With the development of high-definition network technology, the development of audio and video technology has gradually come into everyone’s field of vision, and live broadcast platforms have also sprung up. The common point between live webcast and TV live broadcast in the encoder is video transmission. All need to use video cameras or other video sources, so the data of these video source information is very large before being compressed, especially for high-definition video sources. The more high-definition equipment, the details are extremely important.
Therefore, if the video needs to be broadcast on the network, an encoder is required to compress the original huge video source to reduce redundant information, so as to realize network transmission, and then push it to the remote video server. There will be a delay in video transmission in the middle: the most important link in the stability and delay of the video encoder.
At present, the most popular high-definition video encoder is low-latency technology, high-stability transmission technology. The following focuses on sharing low-latency transmission technology applications.
Local area network NDI low-latency technology
NDI is one of the hotspots of low-latency transmission today. NDI is a low-latency, high-quality transmission protocol. KILOVIEW is the official NDI product supplier of NewTek. Combining NDI technology to develop a new product N20 4K NDI codec, supporting FULL NDI protocol, the end-to-end delay in the LAN is only 1-3 frames (about tens of milliseconds, while the traditional RTSP transmission end-to-end takes about 300 milliseconds), It is a typical representative of low-latency transmission technology in the current market. It supports 4K P60 ultra-high-definition resolution, supports Tally display and PoE power supply, and transmission requires Gigabit network environment support.
Another N-series NDI encoder that supports WIFI wireless transmission, supports the NDI HX transmission protocol, the end-to-end transmission in the local area network can achieve a low latency of more than 100 milliseconds, and the bandwidth is low (the default is about 10M). Deploy and transmit multiple NDI signals, which is very suitable for the production and transmission of multiple high-definition videos.
Internet SRT low-latency technology
SRT protocol can successfully realize the safe and reliable high-definition video transmission and distribution under the ordinary Internet environment and between multiple places. At the same time, SRT can also perform AES encryption to ensure information security during data transmission. SRT is a very popular open source low-latency video transmission protocol nowadays. SRT solves complex transmission timing problems. SRT can reduce delay, eliminate central bottlenecks, and reduce network costs.
SRT protocol features
Three major features: safety, reliability, and low latency.
In terms of security, SRT supports AES encryption to ensure end-to-end video transmission security.
In terms of reliability, SRT uses Forward Correction Technology (FEC) to ensure the stability of transmission.
In terms of low latency, because SRT is built on top of UDT protocol, it solves the problem of high transmission delay of UDT protocol. UDT protocol is based on UDP network communication protocol.
SRT solves the problem of complex transmission timing and can support real-time transmission of high-throughput files and ultra-definition video.
For example, the radio and television industry interacts with programs in different places, and returns programs from other places to TV stations. SRT Internet transmission technology is a point-to-point transmission technology that does not require a transit platform. It has the advantages of "low latency and anti-network jitter" and has been sought after by users worldwide. All the codecs of Qianshi Electronics have supported the SRT transmission protocol. The end-to-end transmission of the Internet can be controlled within 1 second, and the picture will not be flickered or stuck in the case of 20% network packet loss. Like NDI series products, SRT products are the star products of Qianshi. All products of Qianshi Electronics support SRT protocol.