View Full Version : HV20 working out well for greenscreen!
Ben Syverson November 4th, 2007, 11:20 PM Hey all,
I'm working on a new version of dvmatte pro, and so far, the HV20 is really faring well! Check it out here... (http://vimeo.com/371131)
A couple notes:
I'm currently evaluating different image controls on the HV20 to maximize the results for greenscreen. So far I've been using a "Custom" image setting, but I'm going to do some tests with the "Low Sharpening" mode soon. The custom settings I'm using right now are Sharpening -1, Contrast -1, Color -1, Brightness +1... I'm also shooting in 24p, and using the Cine setting. Those Custom settings combined with the Cine look gets you the lowest-contrast image out of this camera, which is invaluable when doing further processing... Also, the miniSD trick really helps when you're doing keying, because you want to be at 0db gain.
I'm frankly pretty blown away by the image quality on this $900 palmcorder... The times, they are a-changin'...
- ben
Ben Syverson November 5th, 2007, 12:31 AM Someone asked about my greenscreen setup -- I shot this against two pieces of fluorescent-green posterboard taped together. For headshots, this stuff is actually pretty nice. It's a very bright green, which is just what you want. And you can't beat the price, at $1/sheet. :)
Dale Backus November 5th, 2007, 12:49 AM Good deal - i've had very good results as well capturing HDMI.
Are you going HDV or HDMI?
Ben Syverson November 5th, 2007, 02:23 AM HDV -- I don't have a way to capture HDMI yet. I'd be curious to compare the two. Although I don't think the HDV compression is the limiting factor anymore...
Adam Perry November 5th, 2007, 11:43 AM that looks really good! ill have to check out your keyer sometime.
Ben Syverson November 5th, 2007, 12:57 PM Thanks Adam! This new version will be a doozy.
Dale Backus November 5th, 2007, 02:24 PM I'm impressed the HDV did so well for you!
However, capturing with CINEFORM is immensely superior - if you ever get the opportunity i'd definitely give it a try!
John Hotze November 5th, 2007, 02:40 PM Hey all,
I'm working on a new version of dvmatte pro, and so far, the HV20 is really faring well! Check it out here... (http://vimeo.com/371131)
A couple notes:
I'm currently evaluating different image controls on the HV20 to maximize the results for greenscreen. So far I've been using a "Custom" image setting, but I'm going to do some tests with the "Low Sharpening" mode soon. The custom settings I'm using right now are Sharpening -1, Contrast -1, Color -1, Brightness +1... I'm also shooting in 24p, and using the Cine setting. Those Custom settings combined with the Cine look gets you the lowest-contrast image out of this camera, which is invaluable when doing further processing... Also, the miniSD trick really helps when you're doing keying, because you want to be at 0db gain.
I'm frankly pretty blown away by the image quality on this $900 palmcorder... The times, they are a-changin'...
- ben
I'm not familiar with how a keyer works but I was thinking that you could only use them with pro cameras. Where can I get some information on the dvmatte pro?
Ben Syverson November 5th, 2007, 03:44 PM I'm not familiar with how a keyer works but I was thinking that you could only use them with pro cameras. Where can I get some information on the dvmatte pro?
Yeah, a lot of people assume they can't do greenscreen unless they have a high-end camera, but you can get some great results with small cameras these days!
dvGarage (http://www.dvgarage.com) distributes my stuff, but I'm about to release a new version -- check the site in a couple weeks!
Paul Tauger November 5th, 2007, 04:02 PM Yeah, a lot of people assume they can't do greenscreen unless they have a high-end camera, but you can get some great results with small cameras these days!
dvGarage (http://www.dvgarage.com) distributes my stuff, but I'm about to release a new version -- check the site in a couple weeks!I didn't realize you wrote this stuff. I just looked at the dvmatte products on the dvgarage website. Very impressive!
Stephen Chan November 6th, 2007, 04:27 AM Very impressive for an inexpensive camera and impressive software too.
