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What is MPEG?

Why should anyone care ?

Here’s why: Everyone knows that digital media is made up of “ones and zeros.” How those ones and zeros get encoded and decoded will help to determine how great the sound is and how pretty the pictures look.

MPEG is a governing body which develops standards for that encoding and decoding.
MPEG stands for Motion Picture Experts Group. The “group” is made up of industry people from all over the world. Those folks decide how high to “set the bar” in terms of technical quality. They also decide on the best approach to meet that goal. The researchers and engineers who make up the group must be doing something right.

They have racked up multiple awards including Emmys and have been in business for almost twenty years .

For this discussion,we will focus on three MPEG “standards” These standards are MPEG 1,MPEG 2 and MPEG 4. You may hear about other MPEG “numbers” like 3,7 or 21.

We’ll save those for another time. MPEG 1 as you might have guessed is the “granddaddy” of all the MPEG standards. Some examples of applications of MPEG 1 include video cd and mp3.
(Don’t confuse mp3 and MPEG 3. They are very different !)

MPEG 2 can be found in over the air digital tv,direct broadcast via satellite,video on demand and dvd. MPEG 2 plays a big role in some ‘modern” video formats like HDV.

MPEG 4 is the successor to the earlier standards. It allows for the incorporation of diverse elements (like graphics) into the bitstream. MPEG 4 is backwards compatible
with MPEG 1 & MPEG 2. Many people are aware of the interoperable features of MPEG 4 and Quicktime.

It might sound like the various MPEG standards are perfect ! Close,but not exactly. Digital media tends to rely on something called “compression.” This essentially means that, “new pictures” are only made when there is a change in the old picture.

The example that I will usually use is that of a “talking head” newscaster. If the talent is very “wooden”,”new pictures” might only consist of lip movement. On the other hand,if you are shooting an automobile race from the infield,you are making lots of “new pictures.”

Presumably ,the camera is panning and the fans are moving as the cars are coming around the track. If the compression algorithm does not do its job correctly, you might experience motion artifacts or what some people call pixellation.(Also see “sparklies !”)

Precise, frame accurate editing can also sometimes be a challenge in the MPEG world.
This is due to the so called “interframe” nature of the format(s). You may have heard the term “group of pictures” in this context. What this essentially means is that it may be difficult to isolate any given frame during an edit because of its linkage with other frames.

To summarize,though there may be some challenges,we owe a debt of gratitude to the selfless individuals who make up the Motion Picture Experts Group. They had the vision to see beyond analog and lead us to the digital frontier. They and their successors will continue to strive to provide the absolute best quality video and audio while still keeping an eye on the bottom line.