-based files which are smaller than QuickTime or JPEG files. MPEG-4 files are designed so as to transmit images and video while using less network bandwidth. MPEG-4 files can combine video with graphics, text, and 2-D and 3-D animation layers.

Additional features which can be seen in MPEG-4 include object oriented composite files (such as video, audio, and VRML objects), VRML support for 3D rendering, and support for externally specified DRM (Digital Rights Management).

Other MPEG standards

     MPEG-3: MPEG-3 was originally developed for HDTV; but as the MPEG-2 standard was found to be more efficient for HDTV, MPEG-3 was abandoned.

MPEG-7: MPEG-7 is a formal standard for illustrating multimedia content.

MPEG-21: MPEG-21 is designed to share machine-readable license information in an "ubiquitous, unambiguous and secure" manner.