Technology: How to transmit 4K network video at 1 Gbps

With the increasing resolution of video, the market has put forward more requirements for the transmission and exchange of high-definition video. For the transmission and exchange of such high-definition video, bandwidth is the first bottleneck to be broken.

　　 Transferring HD video such as 4K or Ultra High Definition (UHD) requires very large network bandwidth. 4K video (2160p60) requires 12 Gbps of bandwidth for full-color and uncompressed transmissions, while full-color 1080p video requires only 3 Gbps of bandwidth for transmission at 60 frames per second. It can be seen that 4K, the future professional video resolution, faces many obstacles in the allocation transmission.

　　 The biggest reason for these obstacles is that current network standards can hardly match the corresponding bandwidth requirements, especially when HD video is allocated more than one room. Transmission of uncompressed 4K video is extremely demanding on cables, and may even require the use of optical fibers, which results in a significant increase in the installation cost of the transmission system. Even more troubling is the fact that current distribution transmission technologies (Gigabit Ethernet, 10 Gigabit Ethernet, 3G-SDI or HDBaseT) are unable to achieve full color sampling at 2160p60 resolution. 1 Gbps Gigabit Ethernet (GbE) and 2.97 Gbps 3G-SDI can't even support full-color uncompressed 1080p60 video transmission.

*The table below lists the bandwidth required for uncompressed normal HD and Ultra HD video transmissions at different resolutions, pixels, frame rates, and color sampling rates. Most HD video requires more than 1 Gbps of bandwidth.

If you want to use existing distribution and switching technology to transmit high-definition video, you should consider a certain degree of compression of the video. For example, with the JPEG2000 compression standard and reasonable settings, the bandwidth occupied by video after compression will be greatly reduced, not only in the existing standard cable, but also through the user's existing IP network.

When it comes to video compression in professional applications, people are usually worried about the imaginary delay (that is, the time difference between the original signal and the playback terminal) and the inferior picture. These associations are mostly caused by major online streaming websites. In order to transmit video to thousands of users in various networks, streaming media websites often use MPEG2, MPEG4 or H.264 format video, and the network bandwidth requirements are low. Therefore, the video is required to be highly compressed. However, in a more controlled professional environment, compressed video can also be combined with high-definition and low-latency by carefully selecting and applying compression technology.

To understand the impact of compression technology on latency and image quality, you should first understand the principle of distribution and transmission of network audio and video. When performing IP video transmission, the video must first be "encoded" to convert the video signal into a network-recognizable digital signal. When the signal is transmitted to the playback terminal, the signal is "decoded", that is, the network digital signal is converted back to the video signal, and finally displayed through the television or the projector. The entire video transmission process covers four steps, each of which affects the video terminal delay.

It’s a good idea to use airplane flights to describe the video transmission process. The first step of the code is like boarding, and the target video is sent to the network. The second step of the transmission transmits the signal from the source device to the terminal device, which is the entire voyage of the aircraft. The decoding of the third step is to disconnect the network signal, which will be converted into a video signal. The last step of playback is like a passenger picking up their luggage and leaving the airport.

The playback speed involved in this is a frequently overlooked part of the entire video transmission allocation process. Even if the entire video transmission process is extremely powerful, as long as the display cannot perform fast pixel restoration, it may cause delay in video playback. Most monitors have a "game" mode (different from different vendors) that can restore video images more quickly and minimize latency.

Unlike real airplane navigation, the “voyage” (transmission speed) of the video is the shortest link in the whole transmission process. The transmission delay of most network audio and video technologies is shorter than that of one frame. The compression in the encoding process (and decompression in the decoding process) is the most critical factor affecting video quality and latency.

JPEG2000 (applied to the AMX SVSI N2000 series) and line-based wavelet compression (LBWC for the AMX SVSI N1000 series) enable frame compression or intraframe compression without the added latency of traditional multiframe compression. In addition, JPEG2000 supports the Tiling technology, which divides images into blocks for transmission. With JPEG2000 compression and tiling technology, the latency of compressed video can be reduced from 32-50 milliseconds to 10-15 milliseconds for full frames.

Low-latency, high-fidelity codec technology delivers high-quality video at network bandwidths of less than 1 Gbps. When the video meets the existing bandwidth requirements, video transmission and exchange can be realized by using the existing enterprise IP network, that is, users can transmit professional-quality high-quality video by using the existing network infrastructure, which will greatly reduce The cost of the entire system, simplifying the system installation process, giving the system better scalability.

SVSI's 4K video uses JPEG2000 codec technology and can be easily transmitted without 1Gbps bandwidth. Combining this codec technology with the tiling technology not only gives the video high quality picture quality, but also reduces the delay to less than one frame. In fact, the high-quality video effects brought by JPEG2000 have made this codec technology widely available in major movie studios, television networks, and even the Library of Congress.

Combining low-bandwidth transmission technology with high-quality codec technology, professional-grade high-quality video can also achieve distributed transmission over campus in a low-cost manner.

Anisotropic Ferrite Magnet Rotor

Anisotropic Ferrite Magnet Rotor,Magnet Rotor,Permanent Magnet Rotor,Impeller Assembly Magnet Rotor

HU NAN YUBANG MAGNETIC MATERIAL CO.,LTD , https://www.ybmagnet.com