hdv to film_ a real-world test

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HDV to Film: A Real-World Test

Making decisions and making discoveries on a tight-budgetfeature.

By John Jackman

In the world of professional video production, the HDV format has gone from

novelty to viability in record time. The rapid changes began over a year ago

when Sony introduced the HVR-FX1, and DVContributing Editor Adam Wilt

pronounced its compressed, MPEG-2 picture to be "better than it has any right

to be." The release of the Sony HVR-Z1U upped the professional-quality ante,

and HDV cameras from Canon, JVC, and Panasonic have streamed into the

market. With slick editing solutions available from all of the major players-

Apple, Avid, Canopus, CineForm, Lumiere HD, and others-the HDV format has

arrived in a big way.

Despite the sales success and broad acceptance of HDV, there is still an

information gap in terms of how well it really performs. Although a lot of HDV

units have been sold, a large number ofDVreaders are still on the fence about

whether to buy into the format or not.

So I decided to put the latest HDV techniques and technology to the test. I

produced a low-budget short from beginning to end in HDV, with the intent of

creating the best possible product in standard definition for DVD distribution,

HD for digital broadcast, and, because the promise of low-budget filmmaking is

driving the intense interest in HDV, I decided to take the piece all the way to a

35 mm film blowup.

The end result is here: An overview of the decisions and discoveries I made

while producing a real-world project in HDV, along with the reactions of some

seasoned DPs to the final film result. I found out a lot during the process-morethan can fit in the pages of the magazine. More details about the project are

available online at DV.com.

Early decisions: Camera, frame rate, and gamma

Armed with the script forWindsor Knot(a historical period drama about the

abdication of England's King Edward VIII that I've been wanting to shoot for

some time), I set out to choose a camera. At the time I was shooting (May

2005), I felt that there was only one viable camera for the project-the Sony

HVR-Z1U (Reviews, May '05 DV). The Z1 has several appealing features, the

most important of which are the abilities to use pro audio connections and

shoot in 1080i-50. Even though creating a 24 fps version for the film blowup

was critical, I found that creating true 24p was easier and more effective in my

tests starting with 50i than with 60i (more about this reasoning can be found

online at DV.com).

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I didn't consider Sony's CineFrame mode, which, though it creates a 24 fps

video file, has unaccept-able motion artifacts and image degradation (for more

about CineFrame, see Adam Wilt's analysis at www.adamwilt.com/

HDV/cineframe.html).

I experimented with the Z1U's CineGamma settings in an effort to achieve a

film-style gamma curve. The Z1U has two CineGamma settings, with

CineGamma 2 being more pronounced. I liked the look of CineGamma 2 and

decided to use that mode in shooting. On inexpensive cameras, these film-likegamma settings are accomplished not with the true S-curve that I would apply

in post, but rather by tilting the straight gamma curve to a more extreme

position Although this accomplishes almost the same thing as the gentle

S-curve, it's not quite the same. It doesn't supply the more gentle roll-off of

highlights and tends to crush dark grays to black sooner.

Click here to see a larger image

Video has a straight gamma curve. Film stocks often have a gamma curve

shaped like a shallow S. (right) Inexpensive cameras with "cine" gamma

adjustments usually simulate this by tipping the straight video gamma.

After testing color tweaks in the camera menus, I left most of the settings on

factory defaults. I turned the sharpness control down considerably, though not

to its lowest setting, which is a tweak I recommend for nearly all cameras if you

want a film-like finish. Reducing the artificial sharpening (technically known as

aperture correction) tones down harsh edges and avoids compression artifacts.

On location: Decisions and discoveries

I was dealing with a microbudget for this project (well under $3,000 for all

expenses and salaries), so I scheduled a single day of shooting on location.

The day came, we showed up with a truckload of equipment and people, and

Windsor Knotwas in production.

The decision to shoot in 50i necessitated a PAL-compatible monitoring solution.

I brought the JVC BYH13Y production monitor from my edit suite.

