A nice workaround for the 4:1:1 colorspace.....

Considering the fact that most of us cannot afford to purchase expensive high end capture cards, we are mostly stuck in graphics hell also known as 4:1:1 colorspace DV. Titles, 3D animation and other graphics get KILLED here. You lose your stars, detail, titles are blurred etc. Well, I figured out a nifty little workaround for this in the macintosh environment.

2 things.

1. It does not help as far as compositing is concerned. One way to get around that is to capture your DV footage through an analog ( composite, s-video) connection. You will lose quality, but be able to pull off a better key. With some color correction and tweaking, you may not notice if it is cut together with FW DV.

2. This method is ONLY good for DVD/WEB/VHS delivery. If you go to miniDV, you are going to get that compression that we are avoiding.

Okay, here we go....

When you finish you animation, render it to the animation codec. It is a GREAT codec. If you prefer a different codec, than go ahead.

Now, you need MpegAppend, which is a free mpeg tool that combines M2V seamlessly together.

You encode your video to Mpeg 2 as you normally would. Then you encode your graphics straight from the animation codec to Mpeg2. Then you use Mpegappend to seamlessly tie them together in DVD Studio Pro. Viola!

Your graphics never went through the DV compression because it was never placed in your DV timeline in your NLE. MpegAppend lets you select the order for which you want your m2v files to play and converts the timecode to drop timecode which can also alleviate some sync issues.

You can get MpegAppend at
MPEGTOOLS
http://homepage.mac.com/DVD_SP_Helper/MPEG%20Append/MPEGAppend.html

 

This sounds great... if I had a mac. Can you try and put this is PC language? Also I am not that technically talk savvy, so could you elaborate on all this?

-Josh

 

It is pretty much the same. The only thing is, you'd have to find a PC program that can seamlessy combine the M2V files.

In you graphics program ( AE, MAX, PS) you would render out to a lossless codec ( animation, PNG, etc). Edit all of your footage minus the cg and graphics in your NLE ( premiere etc). Then export everything to Mpeg2 seperately and use the other application ( if one for the pc exists) to join the m2v chunks.

 

I hope I don't sound stupod... but I am... can you put all that in laymans terms.

-josh

 

One thing I've found, in general, is that Difference Keying works WAY better than Chroma or Color keying with miniDV sources.
With Difference Keying, you can work VERY effectively with a direct miniDV source.

You still use a blue/green screen, but the matte is much more precise, since it uses color AND brightness to calculate. It's best to capture an empty background plate before shooting each angle for this, but I've been having a lot of success even by copy/paste/cloning background plates by combining frames (Didn't know about difference keying when I was shooting my action. Grrr.)

I have some examples at home. Will try to post them later tonight.

Have fun!

 

Oh yeah, the color difference key rocks for crappy BS/GS on dv.

 

**wonders aloud... what in the heck are they talking about.**

(Josh wonders because he doesn't know all this fancy talk.)

 

I'd like to try this some time myself and see what the results are.

Secondly, I have to ask because I'm relatively new to the FanFilm forum, but I've been around the JC and formerly Jedinet for "eons" (since 1997 on and off)... and I've worked with video on and off for years...

What is everyone's opinion here as far as the lighting setups for most chroma key shots? Do people follow the "rules" of chroma key? By this I mean is everyone lighting the blue/green screen completely and also lighting their subject with front fill, key and back fill lighting? Robust lighting is the first issue in tackling the limitations of the 4:1:1 colorspace when keying. Most of the setups I've seen stills of on fan film pages are competely inadequate for proper keying.

Do most people use actual true chroma-blue or chroma-green screens or just find something that looks green or blue from their local JoAnn Fabrics store or something? Using true chroma green or blue screens makes chroma keying pretty much a one-shot job.

