MPEG4 is an international stadnard, related with the mobile image pack, established by ISO/IEC Joint Technical Committee. As MPEG1, a standard of Video-CD, MPEG2 standard of Digital TV have been made, the borders existing between broadcasting communication, and computer industries have been united with each other, to provide complex and diverse services. But as problems related with interchangeability have been brought up,studies have been made from 1993 reflecting this demand, resulting in MPEG4.MPEG4 is an A/V(Audio/Video) standard encoding mode, which can make transmissions even in communication media of narrow bandwidth and realize bi-directional multimedia.

Breaking from the convertible encoding mode in block unit used in existing H.261, JPEG, MPEG1, MPEG2, MPEG4 pursues a new mode of encoding image signals based on image contents. While MPEG1, MPEG2 focuses on rapid transmission with an elevated compression rate, MPEG4 aims for realizing ultra-low speed, high pack rate of 64kbps grade.

The functions are mainly an object-oriented interactive mode, high efficient pack, and universal access, etc. Object-oriented interactive mode function refers to the function in which the user can freely compose screen or sound by uniting screen or sound factors through linking and still treating such factors independently.

As an example, after dividing all objects on the screen into individual items and storing or transmitting them separately, the receiving party of information brings the divided objects together into one, enabling a completed screen.

One can replace the main character's face in a movie or game with his or her own photo.