We monitored composition, exposure, and color on SD via the down-converted

Y/C output of the camera. But we discovered that neither an SD monitor nor the

camera's viewfinder, nor its LCD screen were up to the job of representing

HDV's details-we ended up with slightly soft focus no matter what we used. To

deal with this issue, Sony provides a zoom function on the viewfinder, as well

as a peaking function, which flags high frequencies (such as in-focus sharp

edges) with an accent color (red, yellow, or white). This works well to visuallycue the camera operator when focus is right on. Unfortunately, peaking can't be

used at the same time as zebra display, so the cameraman had to keep

switching between the modes.

The HVR-Z1U also has a basic zebra display that defaults to 100 IRE. We set

the zebra at 90 IRE to avoid the "video look" of overexposure and clipped

whites. I think clipping in HDV is really nasty, even worse than in DV. So an

essential rule for shooting in HDV is don't overexpose!It's much better to be a

stop under rather than a stop over while shooting. If necessary, you can stretch

the contrast back out in post.

Postproduction: Quality control

If I was going to edit on a Mac with Final Cut Pro, my logical choice would have

been Lumiere HD, a plug-in that provides machine control and on-the-fly

transcoding to the editing codec of your choice. But my shop is PC based, so


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the strongest contender was CineForm's Aspect HD plug-in (Reviews, July '05

DV), which works in Adobe Premiere Pro 1.5.1.


Editing was done in Premiere Pro 1.5.1 in 1080-50i using CineForm Aspect

HD Codec.

Editing native in HDV with no quality loss is now touted by some NLE vendors,

but it was not an option forWindsor Knot. Because HDV's MPEG-2

compression retains only one frame (the I-frame) every half-second or so and

interpolates the others, native HDV editing must cope with a major challenge:

Even a simple cut, unless executed at an existing I-frame, causes massive

recompression and artifacting in the subsequent frames. I chose the CineForm

codec, which is wavelet based and doesn't interpolate frames, to avoid this

problem and gain some elbow room for the intense process of compositing and

color-correcting.

I used the Sony HVR-M10U (Reviews, Sept. '05 DV) as my VTR for capture

and recording. The editing system was built around a Windows XP CPU with a

3.2 GHz Intel Prescott HT processor, 2 GB of memory, and dual-200 GB SATA

drives set up in a RAID-0 configuration for video storage.

I upgraded to version 3.1 of Aspect HD. The 3.1 version enabled batch

capturing, and the process went smoothly. Immediately after each capture, the

software automatically transcoded the original MPEG-2 file into the Aspect HD

codec. This process was roughly equivalent to real time on the 3.2 GHz

machine, which means that, when you use this method, you need to budget for

about double the time needed to capture your footage.

Once capturing and transcoding was completed, managing files and editing the

HDV material worked just like in any other format. Editing with the Aspect HD

codec was a satisfying experience. The response was snappy, and CineForm's

real-time engine really worked and allowed me to play back more layers and

effects from the timeline than some higher-end hardware-based systems.

Just one thing was missing-live playback to a real monitor. This can't be done in

real time via 1394 with Aspect HD because the software must transcode back

to an MPEG transport stream for display. A couple of options enable playout to

a color-accurate video CRT. If your computer has a motherboard with the new

PCI-Express slots, the Nvidia Quadro FX 540 allows a dual-screen editing

setup plus built-in HD monitor output. My machine didn't have a PCI-Express

bus, so I used the Matrox Parhelia board, which allows a dual-screen setup

plus program output to an SD monitor. Although I prefer true HD monitoring, I

was able to check scene-to-scene color with this setup.

The color-correction tools in Aspect HD, while not high end, are comprehensive

enough to allow pretty decent manipulation of the color in shadows, midtones,

and highlights. I tried to stick with the Aspect HD real-time plug-ins to give them

a thorough test, and found that the combination of the two (Color Balance and

Color Corrector) generally allowed me to do what was necessary.


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The Aspect HD real-time color-correction tools provided enough control for

the basic scene-to-scene color correction.

Fix it in post

I ran into two problems from the initial shoot that normally would have prompted

a reshoot, but since that wasn't an option, I decided to fix them in post and test

the limits of special effects in the HDV format. Remember when I said an

essential rule for shooting in HDV was, "Don't overexpose"? Well, the first shot

we did was a rack focus with a brightly sunlit window that was completely blown

out. The second problem was a shot where the camera crossed the line,

meaning that the character in the shot seemed to be facing the wrong direction

when intercut with the other camera angles used in the scene. I decided to useAfter Effects to fix both these issues. I planned to motion-track a fix for the

blown-out window and use a greenscreen shot of one character facing the

correct direction to replace the other shot.


