• MPEG stands for the Moving Picture Experts Group. MPEG is an ISO/TEC working group, established in 1988 to develop standards for digital audio and video formats.

• There are five MPEG standards being used or in development. Each compression standard was designed with a specific application and bit rate in mind, although MPEG compression scales well with increased bit rates.

• Bitrate, as the name implies, describes the rate at which bits are transferred from one location to another. In other words, it measures how much data is transmitted in a given amount of time. Bitrate is commonly measured in bits per second (bps), kilobits per second (Kbps), or megabits per second (Mbps).

MPEG1

• Designed for up to 1.5 Mbit/sec

• Standard for the compression of moving pictures and audio.

• This was based on CD- ROM video applications, and is a popular standard for video on the Internet, transmitted as mpg files.

• In addition, level 3 of MPEG-1 is the most popular standard for digital compression of audio-known as MP3.

MPEG2

• MPEG-2 is an enhanced version of MPEG-1

• Designed for between 1.5 and 15 Mbit/sec.

• It was specially designed for HDTV.

• HDTV is designed to provide a sense of immersion to the viewer. Hence it uses high resolution image frames.

• It is based on MPEG-1, but designed for the compression and transmission of digital broadcast television. The most significant enhancement from MPEG-1 is its ability to efficiently compress interlaced video.

• MPEG-2 scales well to HDTV resolution and bit rates, obviating the need for an MPEG-3

• The interlaced signal contains two fields of a videoframe captured at two different times. ... This technique uses two fields to create a frame. One field contains all odd-numbered lines in the image; the other contains all even-numbered lines.

MPEG4

• MPEG-4 is an advanced version of MPEG-2.

• MPEG-4 is based on object-based compression. Individual objects within a scene are tracked separately and compressed together to create an MPEG4 file.

• This results in very efficient compression that is very scalable, from low bit rates to very high.

• It also allows developers to control objects independently in a scene, and therefore introduce interactivity.