I remember, years ago, looking through the SMPTE 259M standard for the Serial Digital Interface (SDI). It was a bit much to grasp at first, but we had plenty of help from industry veterans as we began to navigate what is now a very common digital video standard. Needless to say, SMPTE 259M was revolutionary for its day. The SDI standard replaced many vital pieces of analog video such as four-field color framing, vertical interval data, sync, breezeway, color burst and a slew of details that helped engineers understand a very mature video format on coaxial cable. It would take me a while before I could manipulate SDI like I did with the old analog signal.
When SMPTE 292M came along, it more or less followed in the footsteps of the SMPTE 259M standard - and before long, we were quickly adapting studio video to high definition. One of the “comfort foods” of that era was that these changes were all happening on coaxial cable, the same cable that I made connectors for when I was a junior television engineer. Fast forward to the present, where we’re working with high - speed fiber at rates that we never would have believed back in the old analog days. And, like all good things, coax will one day be completely replaced by fiber. Now, that’s a mouthful, because it’s not just a little cable switch - it’s a huge change for our industry. Like any technology change, coax signals will be adapted and moved into a technology sector we’ve all seen growing alongside studio video: Ethernet. But since there have been a few unsuccessful attempts at moving the SDI signal to Ethernet, it’s important to understand how we arrived at the present state of SDI in the industry.