To correct and over-exposed window a new exterior was motion-tracked in

After Effects. Luma Key and Matte Choker filters were used to make the

original clipped window transparent.

The Aspect HD footage imported correctly into After Effects, though it was

necessary to manually create a 1.33 anamorphic aspect ratio preset for the

footage to display properly. To correct the overexposed window, I prepared and

blurred a graphic of exterior foliage to seem out of focus. I placed it behind the

video footage (below it on the composition line). I applied the luminance keyer

with the matte choker to make the offending window transparent, and the new

exterior was motion tracked to match the foreground. Because the shot wasn't

designed to be tracked, it required some extensive hand-tweaking to get themotion just right, along with the look of the rack focus. The end result works

well, however, and doesn't call attention to itself.

A


B



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(a) The original footage with clipped exterior; (b) the finished effect is less

distracting.

The greenscreen shot was an interesting test of how far you can push this

highly compressed 4:2:0 format in the special-effects realm. We had high-res

still photos of every corner of the opulent living room set, and I simply used a

portion of one of those as the background plate. We shot the character (StanleyBaldwin) delivering his line in front of a green fabric backdrop with similar

lighting to the live shoot.


I created a greenscreen composite using the Color Range keyer in After

Effects. I used the matte Choker filter to smooth the jagged edges of the

matte and choke (contract) it to eliminate green edges.

In post, I tested several keyers, including Ultimatte AdvantEdge and Zmatte,

but got the best results on our footage with the Color Range Keyer and Matte

Choker in After Effects. The After Effects matte choker has improved in the last

few upgrades, and now can smooth out the jagged edges of low color sampling

schemes (such as DV 4:1:1 or HDV 4:2:0) effectively. Considerable choking

was necessary to achieve a clean edge. This worked nicely with Stanley

Baldwin, whose 1936-era slicked-back hair provided a fairly defined edge to

work with. On a subject with wisps of escaping hair or similar fine lines, those

details would have been lost.

I also needed to blur the edge of the matte considerably to match the other

hard edges in the natural picture. The initial matte had a crisp, well-defined

edge that looked artificial-too sharp-when composited into the HDV picture.

This is true to a lesser degree in less-compressed HD formats as well, but

mainly showed the limits of the Z1U lens. The HDV format can hold edges that

are much sharper than the standard lens can transmit.

Deinterlacing and conversion

Shooting in 50i was a decision I made in the beginning to preserve video quality

through to the end. Prepping the final sequence for DVD and film output

required a two-step process: First, I had to deinterlace the footage (from 50i to

25p), and then change the frame rate from 25p to 24p. (After I wrapped up

postproduction on Windsor Knot, a new version of Aspect HD was released that

would have made it a one-step process; see the "An Even Better Workflow"

sidebar.)

There are numerous techniques for deinterlacing footage, some of which are

terrible (field duplica-tion), others of which are a little better (field blending

methods), but the goal is to get good results without sacrificing vertical

resolution. After all, what's the point of shooting in a high-definition format if you

just go and toss away half the vertical detail in post?

The approach I used forWindsor Knotwas a "smart" deinterlace in After

Effects, which involves identifying those areas of a picture that have motion

between the fields and those that don't, and selectively applying field blending

only to the areas that have interfield motion. Another good option for smart

deinterlacing is DV Filmmaker from DV Film in Austin, TX (www.dvfilm.com).

DV Filmmaker is available for both Windows and Mac, and has a batch mode

that can process individual capture files. For all of the details on what


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constitutes a "smart" deinterlace, along with detailed instructions for setting it

up in After Effects, go to DV.com.

Once the material was deinterlaced into a 25p AVI movie, conversion to 24p

was done on a frame-to-frame basis by interpreting it as 24 fps in After Effects.

To stay in sync, the audio was slowed down 4 percent in Sound Forge

separately. The resulting 1440 x 1080 24p AVI file was ready for output to film.

