MPEG-4 coding technology
MPEG-4: MPEG-4 is a program suitable for low transmission rate applications. MPEG-4 is developed on the basis of MPEG-1 and MPEG-2, and is designed to play high-quality streaming media. Specifically designed for video, it can use a very narrow band, compress and transmit data through frame reconstruction technology, in order to use the least data to obtain the best image quality.
The MPEG-4 standard is based on the encoding method of the object and content. It is different from the traditional image frame encoding method. It only processes the difference elements between image frames and discards the same image elements, thus greatly reducing the volume of composite multimedia files. , So you can get high-definition restored images with a smaller file size. In other words, for the same original image, the MPEG-4 coding standard has a higher compression ratio.
H.264 encoding technology
H.264 is a video encoding and decoding technology standard jointly developed by ITU-T and ISO International Organization for Standardization. H.264 is a high-performance video encoding and decoding technology.
The biggest advantage of H.264 is that it has a high data compression ratio. Under the same image quality, the compression ratio of H.264 is more than 2 times that of MPEG-2 and 1.5 to 2 times that of MPEG-4.
An original file is a video with a size of 102G. After H.264 encoding, it becomes 1G, and the compression ratio reaches 102:1. Therefore, the low bit rate technology of H.264 plays a vital role.
While users obtain high-quality and smooth images, it greatly saves download time and data traffic, and also greatly reduces image storage space.
H.264 is established on the basis of MPEG-4 technology. Its coding and decoding process mainly includes five parts: inter-frame and intra-frame prediction (Estimation), transform (Transform) and inverse transform, quantization (Quantization) and Inverse quantization, loop filter (Loop Filter), entropy coding (Entropy Coding).
After years of development of video surveillance technology, the surveillance picture is undergoing from the initial D1 standard definition image to the 4K HD and 8K ultra-clear era. The improvement of front-end pixels has brought tremendous pressure to video transmission and back-end video storage. Under the same encoding and compression ratio, users need to invest more equipment and funds. Therefore, the development of codec technology has also advanced by leaps and bounds in recent years. Due to the high compression performance of H.264, the mainstream video currently on the market basically adopts the H.264 standard.
Features and advantages of H.264
1. Low bit stream: Compared with compression technologies such as MPEG2 and MPEG4 ASP, under the same image quality, the data volume compressed by H.264 technology is only 1/8 of MPEG2 and 1/ of MPEG4. 3.
Obviously, the adoption of H.264 compression technology will greatly save users' download time and data traffic charges.
2. High-quality images: H.264 can provide continuous and smooth high-quality images (DVD quality).
3. Strong fault tolerance: H.264 provides the necessary tools to solve errors such as packet loss that are prone to occur in an unstable network environment.
4. Strong network adaptability: H.264 provides a network adaptation layer, so that H.264 files can be easily transmitted on different networks (such as the Internet, CDMA, GPRS, WCDMA, CDMA2000, etc.).
Extended reading:
H.265 coding technology
H.265 technology is a new video coding standard developed by ITU-T VCEG after H.264. The H.265 standard revolves around the existing video coding standard H.264, retaining some of the original technologies, while improving some related technologies. The new technology is used to improve the relationship between code stream, encoding quality, delay and algorithm complexity to achieve the optimal setting. Due to the optimization of the algorithm, H.264 can realize SD digital image transmission at a speed lower than 1Mbps, while H.265 can realize 720P (resolution 1280*720) ordinary high-definition audio and video transmission with a transmission speed of 1 to 2Mbps.
Currently, H.265 has become the mainstream video coding and decoding technology. Compared with traditional H.264, H.265 has a 50% lower code rate and higher compression ratio.
H.265 is designed to transmit higher-quality network videos under limited bandwidth, and can play videos of the same quality with only half of the original bandwidth. The H.265 standard also supports 4K (4096×2160) and 8K (8192×4320) ultra-high-definition video. It can be said that the H.265 standard allows network video to keep up with the "high resolution" of the display screen. As an expert in audio and video IP-based transmission solutions, Qianshi has both H.265 or H.264 audio and video transmission solutions.
H.266 encoding technology
With the growth of global Internet video demand, MPEG is promoting the development of H.266/VCC and two other standards. The first part of MPEG-5 is also called basic video coding (EVC), and the second part is also called low complexity enhanced video coding (LCEVC).
The H.266 multifunctional video coding codec standard, the new H.266/VCC codec, while maintaining the same definition, greatly improves the data compression efficiency and reduces the data volume by 50%.
H.266 will reduce data requirements by approximately 50%. Using the previous HEVC codec, transmitting a 90-minute ultra-high-definition (UHD) video requires approximately 10GB of data, while H.266 only needs 5GB to do this. H.266 is mainly used for 4K and 8K streaming video. It will allow users to store more high-definition videos and reduce the amount of data on mobile networks.