high definition editing in post

Developing a high definition post facility here in Dallas has taken eight years, hundreds of thousands of man-hours and millions of dollars. Every project
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Developing a high definition post facility here in Dallas has taken eight years, hundreds of thousands of man-hours and millions of dollars. Every project has peculiarities and nuances that push you into new areas of HD and leave you excited about the next assignment. Recently electronics giant Texas Instruments wanted to do a multilayered, interactive-style HD video project. "Your Personal DLP" is a scripted example of high definition interactive television that Texas Instruments is using for display on their Digital Light Processing (DLP) high definition monitors.

Off-line for HD Off-line work on the project was done in Final Cut Pro (FCP). Two ways of capturing video into FCP are Firewire or Analog. In this instance, we used DVCAM via Firewire and had the HD format downconverted to Beta SP. We kept the 16:9 format by letterboxing the images. We chose to do the project in DVCAM because of inadequate information from video card manufacturers and local video systems supply vendors. We would have preferred to eliminate the DVCAM step and capture directly from the downconverted Beta SP tapes. However, we were unable to upgrade our Macintosh G4 Final Cut Pro system to include analog (Beta SP) in November 2000. Directly after the DLP project, we upgraded our system with a minimum of help from manufacturers or vendors.

There are problems with downconverting HD to analog. The most apparent problem is the image quality. When viewing analog downconversions from HD, it is difficult to see full details in the image. The image looks great in analog NTSC, but you may miss imperfections in the HD video and even images in the distance. This can be a big problem when finishing in HD. Also, graphics in standard definition do not necessarily look as good as they will in HD. Off-line editors depend on the producers to view all material in HD prior to downconverting to make sure the images to be downconverted are of the highest quality and the best for use in the project. Failure to produce with image control in mind can lead to longer online sessions.

This is the importance of off-line - to save costs and time in the online process. Searching for images in the online is cost prohibitive and wastes valuable resources. The organization of graphics for an HD project is of utmost importance. The graphics are made for 16:9 HD 1920 x 1080. In the off-line process, we used 4:3 DV NTSC 720 x 480 (FCP offers 16:9 editing). We do believe 16:9 will be the format of the near future; however, in most instances, we are still editing in 4:3 (720 x 480 or 720 x 486) format. We have not found it cost effective to purchase 16:9 equipment at this time. In order to optimize the process, the graphic artist needs to change the ratio to 4:3 (720 x 480) for DV and 720 x 486 for standard definition. The HD online needed a matte made for each graphic (white on black); in the off-line, we needed an alpha channel attached to the graphic to speed up the off-line rendering. The graphic artist not only changes the aspect ratio, but also includes an alpha channel for off-line. We found it important to do all graphics in the off-line first, both for organization and to check for mistakes. It is costly to find these mistakes in the online process.

"Your Personal DLP" consists of three video layers. The first is a full screen background layer of high definition sports footage, nature images and travel footage. Layer two consists of the interactive character "OK Bob." The third video layer contains all the graphics and interactive menus used for the interaction between the OK Bob character and the interactive (voiceover only) television viewer.

When off-line editing was done and approved by the client, we broke down the layers in FCP for the edit decision list (EDL). The first EDL, V1, contained all B-Roll. The second EDL, V2, contained all graphics. The third EDL, V3, was for the interactive character OK Bob. The three EDLs represent the three video layers normally used while layering in nonlinear systems. All EDLs were then sent to Tim Werner, HD VISION's senior online editor, via e-mail. The final step was audio mixing of B-Roll natural sounds and SFX. We did not mix down OK Bob's voice because Tim Werner had already flanged his voice. We based the final audio mix on OK Bob's level. The levels of natural sounds and SFX needed only minor adjustments during the final audio mix. We passed the audio mix to a Beta SP tape that could then be brought into the HD online suite and mixed down to the final master of the DLP OK Bob project. The digital music was added in the online, so the final audio mix would retain quality. To keep optimum quality, audio should be kept in its original digital format. When passing audio back and forth between digital and analog, you inherit many problems, from distortion to pops and cracks and degradation of the signal.

Building graphics for HD Working as a production designer and art director on HD projects requires rethinking old design issues. Barry Phillips' move from editorial and advertising illustration to film art direction made him acutely aware of the benefits of illustration translating directly into film. But the format of film seemed to cloud a lot of the detail and texture, and he became frustrated by the camera missing so much of the effort put toward detail.