Setting aside the inherent limitations of the DV 4:1:1 format, blue screen or green screen key in Premiere, with true chroma backdrops and proper lighting conditions, works pretty well just with the preset defaults, as opposed to using the more dynamic "chroma key" that can be set to almost any color or color range. This is because true chroma blue or chroma green mattes, boards and fabric are both non-reflective and of an absolute G or B chroma value such that when lit properly, there is ZERO variance and the entire backdrop should be keyed out if the key is set to absolute chroma blue or chroma green. Using proper key backdrops and lighting setups alone will decrease your keying problems a hundred fold.

Of course, not relying upon effects that don't work well with the resources you have will eliminate these problems entirely. I say if you can't make it look good, find other creative ways to tell your story.

Lastly, is everyone aware that programs such as Premiere actually use fast-decompression in the project monitors such that the preview, even when rendered, is slightly inferior to the final export-to-movie or export-to-tape output?

Now I'm kind of wondering if I should create a test disc somewhere along the lines of the THX optimizer, but designed with files to calibrate both your DVD player, NTSC monitor, computer CRT and audio reference monitors... to help us all calibrate our systems to a uniform production standard optimized to make the best of the DV format.

EDIT: But yeah, as mentioned above, you will have compression artifacts in keying when exporting BACK to MiniDV tape... best to not export keys back to MiniDV.

EDIT 2: In regards to the original idea... instead of rendering out your key back directly to DV, another thing you could do is render the entire project to another codec... or, if you have the space, to a completely zero-compression codec (provided you have a fast enough hard drive)... either way, render out the entire project to a codec other than DV/DVCPro... then create a new project and bring in your complete rendered video. Now instead of having key layers that will render out to DV... you have one seamless movie that this project doesn't "realize" has been keyed... now render THIS project back out to DV/DVCPro codec.

My thinking is this:

1. Every project you do in DV doesn't produce artifacts when not keying.

2. Keying and rendering to DV does produce
artifacts.

3. By rendering your entire project to a codec other than DV, you're creating a master file that is now a fully-rendered composite... but the new project doesn't know that you've previously keyed this... because the layers are... that's right... GONE! It's one seamless image being rendered to a DV codec.

I'm not sure if this will work, but it seems logical to me... I'm going to test it this weekend if I get a chance.

 

The answer is going to depend on who you ask.
I know that some productions have used genuine chroma products in pro studios (Duality, Broken Allegience and Daft's upcoming Storm Ahead come to mind)

For many of us though, using various "home" products are the best we can afford. You can see my own bluescreen in this tutorial. Not even close to state-of-the art.

I did light the set as best I could. A bank of shop lights were aimed at the backdrop, while the action was lit with a separated set of flood lights. I also kept and extra flood handy on a portable stand, to fill in shadows as needed.

DaftMaul might have some useful insites, as he's used a GL1 with both home made and genuine chroma setups.

"I say if you can't make it look good, find other creative ways to tell your story. "
VERY good advise. Poorly executed effects are a major distraction!
Seeing good story with fewer (to no) effects is much more fun than watching a series of almost-cool effects.

Have fun.

 

If your NLE is "DV Only" get a new NLE.

For CGI render to something other than DV, for example HuffYUV a free lossless compression codec. Most NLE's and compositor software support any codec on your system. You are not locked to DV.

Make mpg's and all that is just a silly workaround.

Also, a tip for better keying: Blur your footage before the key slightly. Then create the key and set your keyer to output the MATTE ONLY , *NOT* the composit. Then use THAT layer as the track matte of an UNBLURRED version of the footage. Doing this allows you to easily blur the key too, if you want to. Both works in different situations - experiment.

Stuff like Combustion has "pre key" and "post key blur" built in.

/Z

 

EDIT: There's a lighting equipment supplier in Minneapolis where I bought my chroma screens... they have 40x30 inch card sections for $6 each. Also they have foam-backed chroma fabric for about $5 per foot (one yard wide). Sections can be attached with chroma tape. Not as expensive as I was expecting.

