Live Chromakey software – PC

[Mark Suszko]

Zvi, why the insistence on keying live, that adds a lot more cost that you may not need to spend unless the shoot is truly live broadcast. Most people that need to key live I think do it with hardware, using a switcher. If they want to do a test on location for post, they might run a laptop with the Adobe scope software on it, capture a short couple of seconds and do a test matte with their SW of choice. Or just bring a portable version of their editing apps and hardware to the location. But to do the whole thing live in software, in HD may be asking for something you can’t afford. If you’re scrambling to afford the lights for this green room, you probably can’t afford the higher-end live keying software. But maybe I missed some new stuff since last NAB.

[Zvi Twersky]

Thanks.

It’s true we’re scrambling to reduce costs. The reason I wanted live is not for a final product but to get an idea of the quality of the lights. I want to get a general picture of my key while adjusting lights while not having to shoot, transfer to computer, check, re-adjust lights, transfer again, check, etc…

The shooting and transferring to computer takes up precious time that I think a good keying and composting software can spare me. Also, a program like that, although might not be cheap, will definitely be cheaper then hardware and mixers.

The Adobe idea might be ok. What Adobe product is most particular for key checking? Would it be AE with some plugin like Key Correct Pro, or just the plain keyer in Premiere or do you know of some other Adobe product that would better fit what I need?

Thanks.

[Mark Suszko]

You could record using Adobe OnLocation, and check a still using photoshop, or bring the footage into any keyer program you own.

[Zvi Twersky]

I don’t want to record. I want to glance at my monitor, see the live footage and move lights around as needed. Like looking into the viewfinder of a video camera. You see what your going to shoot before you shoot it and when you’re framed right and the lighting and color balance is ok, you press record.

About your second reply, I can’t do that because the keyers I have don’t support MP4.

Someone referred NUKE to me. Anyone had experience with it?

[Mark Suszko]

Nuke is US$3,500 plus a grand a year maintenance plan. And needs a pretty powerful computer to run smoothly. And I still don’t think that works live like the virtual switcher you’re thinking of. You’d still have to capture first, then set up the key.

You’re wanting to do something like Cameron’s Avatar setup on a Plan 9 budget.

If the realtime aspect is so darned vital, you could break out a composite video feed from the camera and run that to a Video Toaster or Tricaster and have your instant live feedback, figuring that if the key holds up okay using composite, it will do even better in post as HD. Or spend more for the new HD Tricaster, I just don’t feel the same urgency about the fully established live key for your particular needs, but then again, maybe I missed something about the kinds of work you’re going to be doing on this set? Anything more you can add in that regard?

[Zvi Twersky]

My knowledge is based on learning from people like yourself. Until now, all my knowledge on keying has been self taught by reading and watching. I guess somewhere along the way, I got the impression that the best workflow when on a greenscreen set is to be able to view your key as a preperation part of the production. Live\Real time preview was the way I read and learned.

Maybe you are right about this. Maybe this is only done on high end sets with high budgets. I guess I thought this was a standard workflow with all productions.

I guess I will have to shoot a few minutes, import it to the computer and check the key. If it’s not perfect, adjust the lighting and do the same thing again.

Maybe making a live key previewer program would be a good idea for a business 🙂

[Rob Jackson]

I don’t have an answer for you, but a question for anyone who might know. What do news stations use to do the live weather reports when they’re standing in front of the green screen as a map? Would that do what Zvi is looking for? Or is that getting ridiculously high end? Our college news station had that and I know their budget was not very significant. Just a thought.

[Zvi Twersky]

Rob, I’m pretty sure they use switchers and other controllers and hardware for that. Yes, that would be going high end. Am I right?

[John Sharaf]

Broadcast News (and Weather) that uses keys and virtual sets most all use switchers with built in keyers. They use multiple layers of these to put in news crawls, chyrons and other graphics on top of the foreground talent and background maps. I’m sure there are other software solutions, but the modern switchers provide a tactile user interface that has great familiarity in broadcast control rooms.

JS

[Mark Suszko]

Zvi, don’t get frustrated, I’ve been doing this stuff since about 1977 and no way do I know even half of what I want or feel I need to know; I’m still learning, every day. That’s why I come here.

At our studio, we approach chromakeys in 2 ways; we have a Grass valley 200 switcher that will enable a live key against a still or other motion video that’s playing off a deck. If you have all the elements ready on shoot day, it is nice to be able to pre-compose the thing live and record it and take that on to post production, a big time saver.

until…

…Until the clients want a change, and now you’re locked into what was pre-composited live on the set. Then you have to call the talent back and re-shoot. Hopefully, there is time and money for that. If you just shoot on the green and do the key later in post, you have MUCH more control and the ability to un-do everything as well as re-purpose clips. So I kind of prefer to do it all in post, but even then, I will often check the quality of the key using the live switcher, to key against a generated color bars chart, some test still, a color frame of white, or something else, knowing that if the old, standard-def composite live switcher can pull a good key, I should be able to as well or better in post.

Now the question arises; for what you are doing, (which I guess is like training lectures or sales talks, you weren’t very specific) do you *need* the switcher with built-in keyer on the set, or is it just handy to have as a time saver?

You can find some switchers for as low as a grand, but HD switchers that use SDI inputs are going to run a lot more money, I’ll say twenty grand, just to pull a number out of my, um, hat. Could be less, but likely more. Especially one that can switch MPEG. MPEG 4 is a delivery codec and is awesome for that, not so great for editing, and tricky for shooting. Only you and your boss can tell if that investment in the switcher is going to be worth it.

If you were going to do webcasting live, then you’d probably need it. If everything is going to be finished and polished in post, then maybe not, and all you’d need on the set is a good tool for evaluating the quality of the lighting on the green; a set of wave form and vector scopes will do this, hardware-based (expensive) or virtual, like Adobe On Location, or the scopes in a copy of Final Cut or Premiere with a suitable video card to take a live input. Being able to take a grab from Adobe On Location (or another similar app) and testing it in Photoshop should take all of 2 minutes to confirm that your set is lit in good shape. When i am shooting green out on someone else’s location, I don’t often have a scope at all, I use the zebra bars display to “eyeball” it, and thanks to aving done this a time or two, I am not too disappointed when I egt back to the shop. But those are very small and tightly shot things, not something very complicated.

That’s what I was trying to explain. There’s always more than one way to get there, but you want the way that makes the most sense for your needs. And the budget and schedule. FAST, GOOD, INEXPENSIVE; you can pick any 2 but ONLY 2.