His introduction to working in HD came a year ago, with a position as Supervising Producer/Production Designer on the television pilot "Texas Tales and Legends" - a period look at Texas during the 1930s and 1940s. He went into the project with much anticipation and no experience with "HD do's and don'ts." He knew that he wanted to keep close watch on texture and color palette - especially working with reds and black and patterns that vibrate on screen. For the open, he used old photos in a moving montage with lots of rich color enhancement, but still retaining the look of the "old" sepia tones. During shooting, the beauty of the detail that emerged from a sensitively lit set was evident. The HD sensitivity to light is especially wonderful in the night shots. Some of these scenes tend to be over-lit because of the need to do so when shooting regular film or video. He loved the period detail, the colors that stayed constant and the expanse that the HD format created. Nuances that happen all on their own had now found a visual place to live on the screen.

In the HD VISION projects, the HD format complements an overall reach for perfection in design, color and look. We wanted the graphics for Texas Instruments and Travelbyus Inc. to have a retro art deco feel combined with the contemporary flair that HD design gives. HD allows designers to work with delicate, fine line design and use colors that are exactly what is wanted when displayed, with no variation from the original intent. The look is crisp, clean and the format is handsome in its wider and broader sweep across the screen.

As a graphic artist with years of experience in illustration and designing for print, Blue Bliss scrutinizes everything with an eye for detail - be it paint on paper or pixels on a monitor. When designing for NTSC, you have to throw half of that detail away, thinking in terms of large readable text and avoiding that major taboo, bright red.

In her recent work for HD VISION, she found that she got back everything she had lost to NTSC. She was able to use fine lines, subtle color changes and delicate details, almost at the level of print graphics, without having to "dumb down" the images for television. This was demonstrated by HD VISION's recent projects for Texas Instruments and Travelbyus. The team created two video presentations, both with graphics in HD. One would also be downconverted to NTSC to be used by the client for other applications. Knowing this beforehand, Blue Bliss had the whole luxurious width of the HD horizontal format to play with, but still had to confine name keys and the like to the NTSC safe title area, centered within the HD area. In a test of the graphics in NTSC, the huge difference in image quality was apparent. Slim, elegant name keys had to be changed into comparatively large, crude ones for readability. It did seem a shame to have to build NTSC's limitations into the design of an HD piece.

Another interesting issue that emerged during the course of the two projects is the nature of relationships - not only between people working together for the first time, but also between machines and software. For instance, when art directors created Photoshop files, they had to keep in mind that the online editor needed to have two PICT files for each graphic - one full color and white on black for the alpha - at 1920 x 1080 pixels. Also, the off-line people needed the files sized to 720 x 480 for their equipment. Another issue the art directors had to consider was the fact that when their PC files were loaded onto the Mac machines used by the off-line editors, all of the file names were truncated to just a few characters, making them unusable for identification.

It is evident when working in HD, as in any other project, that while you can do your best to plan a job up front, when entering new territory unknowns can and will emerge to ambush you. As the team works together on future projects, they will build a foundation of shared knowledge and experience that will make things go more smoothly. A continuing dialog between teammates also facilitates developing new and better ways of getting results, and the kinds of creative ideas that only come from the process of doing.

Online editing At HD VISION we can record to three different HD formats: Sony HDD 1000 one inch at 1035i, Sony HD Cam at 1035i or 1080i, and Panasonic HD D5 at 1035i or 1080i.

HD VISION opened its doors for business in 1993 and has a very large library of high definition footage. A lot of this material is 1035i. It is used with 1080i footage when clients request use of this material. If a majority of the material in a project is 1035i, with a client's approval, a 1035i master will be edited. If most of the footage is 1080i, a 1080i master will be generated. The difference - 45 lines - is really minimal, especially for broadcast masters, where most of the additional 45 lines of a 1080i master at the top of the image are lost in transmission. Both formats have 1125 total scan lines. With 1080i the vertical interval is smaller.

We do have to be careful when using 1080i and 1035i material in a master, so field interchange problems do not occur. We use a Snell and Wilcox HD 1024 switcher in our edit bay. When cross point inputs are set manually at the appropriate line input or set on "auto," this switcher will align 1035i and 1080i inputs properly so that both formats can be used when mastering at 1035i or 1080i.

If a client needs 1035i footage converted to 1080i so that the 45-line gap at the top of the frame is filled, Werner will use the optional 502 board available in Sony HDW 500 HD Cam decks to accomplish the conversion. There are ways of making the 1035i / 1080i situation work properly, and this will become less of a problem as more and more native 1080i footage is recorded in high definition production.