For DVD output, the file was scaled in After Effects down to 720 x 480 with 3:2

pulldown applied. The end result-viewed on a 720p projector- looked very film

like. Surround-sound encoding was provided by the SurCode for Dolby Digital5.1 Encoder plug-in.

If you'd like to see Windsor Knot, you can learn more about the short and get a

DVD copy online at www.windsorknot.org.

Film blowup discoveries

The most intriguing test of the HDV format was the final stage-the output to 35

mm film. I sent identical 2-minute 24p CineForm HD codec files to DV Film in

Texas and Heavy Light Digital in New York. The file included a test shot with

high color and detail, and the greenscreen composite shot from the finished

short, as well as interior and exterior shots from the piece. Both labs printed the

file to Fuji 8522 negative stock and printed to Fuji print stock.

Because HDV-to-35 mm is still fairly new territory, I used two different labs to

discover what, if any, differences would show up in the final print. The results

point out the importance of running a test before choosing a lab.

We screened the test prints at the School of Filmmaking, North Carolina School

of the Arts, in a full-size theater. A panel of experienced film DPs was in

attendance, including Arledge Armenaki (Dennis the Menace, The Howling V),

Richard Clabaugh (Children of the Corn IV, Plato's Run, The Prophecy II), and

D. A. Oldis (Non-Abductees Anonymous). Armenaki and Clabaugh had both

taken part in a similar screening of DV-originated footage blown up to 35 mm a

couple of years ago.

The first print from DV Film was a bit disappointing. The DPs complained about

low black density (blacks looked dark gray instead of black), graininess,

pixelization, color blocking, and low saturation. The resolution of fine detail in

the test shot was lacking.

The print from Heavy Light Digital was much better. The print had good black

density, yet still had visible detail in dark areas. The color was better, and the

resolution was much sharper. Wide shots of the manor house exterior showed

detail in individual stones.

DV Film asked for another shot at the footage. The second print was better and

had higher overall detail. The blacks were denser-too dense, in fact, with a

subsequent loss of detail, and the color was artificially intense.

We watched the samples twice, pausing in between to talk about them.

Afterward, I asked the group to sum up their reactions to the best example, and

to HDV as a low-budget filmmaking format. Overall, they agreed that the HDV

blowup was substantially better than DV-originated blow-ups we had seen

previously, though the sample HDV clearly remains a step below true HD in

effective resolution. They thought it was likely that the inexpensive lenses used

on the lower-priced prosumer units contributed to the softer image when

compared with footage from a Panasonic VariCam or Sony FDW-900H; those

cameras are used with lenses that cost many times more than the total price of

the Z1U.

After some discussion, Armenaki and Clabaugh agreed that the blowup from

Heavy Light looked very much like a blowup from 16 mm. They felt that

origination on Super 16 would look somewhat sharper, but the parallel to 16

mm was strong. Armenaki went so far as to say that if he had been told it was a

blowup from 16 mm before screening the footage, he might not have noticed

the subtle cues that the footage had originated as video. All agreed that the

result was watchable, and that an average audience wouldn't notice the

differences if the other aspects of story and filmmaking craft were right.

It was interesting that none of the DPs noticed the greenscreen composite shot


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until I pointed it out. D. A. Oldis was impressed that the composite was so clean

when originating from a 4:2:0 format.

Budget considerations

Then came the difficult question: At what budget level should a filmmaker

consider HDV? This produced several answers and discussion about local

low-budget projects being shot on film. Armenaki and Clabaugh finally

suggested a feature project under $200,000. Both felt if they had higherbudgets, they would opt for renting a higher-end HD camera or shooting on

Super 16.

To answer this question, of course, requires a judgment call. There are many

other factors that would enter into a producer's decision to use HDV for a film

with potential for theatrical release. Many types of documentaries would be

better if they were acquired on video because it's more economical, allowing for

many hours of lengthy subject interviews. While a DP might want the higher

resolution and exposure latitude of a VariCam or CineAlta on a $500,000

project, the producer and director might opt to pay for higher quality talent in

front of the lens-or hire a larger number of high-quality actors. The producer

might even prefer to actually pay actors who otherwise would be working on

deferral (fat chance!).

