MPEG – Moving Picture Experts Group
MPEG (Moving Picture Experts Group) is ISO (International Organization for Standardization, International Organization for Standardization) and IEC (International Electrotechnical Commission, International Electrotechnical Commission) established in 1988 to develop international standards for moving pictures and voice compression .
standard transmission
The MPEG standards mainly include the following five, MPEG-1, MPEG-2, MPEG-4, MPEG-7, and MPEG-21. The expert was formed in 1988 to specialize in establishing video and audio standards for CDs, and its members are technical experts in the fields of video, audio, and systems. Later, they successfully separated sound and video recording from the traditional analog method, established the ISO/IEC11172 compression coding standard, and formulated the MPEG format, which brought audio-visual communication into the digital age. Therefore, the MPEG-X version that everyone is now referring to is the video, audio, and data compression standard formulated and published by ISO (International Organization for Standardization).
The video compression coding technology of the MPEG standard mainly uses motion-compensated inter-frame compression coding technology to reduce temporal redundancy, DCT technology to reduce spatial redundancy of the image, and entropy coding to reduce image spatial redundancy. statistical representation of information. redundancy. The comprehensive application of these technologies greatly improves compression performance.
MPEG-1
The MPEG-1 standard was officially published in 1992, the standard number is ISO/IEC11172, and its title is “The code rate is approximately 1.5 Mb/s for moving images of digital storage media and the sound that accompanies. of encoding “. MPEG-1 mainly solves the multimedia storage problem. Its successful formulation makes MPEG-1 products represented by VCD and MP3 spread rapidly in the world.
MPEG-1 Layer 1 digital audio cassette
MPEG-1 Layer 2 DAB, VCD
MPEG-1 Layer 3 Internet, MP3 Music
MPEG-1 Audio Layer 1
Type: Sound
Producer: MPEG
Bandwidth required: 384 kbps 4:1 compression rate
Features: Easy to encode, for digital cassette tapes, 2 channel, audio used on VCD used on VCD is MPEG-1 layer I.
Advantages: The compression method is much more complicated than the time-domain compression technology, and the coding efficiency and sound quality are also greatly improved. increases correspondingly. Can achieve “fully transparent” sound quality (EBU sound quality standard)
Disadvantage: higher bandwidth requirements
Field of application: voip
Royalty Method: Free
Remarks: MPEG-1 sound compression coding is the world’s first high-fidelity sound data compression of high-fidelity sound in the world. It is divided into three levels:
–Layer 1: Simple encoding for digital cassette tapes
–Layer 2: Medium complexity algorithm, used for digital audio transmission (DAB) and VCD, etc.
–Layer 3 (Layer 3): complex coding, used for high-quality sound transmission on the Internet, such as MP3 music compression 10 times.
