Fundamentals and Evolution of MPEG-2 Systems: Paving the MPEG Road

3Developments in Audio and Video Coding in MPEG

Why is video and audio compression needed and how much compression is required. What are the essentials of MPEG-1 and MPEG-2 video and audio compression technology. What are the various picture types used in MPEG video and what is the role of the VBV model. How MPEG-1 and MPEG-2 audio compression use a psycho-acoustic model. What are the building blocks of an MPEG audio and video decoder. How did video and audio compression technology evolve within MPEG.

3.1 The Need for Compression

New technology gets adopted by the market place once it offers added value in a cost-effective and commercially attractive manner. For audio and video compression, huge market interest evolved when it became evident that they would offer opportunities to introduce new applications and to improve the efficiency of existing applications. Two examples are given below.

• Compression of audio and video enables cost-effective distribution of movies and other audiovisual content on optical discs, such as Video CD, DVD and Blu-ray.
• Due to audio and video compression, radio and television broadcast services become more efficient. With a transmission channel that was used for broadcasting a single radio or TV programme in analogue form, now multiple programmes in digital form can be broadcast. Compression thereby offers broadcasters the option to broadcast more programmes to their customers and to reduce the transmission costs per programme. Indeed the use ...