SDI over IP solution may become the trend in future TV transmission system
The digital and network upgrade in TV stations has entered the area of multimedia and ultra-high definition. With the development of ultra-high definition technology such as integrated media and 4K, the bandwidth and cable problems needed for transmission from digital broadcasting and television to program production and broadcasting become more and more prominent. The existing technical framework of TV stations based on SDI baseband video interface and special SDI digital video matrix has been difficult to meet current requirement.
SDI signal as a transmission standard of high-definition digital video by coaxial cable has certain advantages when TV stations are still in the area of standard definition or high-definition (1080P). However, in the coming ultra-high definition (4K and 8K), the continued use of traditional SDI signals will bring a series of problems. Cables are numerous and difficult to maintain, since one SDI cable on matrix switcher can only carry one channel of SDI TS signal. There are hundreds or even thousands of SDI cables in the TV station, which are long and bundled together, once the cable breaks down, the TV station is not easy to maintain, and the expansion cost is high. Even now some TV stations have used SDI fiber optic extender to transmit SDI signals over fiber optic cable. But now it is not flexible enough.
So, more and more TV device manufacturers keep trying to develop products and solutions based on shallow compression IP or non-compression IP system. Compared with SDI over fiber or coax, the advantages of IP are: wide coverage of IP network, mature transmission technology; simple wiring, reusable equipment; saving investment compared with traditional equipment; and IP signal compression and coding mode is very mature, upstream and downstream services and related equipment are also accelerating the process of IP. All these have led to the IPization of the whole station will become the trend of the future development of television media.
At present, Sony is always in the leading position in the field of IP-based live video production applications. At the 2015 NAB exhibition, Sony demonstrated an advanced 4K "live over IP" solution for live broadcasting. The core of this solution is the world's first live production switchboard with 4K and IP network functions, which allows users to choose the type of input/output slot connected to each device - IP or SDI. In this way, each TV station can flexibly configure its own devices, only IP, SDI, or IP and SDI mix. It also allows broadcasting and television users to continue to use existing SDI device assets in the process of upgrading to IP mode.
In this scheme, a 40GbE fiber-optic Ethernet cable transmits multiple 4K and HD video streams from the camera area of Sony's booth. The video stream from the camera is converted from SDI interface mode to IP interface mode by NXL-FR318 signal processing unit (with NXLK-IP40TSDI-IP conversion board). The 4K field switching station can carry out mixed switching of IP and SDI signals. This system has interrupt switching function, which can avoid signal interruption when IP switching failure occurs. At the same time, PWS-100NM1 IP field management software workstation can be used to operate these devices. Sony's unique algorithm and QoS technology allow users to choose the optimal network bandwidth to ensure the security and stability of 4K sign. Now more manufactures have SDI over IP solutions and devices. The system cost will be reduced for TV station upgrade