John Wyatt November 6th, 2007, 05:05 AM Ben,
I've been considering experimenting with no budget greenscreen work for a long time and would like to go into this. Especially because, with no budget, you need all the help you can get to make your film look more than it is -- and greenscreen is a marvelous way to do that (with no boundaries!). When I have time I'll sort out my plans and get your software.
sorry to go off topic, but is your LinBayer software still available? I know several years ago you were experimenting with a Sumix camera head -- there's a new one out with a credible sensor (look in the Alternative Imaging section). Your program may be of interest to the people on that thread...
Regards,
John.
Adam Perry November 6th, 2007, 09:28 AM cool, ill be checking back soon. need to try that posterboard idea too, looks like it gives good results.
Ben Syverson November 6th, 2007, 12:20 PM Especially because, with no budget, you need all the help you can get to make your film look more than it is -- and greenscreen is a marvelous way to do that (with no boundaries!).
Definitely -- greenscreen has become routine for even non-effects movies in Hollywood, and I'd like to see indies have the same flexibility!
sorry to go off topic, but is your LinBayer software still available?
Geez, I don't even know where LinBayer is in my archives... It wouldn't be hard to replicate that work. It was basically a logic-based debayer algorithm on top of a pretty basic two-pass 1D interpolation (spline?). The logic-based bit was good for pixel-level detail, but it freaked out when it encountered moire, noise, or fine detail past nyquist.
These days, I'd probably strip out the logic layer and just work on getting the best possible interpolation.
Incidentally, it would be very easy to write a GPU-accelerated bilinear debayer plugin for previewing raw footage -- it would run faster than realtime on most systems...
John Wyatt November 7th, 2007, 04:35 AM Ben is the new version of dvmatte pro Mac-only?
Ben Syverson November 7th, 2007, 12:50 PM Yeah, I'm focusing my development efforts on Final Cut Pro right now. FCP has an amazing realtime processing path, and it's very accessible to developers...
Alex Leith November 7th, 2007, 07:03 PM As a long-time DV Matte Pro user, I am very excited about what I'm seeing there for the new version...
I'm also considering an HV20 as a second camera... so it's nice to know that it will capture chroma-keyable footage okay.
Ben Syverson November 7th, 2007, 10:12 PM This new version is a whole new world... and the HV20 is an awesome machine!
Todd Clark November 8th, 2007, 08:00 AM Are you going to have a new version for After Effects or Premiere Pro?
Ben Syverson November 8th, 2007, 02:47 PM Maybe at some point, but not right away... I'm moving away from traditional CPU-based effects. Once you see a MacBook Pro playing back a 720p dvmatte pro composite in realtime -- and you're able to tweak dvmatte parameters as it's playing -- After Effects begins to look extremely unappealing.
Yang Wen November 9th, 2007, 02:45 PM Your hair is transparent.
Maybe you have thinning hair too like me.. ;)
Ben Syverson November 9th, 2007, 03:01 PM Yeah, I might have gone a little too light on the hair... there's a slider that lets you adjust how dark those fine details are.
Joseph H. Moore November 10th, 2007, 08:23 PM Very nice. I'm going to have to give the new version a hard look. Will you post back here when it is available?
Your sample was scaled down to SD. Do you really think that at HD dimensions the added color resolution of straight HDMI capture (4:2:2 vs HDV's 4:2:0) won't make a significant difference in edge quality?
Ben Syverson November 10th, 2007, 10:46 PM Joseph,
The sample I posted is in HD resolution -- to see the full 720p, make sure you have the "HD on" button toggled in the Vimeo player. You probably want to hit "full screen" too...
You'll probably see a small advantage from capturing to HDMI, but for most subjects, the pain of shooting tethered to a desktop machine with an HDMI board won't be worth it. I know I'd rather shoot to tape or to a laptop... :)
Joseph H. Moore November 11th, 2007, 08:04 AM Found the Quicktime at the bottom of the screen.
Very nice raw results. With the right lighting and the appropriate bkg plate you defintely could make tricky composites that sell on screen, even with HDV.
Please do let us know when the new version ships. Do you have a list of the improvements anywhere?
Ben Syverson November 11th, 2007, 02:12 PM Not yet, but the improvements are basically:
- Vastly improved fine detail response. It's now possible to preserve even the finest details. Tiny wisps of blonde hair can be reproduced.
