In the field of SONY industrial camera, Shenzhen Xuanzhan technology has been deeply engaged in 14 years, as the authorized agent of SONY integrated movement, for the camera HDMI interface and HD-SDI interface, must be more familiar with, today to share with you their functions and differences, I hope to help you.
1. What is SDI?
SDI’s full name in English is “Serial Digital Interface”, and its Chinese name is serial Digital Interface.
A serial interface is an interface that transmits each bit of a data word and the corresponding data sequentially through a single channel. Because of the high data rate of serial digital signals, they must be processed before transmission. Scrambled non-return to zero inversion (NRZI) is used to replace the earlier block coding. The standards are SMPTE-259M and EBU-Tech-3267, which include digital composite and digital component signals including digital audio.
2. SDI video transmission line
SDI is a professional video transmission interface, which is generally used in broadcast video equipment. Both SDI and HDMI support uncompressed digital video transmission, but HDMI requires 19 cables to transmit, while SDI uses a normal 75 ohm coaxial line. HDMI is currently long and can only transmit 40 meters, while SDI can transmit 120-400 meters.
HDMI Its full name in English is High Definition Multimedia Interface, Chinese interpretation is high definition multimedia interface, support HDCP, mainly used in consumer electronic products.
HDMI is an older digital interface that supports full digital high definition, multi-channel audio and intelligent format and control command data over a single cable without compression. HDMI interface is advocated by SiliconImage and developed by a working group jointly established by SONY, Hitachi, Panasonic, Philips, Thomson, Toshiba and other eight famous consumer electronics manufacturers.
HDMI’s earlier interface specification, HDMI1.0, was released in December 2002, and the current higher version is the HDMI1.3 specification, released in June 2021. As an HDMI interface, it can provide data transmission bandwidth of up to 5Gbps, and can transmit uncompressed audio signals and high-resolution video signals. At the same time, it does not need to carry out digital/analog or analog/digital conversion before signal transmission, which can ensure high quality audio and video signal transmission.
Compared with DVI, HDMI can be regarded as the strengthening and extension of DVI interface. HDMI can transmit digital video signals at the same time as digital audio signals (that is, audio/video using the same cable), and increases support for HDCP, while providing better DDC optional functions.
4. HDCP is High-bandwidth
Short for Digital Content Protection, High bandwidth Digital Content Protection (HDCP) is an encryption technology designed for high-quality movies to prevent movie data from being copied between the computer’s digital video output (DVI or HDMI) and the display.
HDCP technology was developed by Hollywood in cooperation with Intel, the semiconductor giant. It can be used in the transmission end of graphics cards and DVD players, as well as the receiver end of monitors, televisions and projectors. It is an important anti-piracy technology for high-definition movies and TV programs. Displays that do not support HDCP cannot normally play high-definition programs with copyright.
5. HDMI video transmission cable
HDMI and SDI applications are different, there will be no conflict, HD-SDI can only do 1080I, now the newer version is 3G-SDI, can do 1080P. HDMI can output 2160P.
HDMI transmission cable
After the above detailed explanation, we can be very clear:
a. For HD cameras, 3G-SDI interface and HD HDMI interface coding control board are applicable, users can choose according to their own needs, such as SONY’s popular calibur FCB-EV9500L, FCB-EV7520, FCB-EV7500, FCB-EV7100, etc. Two kinds of interface control board can be selected;
b. For 4K UHD cameras, such as FCB-EW9500H, FCB-ES8230, FCB-ER8530, etc. Due to the limitation of 3G-SDI interface, only 4K HDMI coding control board can be used at present.