Conclusions

My overall reaction to this trial project was real excitement about the potential of

the HDV format.I'll be even more excited when the manufacturers stop

squabbling and get HD DVD or Blu-Ray players shipping, so there is a viable

HD distribution and playback method. Editing was a far better experience than I

expected, and the end result was more filmic than I expected.

As people who have attended one of my workshops know, I pay a lot of

attention to compression artifacting. One of the very interesting discoveries I

made was that the MPEG-2 artifacting in most scenes seemed very similar to

film grain- very different from the obvious mosquito noise artifacting of DCT

compression in DV footage. Although the pseudofilm grain was more

pronounced than I prefer, it wasn't unpleasant or intrusive, and wasn't more

noticeable than the grain on some film stocks.

In retrospect, I would probably opt to use the less-aggressive CineGamma 1

setting on the Z1U or to change the gamma in post.

The format wasn't as delicate as I predicted, contrary to early fears about

dropouts. I ran initial tests using ordinary pro DV tape rather than Sony's more

expensive HDV tape, and saw no noticeable dropouts. Of course, for a more

extensive project, I'd probably want to use the HDV tape just to have the extra

bit of insurance against dropouts.

I'll probably buy one of the HDV cameras soon, but before I make my decision,

I want to undertake a similar test all the way to 35 mm film blowup. And I plan

on reporting the discoveries I make along the way, so stay tuned.

An Even Better Workflow: Converting 50i to 24p

After I completed post for Windsor Knot, CineForm released Aspect

HD 3.3 with some extra features-one of which is an on-the-fly frame

rate conversion to 24 fps. I tested this option by capturing some of m

original 50i footage and converting each clip to 24 fps (okay, really

48i) during the Aspect transcoding. Audio for each clip was slowed 4

percent during the transcode. The test clips were then batch-

deinterlaced in DV Filmmaker, and the clips edited on a 24p timeline.

The results were clean and the workflow was much better than the

somewhat cumbersome and multistage process I used on Windsor

Knot.


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I strongly recommend this workflow for PC users who want to end up

with a 24p product. I was less pleased with the results of Aspect 3.3'

direct conversion of CineFrame'd footage to 24p. Because of the

nature of CineFrame, the resulting frames lost about a third of their

vertical resolution. It's an easier work-flow, but at a price. Using the

50i-to-24p workflow instead with an interlaced camera like the Sony

Z1U will extract the highest quality possible from the format, with a

motion blur very similar to film.

Mac users still must under-take a more laborious conversion from 50

to 24p because Lumiere HD doesn't appear to have a similar frame

rate conversion utility. It's easy enough to simply reset the frame rate

of the clip, but the audio will still need resampling for the highest

quality finished product. DV Filmmaker for Mac can be used to

deinterlace, or you can use a plug-in like Magic Bullet.

HDV to Film: A Real-World Test (Bonus Tracks)

Now that you've read through the main article, here are some extra details and

information about the HDV-to-film process that just didn't fit into available space

for the feature.

Bonus Track 1: Reality Check

So, you're going to do a pizza-budget indie film with your pals in HDV, and

dream of doing a 35mm film blowup for distribution. That's great, and exactly

why I tested the production process with Windsor Knot. However, let's be

realistic. A quality digital blowup from HDV of a feature-length film is going to

run anywhere from $40,000 - $60,000 to start with. And then there's

distribution, without which only friends and relatives will see your film. In my

workshops on digital filmmaking, I make a pretty big deal about raining on this

parade -- because I've seen too many people hock everything and end up

bankrupt. Did you know that less than five per cent (that's 5%, or 1/20th) of

fully funded, completed feature films are picked up for theatrical distribution?

The percentage of films in the dreaming stage that will find distribution is

infinitesimal.

Dont let this stop you from pursuing your dream movie. However, I

recommend that most filmmakers plan for a film blowup -- but don't even think

of actually doing one until distribution is on the immediate horizon.

Bonus Track 2: Anatomy of An HDV Stream

HDV is a format agreed on by a consortium of manufacturers including Canon,

Sharp, Sony, and JVC. Panasonic is noticeably absent from the consortium

and appears to have no interest developing HDV products.

The format has been defined as a constant data rate, highly compressed

long-GOP MPEG2 stream that can be recorded on stock DV cassette tapes.

