SDI: Definition and Meaning 

SDI or Serial Digital Interface refers to the standard format through which delivery of any digital video takes place using coaxial cable. SDI supports data speed up to 3 Gbps. You need a standard 75-ohm cable to let SDI operate on your home TV installations. 

It is included in types of common digital video interfaces like SDI, HD- 12G-SDI, SDI, 3G-SDI, and 6G-SDI—widely in use in the broadcast and TV industry. 

SDI: Needs and Purposes 

The primary function of SDI (Serial Digital Interface) is to transmit uncompressed and unencrypted digital video signals in TV studios. But it is also used for various other broadcasting purposes including some technical operations as well. 

How much speed does SDI offer? 

SDI can offer speed up to 3Gbps but usually, it offers to speed up to 270 Mbps. However, some of the latest SDI (released after 2015) can give you speed up to 12-GBPS. 

Can I use my PC without SDI? 

Yes. You can. You need SDI only when you want to watch TV. 

Why is SDI used for? 

SDI is used to transmit signals in an uncompressed and self-synchronised format. It helps in transmitting the signal from the transmitter to the receiver in the least possible time.

The standard it follows helps in utilizing the data words, which are 10 bits in length. SDI signals can have 1–4 independent digital audio signals along with video signals. Right now, SMPT 2110 is the most acceptable standard format for SDI on IP networks.

History of SDI 

The SDI video standard got its existence for the first time in 1989 when SMPTE (Society of Motion Picture and Television Engineers) invented it to enhance their audio-visual quality.

Thereafter, its quality kept on getting better and better. 1998 is crucial in this regard as High Definition SDI was launched for the first time in history in the same year. 

What is the difference between HDMI and SDI? 

Technically, both HDMI and SDI are used for transmitting uncompressed audio and video signals. However, there’s a slight difference between these two terms. 

HDMI is famous for connecting Blue-ray DVD players and other audio-video streaming devices like video game consoles, Xbox, and others. It offers high-quality resolution up to 10k to 120 hz. Most HDMI cables can support up to 40 feet. It costs much lower than SDI. 

On the other hand, SDI is used mainly by broadcast professionals and sound engineers. It is quite expensive. An SDI cable can support up to 96 feet. It has been in use since the late 90s. 

What are SDI standards? 

SDI standards refer to the various versions of SDI available in the market. 

SD-SDI (SMPTE 259M), ED-SDI (SMPTE 344M), HD-SDI (SMPTE 292M), Dual Link HD-SDI (SMPTE 372M), and 12G-SDI (SMPTE ST-2082) among others are some of SDI popular standards.