Recognize MPEG video compression standards and related encoding formats

The full name of MPEG is the Moving Picture Experts Group, an organization that specializes in the development of international standards in the field of multimedia. Founded in 1988, the organization is made up of approximately 300 multimedia technology experts worldwide. Including MPEG video, MPEG audio and MPEG system (video and audio synchronization) three parts.

The MPEG compression standard is designed for moving images. The basic method is to collect and save the first frame information in unit time, and then store only the remaining frames relative to the first frame. Achieve the purpose of compression. The MPEG compression standard can achieve compression between frames, with an average compression ratio of 50:1, a high compression ratio, and a uniform format with good compatibility.

In the multimedia data compression standard, more MPEG series standards are adopted, including MPEG-1, 2, 4, and so on. MPEG-1 (ISO/IEC 11172) is the first multimedia international standard with extensive influence proposed by the MPEG organization in 1992. The official name of the MPEG-1 standard is "Compression Standards for Moving Pictures and Sound Based on Digital Storage Media." It can be seen that MPEG-1 focuses on solving multimedia storage problems. Due to the successful formulation of MPEG-1, MPEG-1 products represented by VCD and MP3 are rapidly spreading worldwide.

Following the successful development of MPEG-1, the MPEG organization introduced the MPEG-2 standard for multimedia transmission problems in 1996. The official name of MPEG-2 is "Universal Image and Sound Compression Standard." The most compelling products of the MPEG-2 standard are digital TV set-top boxes and DVDs.

Since then, MPEG has not stopped moving forward. In January 1999, the first version of the ISO MPEG-4 (Compression of Video and Audio Objects) standard was released, which was subsequently announced in December 1999. The second edition of this standard. The official ISO of MPEG-4 is named ISO/IEC14496. MPEG-4 was first proposed in May 1991, officially launched in July 1993, and became an international standard in January 1999. It has undergone six years of research and discussion.

MPEG-1 is used to transmit the moving image of digital storage media with 1.5Mbps data transmission rate and its accompanying audio. After compression by MPEG-1 standard, the video data compression rate is 1/100-1/200. The audio compression ratio is 1/6.5. MPEG-1 provides 352 x 240 resolution images at 30 frames per second, with near-home video format (VHS) videotapes when using the appropriate compression technology. MPEG-1 allows over 70 minutes of high quality video and audio to be stored on a single CD-ROM disc. VCD uses the MPEG-1 standard, which is a video and audio compression standard for home TV quality.

MPEG-2 is mainly for the needs of high definition television (HDTV), with a transmission rate of 10 Mbps, compatible with MPEG-1, and suitable for encoding range of 1.5-60 Mbps or higher. MPEG-2 has a resolution of 30 frames per second at 704*480, which is four times faster than MPEG-1. It is suitable for demanding broadcast and entertainment applications such as DSS satellite radio and DVD, and MPEG-2 is twice the resolution of home video format (VHS) videotape.

The MPEG-4 standard is an ultra-low-rate moving picture and language compression standard for real-time image transmission with a transmission rate lower than 64 kbps. It can cover not only the low frequency band but also the high frequency band. Compared with the previous two standards, MPEG-4 provides a broader platform for multimedia data compression. It defines more of a format, an architecture, rather than a specific algorithm. It can fully use a variety of multimedia technologies, including some of the tools and algorithms of compression itself, as well as technologies such as image synthesis and speech synthesis.

MPEG-4 has attracted widespread attention since its inception. Although not everyone knows its specific goals, it has placed great hope on it. The biggest innovation of MPEG-4 is to give users the ability to build systems for their applications, rather than just using fixed standards for applications. In addition, MPEG-4 will integrate as many data types as possible, such as natural and synthetic data, to enable expression representation of content interactions supported by various transmission media. With MPEG-4, it is possible for the first time to build a personalized audiovisual system.

The MPEG-7 standard is called the "Multimedia Content Description Interface" and provides a standardized description of all types of multimedia information. This description will be relevant to the content itself, allowing fast and efficient querying of users. data of. It will extend the limited capabilities of existing content-aware solutions, especially as it includes more data types. In other words, MPEG-7 specifies a standard set of descriptors for describing various types of multimedia information. The standard was introduced in October 1998.

MPEG-21 is the latest development level of MPEG. It is a standard that enables users to transparently and widely use multimedia resources through heterogeneous networks and devices, with the goal of creating an interactive multimedia framework. The MPEG-21 technical report presents a future multimedia environment scenario that supports a wide range of application areas where different types of digital content can be used and transmitted by different users. It can also be said that MPEG-21 is a technical standard for implementing digital multimedia content with intellectual property management and protection capabilities.