The overall datarate is about 19Mbps for 720p and 25Mbps for 1080i. The

color sampling is 4:2:0, similar to that of DVDs and unlike the 4:1:1 used in

NTSC DV. A 48kHz, 16 bit stereo audio stream is compressed with MPEG1

and is incorporated in the HDV transport stream. The resulting file can be

captured via IEEE1394 interface just like DV footage.

The MPEG2 compression used for HDV includes an IBP structure, including

both Predicted and Bidirectional frames. While this approach dramatically

reduces the bitrate for a given quality, it also means that editing is quite

challenging. The entire GOP, or Group of Pictures, must be decoded and held

in memory on the fly. When working a transition or multiple layers, the

computer may have to decode and hold as many as fifteen or twenty

decompressed frames in memory. The Sony Z1U uses a 15-frame GOP while

the JVC HD100 uses a shorter, 6-frame GOP.


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An illustration of the MPEG-2 format, with its IBP encoding structure. Only

the I-frames have all the information necessary to recreate the captured

image. The P and B frames have less information, and the correct cadence of

the I, P, B frames is required to play the footage correctly.

Heres a short glossary of MPEG2 and HDV terms:

GOP: Group of Pictures.

Short GOP: a Group of Pictures containing only an I frame.

Long GOP: a Group of Pictures containing more than one frame, whether IP,

IPPP, or IBP. A Long GOP may contain up to 18 frames in NTSC.

I-frame: Intra-frame, a frame containing all information necessary for the

codec to reconstruct the complete image. Each GOP starts with an I-frame,

which serves as a starting reference point for the following frames and which

allows random access points within a video stream.

B-frame: Bi-directional frame, a frame created by forwards and backwards

referencing of the P-frames and I-frames. Contains only predictive data about

changes from I and P frames, not enough data to make up an entire picture by

itself.

P-frame: Predicted frame, a frame created by using motion vectors to predict

the differences between it and the closest previous I-frame or P-frame.

P-frames, like B-frames, contain only predictive data.

Other Editing Options

ForWindsor Knot, I used Cineform's Aspect HD to transform my original

MPEG-2 HDV footage to an I-frame-only codec I felt would give me better

results in editorial. Cineform's products are PC based, and so they are a

natural choice for a Windows shop running Adobe Premiere Pro. But what ifyou're running a Mac with Final Cut Pro? FCP is now able to edit HDV footage


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natively, but if you want to use an I-frame-only solution similar to the one I used,

your primary choice for FCP is Lumire HD, an excellent plugin that provides

machine control, capture and automatic transcoding to the codec of your

choice. Frederic Haubrich of Lumire recommends editing in the

uncompressed 8 Bit Quicktime codec for highest quality, although his tests with

the new lossless Sheer Video codecs from BitJazz have been very promising.

Other options are out there, of course. Turnkey solutions like such as the

Matrox Axio and Canopus Edius NX for HDV are ready to go,. Software and

software packages like Sony Vegas and Avid (formerly Pinnacle) and Pinnacle

Liquid Edition can all handle HDVfootage can handle HDV, as can Avid's other

Windows-based NLEs (software or turnkey)..

Bonus Track 3: Demythologizing Deinterlacing

Deinterlacing techniques are a favorite topic of self-declared "experts" in web

forums, but unfortunately there's lots more smoke and verbiage in those

threads than actual illumination. So let's demythologize the subject here.

The basic deinterlacing provided on the timeline in most NLE packages is

simply field duplication. One of the fields (perhaps the even field) is thrown

away and the "kept" field (in this case, the odd field) is duplicated. In this

approach, lines 1 and 2 are duplicates, line 6 is a duplicate of line 5, etc. This

approach is quick-and-dirty and produces the least satisfactory result, since the

vertical resolution is instantly halved.

A slightly better result can be obtained with a technique sometimes called

"instant sex" (honest, I'm not making this up!) which is the deinterlacing version

of a color enhancement technique from a decade back. The video track is

duplicated and laid over itself on an NLEs timeline. The bottom track is

deinterlaced using the odd field. The top track is deinterlaced using the even

field, and then the opacity of the top track set to 50%. Various techniques

touted online call for different variations of boosted chroma, a touch of gaussian

blur, or some other combination of effects. The result is what is known as field

blending. It is an improvement over field duplication because it doesn't have

the jagged edges of the first method, but it still reduces vertical resolution byhalf.