I thought of another approach, but it's going to require the following... If you don't have the following, then do not attempt... it'll be more time consuming than its worth, otherwise:

1. True chroma blue/green screens.

2. Adequate key, fill and back lighting for subject.

3. Adequate fill lighting to evenly and completely illuminate chroma key screen.

4. Adobe Photoshop, Premiere. Photoshop 7 and Premiere 6.5 would make this pretty damned easy.

If you have all this, you should be able to do this easily, but it may take quite a bit of processor time, depending on file size:

1. Capture your chroma screen subject video on DV as usual.

2. Insert your backdrop image(s), cropped to the appropriate 720x534, 72dpi, RGB gamut, into V1A and/or V1B on the timeline.

3. Drop your video to V2 on the timeline.

4. If your chroma screen is not large enough to cover the entire frame of your video, if portions are uncovered, create a garbage matte with an absolute chroma value matching your screen (blue=255 or green=255, whichever you're using) exactly, to eliminate non-green or non-blue areas, or any mics, etc. you want to remove from frame, and export only the V2 w/just the garbage matte rendered to a filmstrip file.... separately... with all other layers invisible so they do not composite.

5. Export the exact same number of frames of your background plate(s) in V1A/B as the number of frames in your foreground key plate to a filmstrip file... separately... with all other layers invisible so they do not composite.

6. Open the background plate filmstrip in Photoshop. Rename the background layer "Background Plate".

5. Open the foreground filmstrip and copy the entire filmstrip into a new layer, and rename the layer "Key".

6. Create an effects layer, attached ONLY to the key layer, to eliminate the color value associated with your chroma screen and matching garbage matte.

7. Before flattening the image, review the key layer frame by frame and airbrush out any undesired artifacts.

8. Once the final 2-layer composite passes inspection, flatten the image.

9. Export/save the fully-composited filmstrip.

10. In Premiere, import the composited filmstrip and put it back in your timeline in place of the separate layers.

Now what you have is a pre-composited video clip that, for all intents and purposes, Premiere doesn't have to recompress as a composite, but as any other video clip in the timeline.

Following the conditions I set forth earlier, with a lot of patience, and incredible attention to detail, this technique should produce a final shot as seamless as any done in Ultimatte or Combustion... a lot more work, but it won't cost you thousands of dollars in software/hardware (Even the best MiniDV cam is constrained to 4:1:1. I think you have to go to DVCPro, DVCAM, Digibeta or HD to get 4:2:2, if I'm not mistaken... but yer talkin' $20,000-$50,000.)

For added insanity and quality... you could use Premiere's effects layer masks to also create special lighting adjustments across the board to make the multiple layers' lighting match one another more closely for a smoother comp.

 

Zap, do you realize that you ALWAYS come across in your posts as arrogant? "Get a new NLE??" It is not the NLE that is the problem. Sure you can work with any other codec, but come delivery time, where are you going? DV!! I have FCP and when I mix animation and DV without the help of an uncompressed capture card ( which I DO have) MpegAppend is a good way to avoid DV compression when mixing DV and graphics and delivering to DVD.

Another note about this process. Your best bet is to work in a linear format when you are mixing to DVD. You can work NL offline, but when you are going to create your m2v's using mpegappend, you need to do each sequence ( not clip) in order.

 

Zap, do you realize that you ALWAYS come across in your posts as arrogant? "Get a new NLE??"

No, I didn't. I intend to come of as humorously smug with a nudge-wink angle.

It is not the NLE that is the problem. Sure you can work with any other codec, but come delivery time, where are you going? DV!!

Just because your delivery format is lossy/crap and your source aqquisition format is lossy/crap absolutely does NOT mean you have to use lossy crap as an intermediate storage! QUITE the contrary actually! Thats when using lossless/good intermediate storage is MORE IMPORTANT THAN EVER!

I have FCP and when I mix animation and DV without the help of an uncompressed capture card ( which I DO have) MpegAppend is a good way to avoid DV compression when mixing DV and graphics and delivering to DVD.

I would personally never recommend doing any compositing in the MPEG realm. MPEG is a delivery format and is much worse lossy than DV (okay, depending on bitrate, but still).

/Z

 

I agree with the point about not compositing in MPEG... come to think of it.