- Dynamic spill suppression. Normal spill suppression corrects the green of the greenscreen to one specific color -- usually a brownish gray. The new dvmatte considers the background when de-spilling, changing the spill parameters on a per-pixel level.
- When compared with older versions of dvmatte, the new version is somewhere between 10 to 100 times faster, thanks to GPU acceleration. You can key 720p footage in realtime on a laptop!
Joseph H. Moore November 11th, 2007, 03:07 PM That's some list!
Ben Syverson November 11th, 2007, 07:31 PM :)
In the past, the software was really the limiting factor. You could have pretty good footage, but not be able to make an acceptable composite. But with this new version, I think we're finally brushing up against the limits of the greenscreen process itself...
The new fidelity of the process can be a double-edged sword; reproducing all that subtle detail means we're also reproducing any tiny mistakes or problems. The new dvmatte will render even the finest wisps of hair, but if you're not careful, it can also faithfully reproduce vignetting, uneven lighting, camera noise, and tiny screen imperfections. If you use a cloth greenscreen like I sometimes do (the ones from Composite Components are the best on the planet), you have to be careful when shooting HD, because dvmatte will even reproduce the fine weave of the fabric!
Of course, I have tools in the dvmatte toolbox to deal with that, including a screen correction plug-in, and a screen cleaner that scrubs away detail from empty areas of the screen. But the less work those plugins have to do, the better.
It'll be interesting to see how people take to this new version -- it shifts a lot of weight from my shoulders to the person lighting and shooting...
Stefan Szabo November 13th, 2007, 08:40 AM Hey Ben, the new version looks awesome!!! Do you have any idea on when it will be available for purchase, and what it will be called? I'm anxious to get my hands on it.... Thanks!
Stefan szabo
Ben Syverson November 14th, 2007, 02:22 AM Thanks Stefan!
From what I gather, we're set to release sometime late this month or early in December. It'll still be called "dvmatte pro," and will still be distributed through dvgarage.com
Lawrence Bansbach November 15th, 2007, 08:57 AM What bit depths will the new version of dvMatte Pro support -- full 32-bit floating point? What resolutions? And will there be a Windows version at some point?
Ben Syverson November 15th, 2007, 01:25 PM Lawrence,
The plugin will run at 32bit floating point, but there is no benefit to doing so. Internally, the plugin operates at 32 or 16 bit floating point, depending on the graphics card present. So even working with 8 bit footage, you get the precision of floating point.
The resolution is limited by what the graphics card can handle. Most cards are 2k at this point, but some new cards have 4k support.
Joseph H. Moore November 15th, 2007, 07:19 PM It's sounds like the newly announced FCE 4 supports the same plug-in architecture.
Ben,
Do you think it's likely that the new dvmatte will function in the new Express?
Ben Syverson November 16th, 2007, 01:23 PM Joseph,
I haven't done any testing with it, but FCE does support FxPlug, which means dvmatte will probably run great!
Kent Golden November 23rd, 2007, 01:18 PM Hi Ben,
I do a lot of chroma keying and just purchased an HV20. Your dvmatte sample looks great!
Can you please tell me if you recommend using the 24p mode or the normal interlaced mode for chroma keying with the HV20?
If you recommend 24p, can you also please let me know which process you use for encoding the video with the HV20 (i.e. do you get true 24p with the reverse telecine)? Are you using Apple's method (in link below)?
http://docs.info.apple.com/article.html?artnum=306389
I have an important project coming up, and I want to be sure everything will work properly.
Thanks!
- Kent
Ben Syverson November 23rd, 2007, 01:55 PM Hi Kent,
Cool! You won't be disappointed. The choice of 24p or 30i will really depend on the rest of your project, since you presumably want the greenscreen stuff to fit in with your other footage...
That said, progressive footage may have the edge, because interlacing really stresses the MPEG codec used in HDV. Also, 24p is more sensitive to light, so the camera won't kick on the gain as quickly.
I do use that Apple technique to convert the footage to true 24p. It works great!
Kent Golden November 23rd, 2007, 02:24 PM Hi Ben,
Thanks for the info. I am actually using the chroma footage in a Flash program, so progressive seems best.
Thanks again!
