M TO M

MPEG2 . Commercially produced DVD movies, home-recorded DVD discs, and most digital satellite TV broadcasts employ MPEG2 video compression to deliver their high-quality picture. MPEG2 is also the form of lossy compression used by TiVo-based hard disk video recorders. It can rival the DV format when it comes to picture quality. Because MPEG2 is a "heavier" form of compression that removes a larger portion of the original video signal than DV, however, it's more difficult to edit with precision. The MPEG2 codec allows for selectable amounts of compression to be applied, which is how home DVD recorders and hard disk video recorders can offer a range of recording speeds. MPEG2 is a second set of flexible compression standards created by the MPEG group. This set of standards takes advantage of the fact that over 95% of digital video is redundant, however some portions are much less redundant. MPEG2 handles this by using higher bit rates (ie higher quality) for more complex pictures and lower bit rates for simple pictures. MPEG-2 (1994) is the designation for a group of audio and video coding standards agreed upon by MPEG (Moving Pictures Experts Group), and published as the ISO/IEC 13818 international standard. MPEG-2 is typically used to encode audio and video for broadcast signals, including direct broadcast satellite and Cable TV. MPEG-2, with some modifications, is also the coding format used by standard commercial DVD movies.

MPEG4 . A flexible MPEG container format used for both streaming and downloadable Web content. It's the video format employed by a growing number of camcorders and cameras. (Moving Picture Experts Group) MPEG4 is the most recent version of a standard for the digital representation of video, audio and certain types of 3D information. It processes detailed 3D representation for faces, human bodies and general 3D scenes. The 3D scene representation points to the VRML standard as it's representation. MPEG-4, introduced in late 1998, is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). The primary uses for the MPEG-4 standard are web (streaming media) and CD distribution, conversational (videophone), and broadcast television.

MPEG7 . MPEG7 doesn't itself offer any new encoding features and it is not meant for representing audio/video content, unlike its siblings MPEG1, MPEG2 and MPEG4. Instead, it offers metadata information for audio and video files, allowing searching and indexing of audio/video data based on the information about the content instead of searching the actual content bitstream.
MPEG7 is based on XML and therefor is universal and all the existing tools that support XML parsing should be able to read the data as well, provided that they can ignore binary parts of the file.
MPEG7 is not used at the moment, but it is under serious development and standardization process at the moment and hopefully we see first fully featured MPEG-7 tools within few years.

MP2 - MP2, also known as Musicam, is a short form of MPEG Audio Layer II, and it is also used as a file extension for files containing audio data of this type. While it has largely been superseded by MP3 for PC and Internet applications, it remains a dominant standard for audio broadcasting as part of the DAB digital radio and DVB digital television standards. It is also used internally within the radio industry, for example in NPR's PRSS Content Depot programming distribution system.