Digital Video MPEG : Standards, Technology and Applications Lesson 2

MPEG-1 The MPEG (Moving Pictures Experts Group) committee began life in late 1988 by the hand of Leonardo Chairigloione and Hiroshi Yasuda with the immediate goal of standardizing video and audio for compact discs. A meeting between the International Standards Organization (ISO) and the International Electro technical Commission (IEC) in 1992 resulted in a standard for audio and video coding, known as MPEG-1.

MPEG-2 MPEG-2 became a bone fide standard in 1994 after a five day meeting of ISO and ITC in Singapore. The original application for MPEG-2 was all digital transmission of broadcast TV quality video, but now includes High Definition Television (HDTV). HDTV applications were to be covered by the MPEG-3 standard, but it was discovered that with some fine-tuning MPEG-2 could be used for this purpose and subsequently MPEG-3 was dropped.

MPEG Compression The job of MPEG is to take analogue or digital video signals and convert them to packets of digital data that are more efficiently transported over a network. Being digital it has the following advantages :

MPEG Compression Signal does not degrade Picture does not get fuzzy Signal-to-Noise ratio goes down slowly

MPEG Compression MPEG is derived from the original work by the Joint Pictures Expert Group (JPEG). The JPEG standard is for still images and is a lossy technique. It takes advantage of the nature of the human eye and removes redundant information that we just do not see.

Decoding

Differences between MPEG-1 and MPEG-2 MPEG-1 only allows for progressive picture sequences. MPEG-2 also allows interlaced sequences. MPEG-2 allows higher bit rates then MPEG-1. MPEG-2 allows surround sound, and alternate language channels. MPEG-2 has extra spatial scale ability information (so different decoders can get different quality outputs) MPEG-2 also allows temporal scale ability so that one stream can be displayed at different frame rates.

MPEG-2 CATV (Cable Television) CATV will use MPEG as the standard for compressing and decompressing video for distribution and for broadcasting. The need is perfect-quality video and the bandwidth is available to handle high bit rates. Because of this the industry has settled on MPEG-2 video although some are still using MPEG-1 on the interior.

MPEG-2 DBS (Direct Broadcast Satellite) This will use MPEG-2 audio and video for direct broadcast. DBS is a scheme of anywhere, anytime broadcasting.

MPEG-2 HDTV (High Definition Television) A U.S consortium has already agreed to use MPEG-2.

MPEG-2 Other Applications Other applications include : Digital video tape; High Density CD; Video Conferencing and Digital Camcorders.

Homework Due Monday, January 28, 2008 Writing Assignment Construct an essay on the advantages that are now presented through the advancement of technology for television and film. TWO Pages, TYPED, Double Spaced