HD-SDI- the Basics
HD simply stands for High Definition. SD or Standard Definition is what is used to define standard definition visual displays. SDI stands for Serial Digital Interface, and essentially refers to the cables. HD-SDI is now the most common form of display and audio configuration for modern televisions and security cameras.
SDI – All the Way Back to 1989
SDI was developed by The Society of Motion Picture and Television of Engineers in 1989 for the standardization of broadcast-grade video. While the standards are ever-evolving, the fundamental and basic principles remain fundamentally unchanged. Data is condensed into code, the code is integrated into the standards of the hardware and software, sent through the system(and the cables) to the display, and converted back into the original broadcast (DVD, television show, security system recording, etc.).
HD Standards
The most common current standards are SMPTE 259E, SMPTE 344M, SMPTE 292M, SMPTE 272M, and SMPTE 424M. The numbers should be viewed as references. The first few are tricky. 259M translates to a Standard Definition broadcast signal or 480i. 344M is ED or enhanced definition, or a 480P broadcast. 292M the first HD broadcast standard that runs in 720P grade picture quality. 372M is a dual link (2-wire) digital interface with 1080p level quality. 424M also has 1080p broadcast quality, but is not dual link.
The Importance of Cable Speed
Owning the newest and best Blu-ray player and the best television money can buy does not necessarily mean the best picture is going to be shown if the cables are not right. In most cases the cables will come with the products, but sometimes those cables get damaged or lost, whether through moving or through an accident.
When replacing these cables it makes sense to know what is needed. Having the hardware on the front end – the cable box, game system, HD-SDI camera, Blu-ray player or HDSDI CCTV matters, but only if the connection maximizes the transfer of data needed to give the best quality picture possible.
The best parallel to draw is internet speed. Older signal standards such as standard definition required older 259M, or dial-up. Moving on we get to DSL, then cable, and moving on and up to fibre optics. Either for entertainment or security, the higher the speed the better the image can be.
The Future of HD
With the coming of commercially available 4K televisions in the news, new standards for those available definitions are being discussed. While the numerical standards of the SMPTE are not official, here is the comparison: 424M is a 3G cable transmission. 6G-UHD(Ultra High Definition)-SDI and 12G UHD-SDI transfer rates are being developed. In the future, as the need for higher and greater quality and picture is demanded, the standards will continue to evolve and the cable transmission rate will continue to rise.
About Author
Whether you are looking for an HD-SDI CCTV camera, or a number of advanced HD-SDI cameras to be used in a security setting, Jumbu is the premier choice. Jumba is an online supplier of security systems to the Australian market and with experts standing by to advise you of the best system for your specific needs.
