About Video Conferencing


Video conferencing was a vital method of communication during the COVID-19 pandemic, but its roots go back much longer than you think.

Featuring Tom Merritt.



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Episode transcript:

Too soon? I know, but bear with me. Because among all the other unprecedented first time in history moments we experienced over the last few years, the boom in video conferencing was one of the biggest. Use of video conferencing to conduct meetings skyrocketed in 2020. With Zoom alone going from an estimated 10 million daily meeting participants in December 2019 to 300 million by April 2020.
You’d almost think Zoom invented video conferencing. But of course we all know that Skype predated Zoom. And Webex and others predated those. In fact, the roots of video conferencing go pretty far back.
That’s Douglas Engelbart demonstrating his version of video conferencing in the Mother of All Demos in 1968. Pretty far back right? It was one of the many elements of that demo that became a real product. Maybe faster than you think. AT&T launched the first true video-conferencing system on June 30, 1970. Which means I’m two days older than video conferencing. Anyone could subscribe to AT&T’s service in their home or office. If you had the money.
But the roots of video conferencing go even farther back. As soon as the telephone was patented in 1876, people began imagining telephonoscopes and electroscopes, and video telephones. Reality lagged a little behind their imagination.
Ernest Hummel was able to transmit still images using his Telediagraph as early as 1895. It was limited to images that could be made in shellac on foil, but it was something. By 1913, Édouard Belin’s Bélinographe used a photocell and by 1921, Western Union had launched the Wirephoto service which could transmit photos over phone lines. These took more than a minute per image so no video.
One-way video came along as television. But it took until 1930 for AT&T to develop a “two-way television-telephone” system. The systems were not terribly practical though, transmitting low resolution black-and-white video over telephone lines. And they were basically a series of still images not video.
AT&T was trying to figure out how to do this over its copper phone lines. But you didn’t have to use phone lines.
Dr. Georg Schubert developed the first public video telephone service using coaxial cable, the cylindrical cables most people are familiar with from cable TV. It launched March 1, 1936 connecting two closed-circuit televisions by coaxial cable in post offices in Berlin and Leipzig, Germany, about 160 km apart. It had 150 lines of resolution at 25 frames per second. 150p! And it worked. By 1938, Berlin, Leipzig, Hamburg, Nuremberg and Munich each had two video telephone booths in their main post office. If two people wanted to video call each other, they would each visit one of the booths at their post office at the same time. There were plans to expand further but those ended with the start of the war in 1939, and the system was shut down in 1940 so it could be used for telegraph and broadcast TV considered more essential to the war effort. A similar post-office based system was built in France in the 1930s as well.
Meanwhile AT&T kept working on videophones over telephone lines. The Picturephone Mod I used a small oval case on a swivel stand to house the screen. AT&T demonstrated The Mod I at the New York world’s fair in 1964 by making a video call to Disneyland in California. AT&T opened its first public videophone booths later that year, with First Lady, Ladybird Johnson doing the inaugural honors. In New York, Washington DC and Chicago, each participant in a call could reserve a time and visit the booth to make their call. Calls cost $16 to $27 for three minutes. That would be $150-$260 in 2023. It was too expensive. And the booths closed in 1968, the same year Douglas Engelbart demonstrated his computer-based video conferencing in the mother of all demos.
AT&T took up that cue and launched Mod II in 1970. This was more like a videophone. Anyone could be connected to the system, you didn’t have to visit a dedicated booth. Pittsburgh Mayor Peter Flaherty made the first Mod II video call on June 30, 1970 to Alcoa CEO John Harper. Service launched the next day, July 1, 1970 with 38 picture phones located across 8 companies in Pittsburgh. A set cost $150 to install and $160 a month to use and additional sets could be added for $50 a month each. You got 30 minutes of calling per month with extra minutes costing 25 cents a minute. Resolution was 250 scan lines of black and white video. Customers for the service peaked at 453 in early 1973 and it was discontinued later that year.
Compression Labs is often seen as an AT&T competitor that picked up that baton but it was even more expensive. In 1982, it launched the CLI T1, the first commercial group video conferencing system. It cost $250,000 to install and each call was $1,000 an hour.
And that still wasn’t digital video conferencing. It was still just a phone call with video shoehorned in.
To do digital you needed digital video compression and to do digital video compression you need math.
