What is a MPEG-4?

Since audio and video files are so large, a way of compressing them while maintaining sufficiently good quality was desired. In the quest for a standard to accomplish this, the Moving Pictures Experts Group (MPEG) was established in 1988. The result was the MPEG family of standards for audio and video compression, created under the auspices of the International Standards Organization (ISO) and the International Telecommunications Union (ITU). Several MPEG standards, such as MPEG-3, have been deprecated. The standards still in use are: MPEG-1 and MPEG-2, used for video on CDs, DVDs, and digital television; MPEG-4 used for audio and visual data; MPEG-7 used for meta-data; and MPEG-21 intended for digital rights infrastructure.

When it comes to Internet media, MPEG-4 is considered the international standard. It is made for multimedia — not only audio and video but also text, 3-D objects, the computer graphics known as sprites, and other types of media as well. The basis for the MPEG-4 standard is the Apple QuickTime file format, and it was developed after MPEG-1 and MPEG-2. It was first approved in October of 1998, accepted as an international standard in 2000, and in 2002, it was itself included in QuickTime.

One of the key qualities of the MPEG-4 standard is that it is scalable. This means that it adjusts to different circumstances, working well at widely different data transfer rates. In other words, it can deliver content satisfactorily over dial-up connections as well as through high-bandwidth systems. It can deliver MPEG-2 video — that is, video of DVD quality — and do it using smaller files and even when working with lower data flow rates.

Even though MPEG-4 is a standard, there was some concern that it might be implemented in different ways, leading to frustration when moving between devices. The Internet Streaming Media Alliance (ISMA) — a group of 32 companies that was founded by Apple, IBM, Cisco, Philips, Kasenna, and Sun Microsystems — has taken on the task of ensuring interoperability in the implementation of MPEG-4. ISMA sets profiles to ensure that everything works together smoothly.

There is one part of the MPEG-4 standard that is often referred to separately. MPEG-4 part 10 is also called the H.264 video codec, and it appears as a choice in save menus in software like QuickTime, for example.