The best deinterlacing (which some have called a "smart" deinterlace) involves

identifying areas of the picture that contain motion between the fields, and

creating a mask so that only those areas are affected. Inside that mask, the

fields are blended (resulting in convincing motion blur) but areas where there is

no motion are left unchanged -- and hence retain their full vertical resolution.

This method can be achieved in After Effects (as described in the article), but is

also used by DV Filmmaker and Magic Bullet for the 30P mode.

The method I used in the actual post for Windsor Knot was a "smart"

deinterlace in After Effects. After the final edit was completed, the entire file

was exported as an AVI and then brought into AE. There are two excellent

methods of field blend deinterlacing in AE, depending on the effect you want.

The first results in a sharper picture with less motion blur, the second results in

slightly more blur for objects in motion. In both, areas of the picture that do not

move between fields are unaffected and remain at full resolution.

Method 1: In the File menu, select Interpret Footage, and in the resulting

dialog box, select the proper field order.. In the case of HDV footage, choose

Upper Field First in the Separate Fields pulldown menu. Then check the

Motion Detect box immediately below the Separate Fields pulldown, and click

OK. Then, from the Effect menu, choose Video and apply the Reduce Interlace

Flicker filter to the entire program. Set the Softness slider to 0.7-0.9. Do not

exceed 1.0.

Method 2: In the Interpret Footage dialog, set Separate Fields to Off. The

Motion Detect box will be disabled. Then, apply the Video/Reduce Interlace

Flicker filter to the entire program. Set the Softness slider to 0.7-0.9. Do notexceed 1.0.


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Both of these methods work quite well; the second does begin to affect

non-motion pixels if Softness values of 1.0 or above are used. It does give

stronger apparent motion blur, however, and that was desirable for the look of

Windsor Knot, so I used method #2.

As mentioned in the article, aAnother good option for "smart" deinterlacing is

DV Filmmaker from DV Film in Austin, Texas www.dvfilm.com, and is available

. DV Filmmaker is available for both Windows and Mac., and has abatch mode

that can process individual capture files.

Bonus track 4: What about the CineFrame mode?

The Sony HVR-Z1U has a "CineFrame" mode which the manufacturer claims

creates a film-like motion. While the mode has some fans, most aficionados of

the film look decry the mode. CineFrame mode takes the interlaced video

and applies a 3:2 pulldown to it; indeed, this is similar to the manner in which

24 FPS film is transferred to video. However, since the Sony's CCDs operate

only in interlaced mode, the motion blur is the same as 60i, not like 24p at all.

And since the faked pulldown is achieved by tossing away fields periodically,

the resulting motion is jerky and irregular. The motion artifact shows up most

dramatically on camera motion that is usually avoided in 24p camera work; but

the irregular jerkiness is evident enough to make me avoid the mode. Inaddition, when CineFrame mode footage is deinterlaced to create true 24p, the

result has lower vertical resolution. In his tests, Adam Wilt also identified an

artifact that would show up occasionally where a field would be pulling color

samples from a previous field, resulting in an odd color flash in some scene

transitions.

Bonus track 5: What About 60i to 24p?

While there are some amazingly good methods of creating 24p footage out of

60i, they are very complex and involve sophisticated motion interpolation.

Examples would be the Snell & Wilcox Alchemist standards converter or the

Twixtor plugin. Any software that does not use motion interpolation (such as

Magic Bullet or CineLook) will accomplish the conversion by "throwing away" a

field periodically to make the frame conversion math work. The result is often

an irregular jerky motion that would not occur in real film, and which can be

quite distracting. This is why shooting in PAL 50i has always been preferred for

24p conversion, since the frame rate is so close that a frame-to-frame

conversion can be done without losing any fields or frames in the process.

The Rev. John Jackman has been shooting video for over 25 years. He was

one of the early cheerleaders of the DV format, but was pretty pessimistic about

HDV when it was first announced. You can hear him eating his words at The

Craft of Lighting forum atDV.com.

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