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May 30,
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It is known that SDI interfaces can be roughly divided into three types: SD-SDI (270Mbp, SMPTE259M), HD-SDI (1.485Gbps, SMPTE292M) and 3G-SDI (2.97Gbps, SMPTE424M). It is seen from these standards of division that the rate is an important index. For HD-SDI and 3G-SDI, as the commonly-used two types in radio and television industry, maybe there are still many people unfamiliar with them and what difference between them. Then in this article, there will be an introduction to the difference between HD-SDI and 3G-SDI.
Before the introduction to HD-SDI and 3G-SDI, to understand them better, it will be better to know what SDI is. SDI (Serial Digital Interface) is a digital video interface standard made by SMPTE organization. This serial interface transmits every bit of data word and corresponding data through single channel. Due to the high data rate of serial digital signal (a kind of digital baseband signal), it must be processed before transmission.
What Is 3G-SDI?
3G-SDI has been widely used in the radio and TV industry. With the continuous development of the security industry, its advantages, high speed and without digital uncompressed, are gradually found. At present, a large number of 3G-SDI series products have been introduced in the market, including SDI conversion equipment, SDI digital switching matrix equipment and SDI distributor. These devices use 3G signals, and can also be compatible with 1.5G signals for long-distance transmission to meet the diverse needs of users.
What Is HD-SDI?
HD-SDI is a high-definition digital component serial interface. HD-SDI is high-definition radio and television camera which is real-time and uncompressed. It is another scientific and technological progress in the security monitoring field. It provides a high-definition image source for the monitoring center. The HD-SDI camera, based on the serial link standard of the SMPTE (film and television Engineer Association), is a high-definition and real-time video camera that transmits uncompressed digital video through 75 ohm coaxial cables.
What Is the Difference Between 3G-SDI and HD-SDI
The design and production of HD-SDI optical terminal equipment is suitable for serial digital optical transmission equipment with high reliability and high performance in the TV industry. The signal format is from 19.4Mbps to 1.485Gbps, and the system supports the signals with digital TV formats such as SMPTE292, SMPTE259M, SMPTE297M, SMPTE305M, SMPTE310M and DVB-ASI (EN&#;9), so as to satisfy the requirements of industrial products. 3G-SDI digital video optical terminal device with ultra high definition is an upgraded version of the HD-SDI optical terminal device. The signal format is from 19.4Mbps to 2.97Gbps, and the system is accorded with the signal of digital TV formats such as SMPTE424M, SMPTE292M, SMPTE259M, SMPTE297M, SMPTE305M, SMPTE310M, DVB-ASI (EN&#;9) and so on.
With the emergence of standard about high-definition(HD) video standards such as i and 720P, the interface is adjusted to process higher data rate(1.485Gbps). The 1.485Gbps serial interface is usually called as HD-SDI interface, defined by SMPTE292M, and uses the same 75 ohm coaxial cable. SMPTE approves a new standard called as SMPTE424M, which doubles the SDI data rate to 2.97Gbps on the same 75 ohm coaxial cable. This new standard is also called 3-Gbps (3G) SDI, which supports higher-resolution image quality such as P and digital cinema. At present, the highest rate of digital products is 7K-SDI.
Above all is about the difference between HD-SDI and 3G-SDI. For SDI series products, Gigalight currently has 3G-SDI SFP, 6G-SDI SFP+, 12G-SDI SFP+ optical transceiver. If you want to know more details, welcome to visit Gigalight official website.
Contact us to discuss your requirements of 3G-SDI optical transceiver. Our experienced sales team can help you identify the options that best suit your needs.
About Gigalight:
Gigalight is a design innovator in global optical interconnect field. A series of optical interconnect products include: optical transceivers, passive optical components, active optical cables, GIGAC MTP/MPO cabling, cloud programmers & checkers, etc. Three applications are mainly covered: Data Center & Cloud Computing, MAN & Broadcast Video, and Mobile Network & 5G Optical Transmission. Gigalight takes advantage of its exclusive design to provide clients with one-stop optical network devices and cost-effective products.
As application scenarios such as broadcast, live events or so have an increasingly higher standard towards bandwidth, the SDI standard has witnessed contintous evolution. SDI-Serial Digital Interface, widely used in SDI encoders, SDI converters, and other equipment, which has been applied to radio and television fields, and security monitoring. including HD-SDI, 3G-SDI, 6G-SDI, and 12G-SDI, but what are they, and what are the differences though?
The SMPTE group created the SDI (Serial Digital Interface) digital video interface standard. This serial interface uses one channel to send all bits of the data word and its related data. Serial digital signals must be handled before transmission because of their high data rate.
SDI is a digital video transmission technology that is widely utilized in broadcasting, live events, and other professional settings. It employs two coaxial cords to transmit one digital signal via optical fiber at speeds ranging from 270 Mbps to 12 Gbps. The ptz SDI is a point-to-point interface, which implies that every wire transports data from one appliance to another.
The standard known as the HD Serial Digital Interface (HD-SDI) is standardized in SMPTE 292M; Although this standard is known as the 1.5 Gb / s interface, the bit rates supported by HD-SDI are actually 1.485 Gb / s and 1.485 / 1.001 Gb/s. OPTCORE provides a wide line of HD-SDI transceiversiver for the special broadcast application.
This standard defines a bit-serial data structure, electrical signal, and coaxial cable interface for the transport of signals with a total payload of 5.940 Gb/s or 5.940/1.001 Gb/s. This standard also specifies the electrical and physical characteristics of coaxial cables and connectors. This standard defines several mapping modes for the carriage -line and -line image formats and associated ancillary data into a Single-link 6 Gb/s [nominal] SDI bit-serial interface.
The 270 Mb/s data rate is supported by the SD SDI standard. SD SDI employs a clock rate of 27 MHz to deliver low-resolution PAL video at 25 frames per second. In , the ITU-R issued Recommendation BT.656-2, which included the new serial digital interface distinguished in EBU Tech. and SMPTE 259M. It uses non-Zero Reverse (NRZI) encoding and employs 10-bit transmission. It is mainly utilized for 480i and 576i video formats.
The 12G SDI is a high-resolution, enhanced frame-rate, and high-color commitment SDI standard. It has four times the capacity of HD and can send 12 Gbps, which makes it perfect for 4K 60p. It is especially utilized for p video formats at 60 FPS.
The basic electrical specifications of HD-SDI and SD-SDI are the same, but the transmission bit rate is much higher than that of SD-SDI. Since the ITU-R BT.-2 specifies that the luminance sampling frequency of high definition video signals is 74.25 MHz and the sampling frequency of two color difference signals is 37.125 MHz respectively, the basic bit rate of HD-SDI reaches 1.485 Gb / s. Taking into account that the distribution of high-frequency transmission cable parameters affects the transmission of high-definition video signals, the cable length will be greatly reduced.
The data transmission format of HD-SDI is the same as the transmission format of SD-SDI, and the luminance signal Y and the color difference signals Cb and Cr subjected to time-division multiplexing are handled as 20-bit words. Each 20-bit word corresponds to a color difference sample and a luminance sample. The multiplexing modes are: (Cb1Y1), (Cr1Y2), (Cb3Y3), (Cr3, Y4).
Here is a brief comparison table of various SDI:
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