- Kent
Les Caudle November 23rd, 2007, 08:14 PM Ben - I purchased an Intensity card to use with Final Cut Studio 2 and the HV20 for green screens.
1. When I capture at 1920 x 1080 60i 'live' from the HDMI (to ProRes 422 HQ), exactly what am I getting? I get very different feedback depending on who I ask.
Is it 60 fields, each recorded at 60 distinct intervals per second (no field matches the time of any other)?
Or, is it 60 fields, with 2 field recorded at the exact same time, the frame broken up into even and odd fields so that it can be packaged in 60i?
2. If I capture 24p HDV, encapsulated in 60i, what am I getting? Are there 48 fields (odd and even) captured at exactly the same instant, but packaged into a 60i stream with the pulldown frames added?
In other words. Is it progressive for HDMI capture? Is it progressive for HDV 24p capture? But, all packaged within 60i?
3. Are there any settings on the HV20 that will affect the output when capturing thru HDMI? I'm really hoping that with the better color space - and no MPEG compression, I can get better output.
4. Any word yet on when your new version of dvMatte Pro will be out?
BTW - it would be nice to have a 'versions' page on the dvgarage.com site. I have no idea what version is currently shipping, the bugs fixed in previous versions, etc.
Joseph H. Moore November 23rd, 2007, 08:52 PM 1. When capturing 60i, each field is a unique moment in time, each field is different. This is easy to see when you step through your deinterlaced footage.
2. When capturing 24P, each combination of fields is a discrete moment. The sensor is truly progressive.
3. Whether recording to HDV or going out the HDMI port, the 24P is encoded into a 60i stream.
4. Most, if not all, of the HV20's image settings affect the HDMI output. If you think about the image chain, the HDMI output sits immediately before the HDV compression.
5. You're gonna want to keep all of the image settings at 0 or -1. Especially SHARPNESS if you're keying.
Les Caudle November 23rd, 2007, 09:19 PM Joseph - why in the world would they use a progressive sensor and muck it up by taking 60 distinct fields? They could have packaged this as 30p in 60i, couldn't they?
You seem to be saying that 24p is possible out of the HDMI?
Is there a way to get 24p, or any true progressive stream - out of the HDMI with a 'live' capture? Or, am I stuck with 60 discreet odd/even moments in time that won't exactly ever fit together properly?
BTW - if you happen to be a FCP user, any tips on the best way to de-interlace the 60i HDMI, if what I'm stuck with are truly 60 distinct moments in time, how can you de-interlace something where the parts are not meant to fit together?
Ben Syverson November 23rd, 2007, 11:18 PM Les,
Shooting in 24p and outputting to HDMI, you're getting true 24p, spread out over 60i. What's happening is that telecine-style "pulldown" is being applied. This means some frames will be spread out over fields. I don't think there's a HDMI (or HDV) standard for 1080p @ 24fps, so they're forced to use this hack to remain compatible. Unfortunately, 24p was not really on the radar a million years ago when all these standards were agreed upon.
To remove the pulldown, you should be able to use Compressor. I'm not sure whether Compressor will be able to determine the cadence automatically or not -- if it can, it may be as simple as using the Deinterlace: Reverse Telecine option. That's how it works with 24p HDV. If that's not an option, you may have to involve Cinema Tools (?).
I'll see if I can find out for sure.
The timetable for the dvmatte release has been pushed back slightly -- unfortunately, it's sort of out of my control. Right now it looks like we may release at Macworld (January)...
Ben Syverson November 23rd, 2007, 11:22 PM BTW, on the subject of image settings... I learned the hard way that you don't want Color +1 when doing greenscreen. It looks good on-set, but it's really pushing the green in an unnatural direction. Color -1 works much better.
And definitely remember Sharpness -1, and Contrast -1. Those are key.
Joseph H. Moore November 23rd, 2007, 11:30 PM Les,
Apple has a technote on a good workflow for removing the pulldown, or "inverse telecine." You will end-up with true 24P. 24, full resolution, discrete moments in time.
- As already stated, both the HDV and HDMI standards necessitate encoding into a 60i stream. Except for a few oddball cameras and situations, 30P isn't really used anywhere. 1080/60i or 720/60P are both HDV standards.