That would make my last post a better option than the second to last... by a longshot.

 

We are NOT on the same wavelength here at all. I never mentioned compositing in Mpeg format. As a matter of fact, my original post states that Mpegappend is good for graphics and will NOT help out in compositing.

Let me demonstrate my workflow for you as I have probably explained myself poorly.

Import DV into FCP via fire wire.

Edit sequences with preferred codec ( DV for DV, animation for animation, etc) What I was suggesting is that you stick to the rendered codec in your sequences. Instead of editing everything in your dv timeline and then encoding it to mpeg2, you encode to mpeg2 direct without mixing codecs and rendering. Then you go in a linear order and patch the Mpeg2 files together.

 

OK. Got that example ready.
This one showcases the results fairly well, thanks to the hair detail.
I'm not sure what Primatte, Compositing Toolkit or even out of the box AE would have done with this, but all I've got is my NLE, Media Studio Pro. Keying this as color or chroma was hopeless around the edges, especially around the hair since it's even translucent in a couple spots.
Difference keying worked like a charm!

Original miniDV shot
(If you look closely, you can see the miniDV color compression really shows along the left edge.)

Finished Difference Keyed Composite

Another advantage of the this is that there is no re-rendering of the original video before getting to the final, so, other than deinterlacing, there is no blurring or image quality loss in the composited render. There were a few renders involved to generate the mask, but the image itself went directly from the original miniDV to the uncompressed final shot for used for scene editing.
If anyone is interested, I might try to get around to writing a new tutorial on this. The technique has been refined a bit since my last one.

Have fun!

 

Nice key! I don't have much experience in keying, so I will definitely keep the difference matte in mind.

 

Going back to the original topic for a moment, I don't really see the point. You're describing a workaround to a "problem" that no one I've ever worked with has ever had. Capture DV footage.. Render 3D animation or 2D titles. Edit them and save out. I can't think of a single person off-hand who renders any 2D or 3D effect into DV format. Yes, rendering 3D into DV causes horrible compression, so we don't do it. Plain and simple. There's your workaround.

As far as the keying and compression of live footage goes, my workaround involves shooting and capturing in 4:4:4 colorspace, but that's just me.

 

As far as the keying and compression of live footage goes, my workaround involves shooting and capturing in 4:4:4 colorspace, but that's just me.

What camera do you have that shoots 4:4:4 color space?

I like the difference matte and it works well if your resources are limited, but I do have about 2000 watts of fill lighting and true chroma blue and green screens which allow me to use the blue/green screen keys without much tweaking.

I am trying the track matte technique suggested earlier, and currently running tests to compare it against the standard chroma green key.

 

Right now I'm planning to use something akin to the Panasonic AJHDC20A HD camera. Word has it they're coming out with a 24p version soon, that's what I'll be shooting with.

 

Well crap! HD is TOOOOOOOTALLY different! I can't think of a single soul amongst us who wouldn't give their genitalia to shoot in HD! But we're talking about DV, so...........up your nose with a rubber senator!

 

You are missing my point here. If you want to mix graphics and DV together on a DVD and have the scenes cut together seamlessly, you can't unless you render them all together in a sequence in your NLE. With Mpegappend, you can chunk m2v files together. This way, you can go directly to Mpeg2 with your animations. When you author your dvd, you link the moeg2 animations with the mpeg2 dv footage. While it is compressed more the DV, mpeg2 is A LOT more forgiving on graphics.

 

Right now I'm planning to use something akin to the Panasonic AJHDC20A HD camera. Word has it they're coming out with a 24p version soon, that's what I'll be shooting with.

Is that a D9 cam?

Hey, while you're at it... since you have so much money falling out of your pockets... spare a brother $80,000 so I can buy a Sony HDW-F900 to shoot birthday videos. Oh, wait, better make that $200,000... I'm going to need an Avid Symphony workstation, too, to edit all fifteen minutes of the footage.

 

The word of the day is "rental".

 

rental smental.... the real word is LOTTO