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100GbE To Slash the Cost of Producing Live Television
New submitter danversj writes "I'm a Television Outside Broadcast Engineer who wants to use more IT and Computer Science-based approaches to make my job easier. Today, live-produced TV is still largely a circuit-switched system. But technologies such as 100 Gigabit Ethernet and Audio Video Bridging hold the promise of removing kilometres of cable and thousands of connectors from a typical broadcast TV installation. 100GbE is still horrendously expensive today — but broadcast TV gear has always been horrendously expensive. 100GbE only needs to come down in price just a bit — i.e. by following the same price curve as for 10GbE or 1GbE — before it becomes the cheaper way to distribute multiple uncompressed 1080p signals around a television facility. This paper was written for and presented at the SMPTE Australia conference in 2011. It was subsequently published in Content and Technology magazine in February 2012. C&T uses issuu.com to publish online so the paper has been re-published on my company's website to make it more technically accessible (not Flash-based)."
Well that's a failure of imagination. I'll admit technically speaking it often is *somewhat* compressed, - eg. 422 Subsampled chroma at least. But there is a massive difference between a delivery codec and a signal you're still working with. To start with H264 and their ilk are computationally expensive to do anything with. A single frame of 1080p is a pretty big dataset, and it's painful enough doing basic matrix transforms, but adding a bunch of higher level computations on top of that?... For example just cutting between two feeds of an inter frame compressed codec requires that the processor decompress the GOP and recreate the missing frames. Several of orders of magnitude more complicated than stopping one feed and starting another. And generally speaking the uncompressed feed you have in broadcast situation you're doing *something* oo. Switching, mixing, adding graphics, etc. But the biggest question is one of generation loss. Even one round trip through one of those codecs results in a massive drop in quality (as you rightly point out). You don't want to be compressing footage out of the cameras any more than you can, because you KNOW that you're going to be rescaling, retiming, wiping, fading, keying etc etc etc...
-Steve http://www.stevennicholson.com
I work in film, we usually scan 35mm 3 perf at 8k and 2 perf at 6k. Output after offline edit is usually 4k or 2k. Punters are going to be flogged re-released videos that cost the studios nothing. 1080p is more than enough for most people, unless you are going to have to have a screen large than 100 inches from 10 feet away, most people have a 32 inch TV at 15-20 feet.
TV does not work in 1080p anyway, still stuck at 1080i. Only your high-end dramas are captured with 1080p, 2k, 4k if digital (Sony F35, F65, Arri D21, Red if you don't mind downtime) or on 35mm (I haven't worked with 35mm in drama for over 5 years now).
More realistically, 4096 * 3072 * 60 Hz * 20 bits (That's 10-bit 4:2:2 YCbCr, like HD-SDI today) = 14 Gbit/s. You could push 6 of those streams over 100GbE.
> The intent here is to replace so much of the specialized cabling
Yup. I'm glad I work in radio, where we've been ferrying oversampled, high-quality audio over IP for some years now.
The digital switching and input assignments are a dream as well. Not that many years ago, if someone came into Engineering and said, "sorry, forgot! We have a paid ballgame going on at 4PM!" ... my assistants and I would literally grab a punch tool and some Belden wire and start frantically running cables. Many was the time we'd put something on air by literally throwing a pair across the floor with gaffer's tape. "Watch Yer Step!" :)
Nowadays, any source in our facility can be assigned to any input on any mixer in any control room. Run once, use many times. Ah, it's a beautiful thing. I can move an entire radio station from one control to another literally in a matter of minutes. It takes longer for the staff to physically grab their coffee cups and lucky charms than it does for my staff to move the signals.
My poor brethren in TV just have entirely too much data. If we'd all go back to RADIO drama, see, this wouldn't be a problem, now woodit? :D
Cogito, igitur comedam pizza.