Anil K. Jain was born in India in 1946, as the war that had shut down Germany’s big videophone experiment ended. Jain received a degree in electrical engineering at the Indian Institute of Technology, in 1967 and a PHD from the University of Rochester in 1970, the year AT&T launched its videophone. Jain would develop the math that would mean you didn’t need these dedicated units. He worked on transform coding, image compression and block-based motion compensation for video compression. And video compression meant all you needed was a camera and the internet to do what these big expensive systems in Germany and at AT&T were trying to do.
By 1981, Jain was at the University of California at Davis and published a paper combining his block-based motion compensation with transform coding. That paper inspired two students at MIT, Brian L Hinman and Jeffrey G. Bernstein to work on a way to compress video so it could be used over the internet. By 1984 they, with their professor, David H. Staelin, they founded PicTel. Later renamed PictureTel to distinguish it from Pacific Telephone Company, aka PacTel. Its first product was a video codec, the C-2000, the first commercial implementation of a compressor/decompressor of its kind.
Building on Jain’s math, C-2000 analyzed the motion between frames meaning it could work with much less data than an algorithm that treated each frame of video independently. Remember all those slowly transmitted still images of the early 20th century? To oversimplify the C-2000 let you get by on fewer still images and make up what came between so it looked like smooth video motion. In practice that meant you could do video over a 128-bit-per-second ISDN line instead of needing fixed location lines.
Most video compression standards for two-way video are based on this motion compensation and transform coding way of doing things, including the pervasive H.264 codec. PictureTel marketed its codec and eventually used it in its own software, including LiveSharPlus for Windows 3.1 And PictureTel did well. In fact AT&T used it for an international video conference in 1989. Hinman went on to found a separate teleconferencing company called Polycom in 1990, and Polycom bought PictureTel in October 2001.
The next step for video conferencing was the camera. The pioneers in this were motivated by coffee.
Yes the British drink coffee. And at the Cambridge computer lab in 1991, the coffee machine was in a separate room. Many were the agonies of a computer lab user trudging all the way to the Trojan coffee room, only to find it empty.
Quentin Stafford-Fraser and Paul Jardetzky had a solution. They connected a video capture card to an Acorn Archimedes computer and a 128 x 128 greyscale camera and pointed it at the coffee pot so you could check if it was worth the trip. At first it was delivered to the local network but in 1993, web browsers gained the ability to display images, so the camera was connected to the internet to make it easier to access on any computer in the lab… and the world. Daniel Gordon and Martin Johnson made it available over HTTP, thus making it the first webcam.
But that was still not two-way video. So here we go again. Another technician in a college saves the day.
Tim Dorcey worked in IT at Cornell University and used the new video codec and Internet Protocol system to write CU-SeeMee for the Mac in 1992. You could put it on any machine and connect to any other machine that used it over the internet. That way you didn’t have to set up a server for your video. Just install the software and start calling! It only did video at first but added audio in 1994 thanks to Maven, a client developed at the University of Illinois.
A National Science Foundation project called Global Schoolhouse made CU-SeeMee available to the public on April 26, 1993. CU-SeeMe was used by WXYC radio in Chapel Hill, North Carolina, to simulcast its radio broadcast on the internet, making it the first internet radio station.
ABC’s World News Now became the first TV program to stream live on the Internet on November 23, Thanksgiving morning, 1995.
And that’s really the last step. Some innovative math and a smart codec implementation meant you didn’t need huge specialized machines, just a server, a bit of coffee-motivated ingenuity meant you didn’t need a big expensive camera, and some clever software coding meant you didn’t even need the server. From here on video conferencing exploded.
Microsoft entered the game with NetMeeting and as bandwidth increased, the amount of video conferencing software from Skype to GoToMeeting and beyond, increased with it.
So much so, that Eric Yuan had a hard time getting funding for his startup Saasbee when he left Cisco in 2011. Not because of the name, but because everybody thought the market was saturated. Yuan eventually prevailed on a few folks and in May 2012, reportedly influenced by the children’s book Zoom City, he changed the company’s name to Zoom. It took a few years but things worked out for Yuan.
And now many of us work, using Zoom, or some other kind of video conferencing technology. I hope this gives you some of the historical perspective of how we got to this world of working from home and Zoom fatigue.
In other words, I hope you Know a Little More about Video Conferencing.