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 entirety of 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

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 352×240 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 720×480 and 1280×720 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-2 contains two separate but related container formats that give maximum functionality to all MPEG videos. The first container format in an MPEG-2 file, known as the “transport stream,” is used in situations where the beginning and end of the video stream are unknown, which may include digital broadcasting and magnetic tapes. The second container format in an MPEG-2 file, known as the “program stream,” is used in situations where the entire file is available, which include storage devices such as hard drives, flash drives, and optical discs.

MPEG-4

Introduced in late 1998, MPEG-4 is based 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).

MPEG 4 implements 27 different parts which are useable in a wide range of applications. The MPEG 4 format is versatile enough to work in high definition video media such as Bluray Discs. There is increased efficiency in the encoding process and mixed media data such as video audio and speech.

The different parts of the MPEG 4 format are designed to allow the user of the format in media creation to have the largest flexibility available. They can implement the parts they need to make the media work how they need it. The following are the 27 parts and what they are used for:

  • Part 1 – Synchronization and multiplexing of video and sound data
  • Part 2 – The compression codec for visual data
  • Part 3 – Compression codec for sound used in many different ways
  • Part 4 – Used for conformance testing
  • Part 5 – Reference software to clarify the standard
  • Part 6 – Multimedia framework for integration and delivery
  • Part 7 – Samples to make improvements
  • Part 8 – ISO Compliant IP Network Carry Method
  • Part 9 – Hardware designs for improvements
  • Part 10 – Advanced Video Coding
  • Part 11 – Scene Description Engine
  • Part 12 – ISO base media file format
  • Part 13 – Intellectual Property Management and Protection (DRM)
  • Part 14 – MP4 File Format
  • Part 15 – Advanced Video Coding File Format
  • Part 16 – Animation Framework Extension
  • Part 17 – The Streaming Text Format
  • Part 18 – Font Compression and Streaming
  • Part 19 – Synthesized Texture Format
  • Part 20 – Simple Aggregation Format
  • Part 21 – MPEG J Graphics Extension
  • Part 22 – Open Font Format
  • Part 23 – Symbolic Music Representation
  • Part 24 – Audio and Systems Interaction
  • Part 25 – 3D Graphics Compression Model
  • Part 26 – Audio Conformance
  • Part 27 – 3D Graphics Conformance
As MPEG-4 is a proprietary technology, it requires licensing in order to be used. Just getting access to the base standards documents costs money, and anyone who wishes to create a program that can play back or encode files in MPEG-4 must first purchase a license from The MPEG Licensing Authority. There are currently many companies which have licensed the technology including prominent technology companies such as: Canon, General Electric, Mitsubishi, Microsoft, Samsung, Sony, and Toshiba just to name a few.

Playing MPEG Files

MPEG files can be played in most media player software, such as Windows Media Player and VLC Player. If the user’s media player software does not recognize MPEG files, he/she may need to download and install MPEG codecs, which can be found as a stand-alone codec file or in the popular codec pack, K-Lite Codec Pack.

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.