Ultra-low-latency audio-visual transmission technology based on network IP is the core technology in the professional-level audio and video field. Its purpose is to use standard network facilities to achieve real-time transmission of audio-visual signals and control the end-to-end delay at the millisecond level. This technology has completely changed the traditional audio and video system that relies on proprietary point-to-point wiring. It provides a key solution for scenarios that require real-time interaction. It is playing an irreplaceable role in medical teaching, on-site production, financial transactions, and industrial control.
What are the main technical challenges in achieving ultra-low latency AV over IP?
Achieving ultra-low latency transmission is not an easy task. The first challenge lies in the network itself. Data transmission in standard IP networks will go through routing, switching, and possibly queuing. These conditions will lead to the occurrence of delay jitter. This is a fatal problem for applications that require frame-level or even sub-frame-level synchronization. Secondly, the process of encoding and decoding video and audio signals takes a lot of time, especially when processing 4K/8K high-resolution content. Complex compression algorithms are likely to cause unacceptable delays.
Comprehensive measures are required to resolve these problems. In terms of network, strict quality of service policies must be implemented, audio and video data streams must be assigned the highest priority, and sufficient bandwidth must be ensured. In the field of encoding, it is necessary to choose options such as JPEG XS, a "middleware" compression codec specially built for low latency, minimizes processing delays while maintaining visual damage. In addition, it uses the PTP protocol that supports accurate clock synchronization to ensure that all distributed devices operate cooperatively at the microsecond level. This is also the key to eliminating audio and video desynchronization.
What are the specific differences in latency requirements for AV over IP in different industries?
Different application scenarios have greatly different tolerances for delay. In the medical field, especially in robot-assisted surgery and remote surgical teaching, delay requirements are the most stringent and must be less than one frame, which is usually as long as 16.7 milliseconds. Any delay that can be perceived is very likely to cause operation errors or distortion of teaching information. During the production of radio and television live broadcasts and live events, directors and technical supervisors need to monitor and switch multiple signals in real time. The end-to-end delay is generally required to be within a few frames to ensure that the instructions and the picture can be synchronized.
In comparison, enterprise video conferencing and remote collaboration can tolerate slightly higher delays, generally in the range of 100 to 300 milliseconds, to maintain the natural flow of conversations. However, non-interactive applications such as digital signage and information release are extremely insensitive to delays, and seconds-level delays are usually acceptable. Understanding these differences is the basis for selecting appropriate technology paths when designing a system, preventing overinvestment in insensitive applications or selecting substandard technologies for critical applications.
What are the mainstream low-latency AV over IP standard protocols currently on the market?
There are many protocol standards competing with each other in the market, each with different emphasis. SDVoE (Software-Defined Video Ethernet) is based on 10G Ethernet. It can support transmission of up to 8K resolution, and can also achieve lossless, zero-frame delay transmission effects. It natively integrates KVM functions, which is particularly suitable for high-demand environments such as command and control centers. NDI (Network Device Interface) has a wide range of applications. Its NDI high-bandwidth mode can provide high-quality 4K streams, and the end-to-end delay can be less than 1 frame. Its ecosystem is very large, and its support in terms of software and hardware is extremely rich.
The SMPTE ST 2110 standard was derived from the broadcast industry. It supports uncompressed or JPEG XS lightly compressed video streams, pursuing ultimate quality and low latency, but usually requires a more professional network environment. IPMX (Internet Protocol Media Experience) was developed on this basis. It is a set of open standards that inherits the advantages of ST 2110 and adds support for functions required by the professional AV industry such as HDCP. It aims to solve interoperability issues between devices from different manufacturers.
How to select and design a low-latency AV over IP system architecture for a specific project
In order to design a low-latency AV over IP system through reverse derivation from project requirements, we must first clarify the core indicators, such as the highest required transmission resolution, such as 4K60 4:4:4, and the maximum acceptable end-to-end delay, such as sub-frame level. The final scale of the system, that is, the number of input and output nodes, must be clarified. For example, for a 640-channel 4K zero-latency system, the core switching layer may have to adopt a 100G spine-leaf network architecture to ensure non-blocking.
The key to success or failure lies in the network foundation. You must plan a dedicated 10 Gigabit Ethernet, or plan a 10 Gigabit Ethernet with strict service quality guarantees. You must also choose a professional managed switch that supports IGMP snooping, and a professional managed switch that supports traffic shaping and other functions. In terms of encoding technology selection, if the network bandwidth is sufficient and the delay requirements are extreme, then you can consider lossless solutions such as SDVoE. If you need to transmit 4K on a 1G network, you need to use advanced compression technology. In addition, a centralized management and control software is critical for monitoring flow status, configuring routing, and quickly troubleshooting. What needs to be pointed out in particular is that professional procurement channels such as the global procurement services provided for weak current intelligent products can help integrators obtain a variety of network switches with proven compatibility, as well as codecs and management systems required to build this system in a one-stop manner, thereby achieving the purpose of reducing integration risks.
In medical scenarios, on-site production scenarios, and in critical situations, what successful application examples exist for low-latency IP-based audio and video?
In the medical field, low-latency AV over IP is revolutionizing surgical teaching and collaboration. For example, the IRCAD Surgical Training Center in France uses this technology to transmit 3D laparoscopic surgery images without delay to the teaching auditorium in real time. Students can use 3D glasses to obtain an immersive perspective that is nearly synchronized with that of the surgeon, which greatly improves the training effect. Within the hospital, this technology can seamlessly integrate signals from operating rooms, imaging departments and consultation centers to achieve high-quality remote consultation and teaching.
In the field of live production and broadcasting, this technology achieves IP-based and distributed deployment of the production process. For example, with the help of hardware encoders that support SRT, NDI and other protocols, multiple camera signals distributed throughout the venue can be transmitted to the remote production center via 5G or optical fiber network with a delay of less than 100 milliseconds for guidance and packaging processing, and then distributed to various platforms. This greatly reduces the complexity and cost of on-site deployment. In large theaters, the technical team can also pay attention to the ultra-low-latency images of each camera position and link through the Internet in real time to ensure that the performance goes smoothly.
In what direction will low-latency AV over IP technology develop in the future?
Future development will revolve around higher efficiency, stronger intelligence, and deeper integration. With the emergence of 8K and above resolution content, next-generation codec technology such as the more efficient JPEG XS will become important, and AI-based intelligent compression technology will become important, which can process massive amounts of data with extremely low latency. Open standards and interoperability will become mainstream trends. Open frameworks like IPMX aim to break down vendor barriers, enable plug-and-play for different devices, and reduce system integration complexity.
The deep integration of artificial intelligence into the system will achieve automatic traffic optimization, fault prediction, and content-based intelligent routing. In addition, the integration with the Internet of Things and 5G will open up new scenarios. For example, the 5G network can achieve broadcast-quality wireless low-latency transmission, bringing revolutionary changes to outdoor live broadcasts and mobile production; AV systems will also be more closely integrated with building automation systems to form intelligent environment-aware networks.
Regarding your industry field, when deploying low-latency AV over IP systems, do you think the biggest obstacle is not technical, such as budget approval, team skill transformation, or department collaboration, etc. What exactly is it? I hope you can share your actual experiences, knowledge and opinions in the comment area.
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