Video encoding is a key parameter of high-definition network cameras, which determines the image quality of the transmitted video and the required network bandwidth. The high-definition network camera video encoding standards we currently see are mainly MJPEG and H.264.
MJPEG (Motion JPEG) is a dynamic image compression technology developed on the basis of JPEG. It only compresses a certain frame independently, and basically does not consider the changes between different frames in the video stream. Through this compression technology, high-definition video images can be obtained, and the video resolution and number of compressed frames of each channel can be flexibly set, and the compressed picture can also be arbitrarily edited. But its shortcomings are also very obvious: First, the frame dropping phenomenon is serious and the real-time performance is poor. It is difficult to complete real-time compression on the premise of ensuring that each channel must be high-definition; second, the compression efficiency is low, and the transmission bandwidth and storage space take up a lot .
H.264 is a new-generation video coding standard developed by the JVT Joint Video Working Group jointly established by ITU-T and ISO. It is used to achieve the goals of high video compression ratio, high image quality, and good network adaptability. H.264 not only saves more than 80% bit rate than MJPEG, but also has better support for network transmission. H.264 introduces an encoding mechanism for IP packets, which is conducive to packet transmission in the network, supports streaming media transmission of video in the network, and supports hierarchical encoding transmission under different network resources, so as to obtain stable image quality. H.264 can achieve 720p, 1080i / p broadcast-grade high-definition video resolution at a lower bandwidth.
Although MJPEG can get better single image quality, but because of its fatal flaws in terms of mobility, bandwidth occupation and storage space occupation, H.264 will inevitably be the main focus of high-definition network cameras in the future.
utility knife,box cutter knife,retractable utility knife,best folding utility knife
Yucheng Shuangyan Hardware Plastic Factory , https://www.shuangyanhardware.com