- It's actually nice to have the 60i option, even for "film" work, because you can use it for some pretty nice slow-mo effects. (you give up some spacial resolution due to the interlacing, but the temporal resolution more than makes-up for it, IMHO.)
Les Caudle November 24th, 2007, 09:30 AM Ben - My real concern is with the uncompressed HDMI output while recording 'live'.
1. Is the 60i from HDMI 'live' composed of 60 distinct fields from 60 different points in time (not progressive at all). Is what I'm after really 30p - that when you say 60i this implies the frames are all from distinct points in time?
2. Does this differ from the HDV 24p packaged in 60i? With 24p, are there matching odd/even fields making up one frame from one discreet point in time (with dropdown added) - truly progressive - or is this 'simulated' 24p, where the odd/even frames are not from the same moment in time?
3. For dvMatte Pro, will there be a beta release? Will this be a version upgrade where if I purchased now, I'd have to pay more? Will it work ok with the 4-2-2 colorspace from direct HDMI capture?
Thanks!
Joseph H. Moore November 24th, 2007, 09:37 AM 1. Is the 60i from HDMI 'live' composed of 60 distinct fields from 60 different points in time (not progressive at all). Is what I'm after really 30p - that when you say 60i this implies the frames are all from distinct points in time?
Yes and yes. You want 30P, and the HV20 does not have it. Nor does almost any camera.
2. Does this differ from the HDV 24p packaged in 60i? With 24p, are there matching odd/even fields making up one frame from one discreet point in time (with dropdown added) - truly progressive - or is this 'simulated' 24p, where the odd/even frames are not from the same moment in time?
Yes, this is different. You will get 24 full, true, progressive frames if properly decoded. I promise, but you don't need to believe me. Just download some 24P footage from the camera and look at it frame by frame.
Les Caudle November 24th, 2007, 09:46 AM Joseph - if I'm shooting green screen of a subject with a lot of motion. Will I get better results with 24p packaged in 60i:
advantage true progressive, so de-interlace would work perfectly; disadvantage less frames per second, 4-2-0 color space, MPEG compression artifacts
or HDMI uncompressed at 60i
advantage 4-2-2 color space, no MPEG compression, higher frame rate; disadvantage fields cannot truly be de-interlaced properly as they are all different moments in time?
Thanks!
Joseph H. Moore November 24th, 2007, 10:11 AM No, Les, the 24P is "packaged" inside of 60i whether you record to tape with HDV or if you stream out of the HDMI port. (This is called "telecine" and it's a very old, proven technique.)
You can go out of HDMI and get all of the quality benefits for keying. All you do is make sure the recording mode on the camera is 24P and you're good to go. Again, you have to decode the 24P out of the 60i stream, but it is true 24p not a 24F hack.
I hate to confuse you any more at this point, but there is one caveat about the HV20's 24P encoding. The camera does not flag which fields go with which frames, so you have to be careful to use a tool that actually analyzes the image and finds the start of the 2-3 "cadence" that defines the 24P frames.
(Cineform's capture software can actually do the inverse telecine on the fly, but it is a PC only option at this time.)
Les Caudle November 24th, 2007, 12:22 PM Joseph - I understand you to say that I can capture 'live' thru the HDMI in 24p, skipping all the MPEG compression and getting 4-2-2 color space.
Or, are you saying you can capture 24p thru HDMI of previously recorded HDV - in which case there is no advantage to using HDMI over Firewire. That the 24p will be 4-2-0 and MPEG compressed no matter what.
Thanks!
Joseph H. Moore November 24th, 2007, 12:30 PM Sleep easy, the 24P is nestled safe and snug (prior to nasty HDV compression) inside the 60i, 4:2:2 HDMI stream. It looks gorgeous.
Once it is recorded to tape, though, even if you go out the HDMI port, it has been mangled. This only works for "live" capture.
Les Caudle November 24th, 2007, 01:14 PM Joseph - YES! That is great news.
BTW - if you are on Final Cut Pro, what is the best way to de-interlace and reverse telecine the 24p captured using HDMI? My capture format is ProRes 422 HQ.
Should I just follow the Apple tech note starting at step #2?
http://docs.info.apple.com/article.html?artnum=306389
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