One online editing procedure is to have off-line editors e-mail their edit decision lists (EDLs) to the online editor a few days before the edit session if possible. This allows time to download the list and double check the EDL for readability in the Sony 9100 online editor. We routinely have clients that travel great distances (from Germany, Scotland, California, etc.) to edit with us here at HD VISION in Irving, TX. This helps to minimize any possible EDL problems well in advance of someone's arrival so that any glitches can be taken care of while a client is still at their home location.

When we are mastering to HD Cam and will be using the deck's pre-read capability, the EDL is run through the Software Grille's Pre-Reader program to modify the lists for a more efficient high definition linear online edit. This was the case with the Texas Instruments "Your Personal DLP" project.

Off-line editors Dan Whiteman and Mike Losurdo formatted their Final Cut Pro EDLs with multiple B-Rolls for shots coming from the same reel that require dissolve type transitions. In this way, the EDLs could be modified properly via Pre-Reader for a pre-read online edit. Pre-Reader has been used many times in the past with Avid-generated EDLs and, in this project, was also shown to work well with the Final Cut Pro edit decision lists.

Dan Whiteman e-mailed Werner the three EDLs that corresponded to the three video layers. Werner then put video layer one - the background layer - through Pre-Reader for a sequential "A" mode pre-read edit, which allowed for proper color correction on adjacent shots.

Whiteman also supplied him with a Beta Cam SP of the approved off-line master. Werner has control via the Sony 9100 editor of a Beta Cam SP machine in the HD online edit bay, as a source machine that is fed directly into the only NTSC monitor in the room. This letterboxed off-line master was only a visual reference and was not fed as an upconverted source into a cross point on the HD 1024 switcher. It was used in conjunction with the edit decision lists.

The Snell and Wilcox HD 1024 video switcher in use at HD VISION has seven color correctors. These color correctors offer RGB brightness, gamma and pedestal adjustments that can be made separately or in tandem. YPbPr controls are also provided.

HD images offer a lot more contrast than NTSC images and a much larger color palette. A single frame of high definition contains four to six times more picture information than NTSC. Even subtle color correction adjustments are very noticeable in high definition. In many cases just a small gamma adjustment (black stretch) will cause a significant improvement in the look of a properly recorded HD image.

Werner uses a Tektronix RGB high definition waveform monitor in conjunction with a Sony 28-inch HD color monitor to color correct HD footage. There is no color subcarrier or color frame issues to deal with in high definition and therefore no need for a vectorscope. Color correction settings can be stored as DMEMs in the HD 1024 DMEM registers. Notes are added to edits in the online EDL regarding DMEM registers that correspond to color correction settings, so that they can be recalled and adjusted if necessary.

After editing the first video layer of "Your Personal DLP" Werner cloned layer one to an HD D5 tape. Gary Sextro, Texas Instruments' executive producer on the project, wanted each video layer as a separate element for future editing flexibility.

After cloning layer one, he used the layer two EDL to pre-read the OK Bob character in the upper righthand corner of layer one of the HD Cam master. He chroma keyed OK Bob and added a DVE warp effect to his image. This effect, along with the flanging of his voice, gave OK Bob a slightly ethereal look and sound.

Chroma and luminance keys are easier to do in high definition, once again because of the additional picture information in each frame of HD. Keys have more range, and with the Snell and Wilcox switcher editors can chroma key just about any color. We used standard chroma key blue as our key color for the OK Bob character. The HD 1024's chroma key adjustments allowed Werner to feather the edges of OK Bob for a great-looking chroma key.

The Snell and Wilcox chroma keyer offers a wide range, and it turns out you really need it. The great thing about HD is beautifully detailed images. The bad thing about HD - not really all that bad but undeniable - is that you cannot take any shortcuts or hide anything when it comes to proper keying or compositing. If you do you will see it. In high definition, NTSC keying and compositing shortcuts do not work!

After the OK Bob character was added to the HD Cam master and cloned to HD D5, Werner used the EDL for video layer three to pre-read the Photoshop supplied graphics and interactive menus onto the master. These were luminance keyed with corresponding white on black mattes. Once again subtle clip and gain adjustments to the luminance keyers on the Snell and Wilcox switcher made for significantly noticeable changes to the look of the key in the HD image. So much so that we have since moved the Snell and Wilcox HD 1024 switcher closer to the edit bay's 28-inch Sony HD color monitor to be able to better scrutinize key clip and gain adjustments.

These adjustments are especially important because a high definition image may wind up being projected onto a large viewing screen - sometimes as wide as 32 feet. This was the case with the Texas Instruments project. An even slightly misadjusted chroma or luminance key in a high definition image will not look good, and can become even worse if it is projected onto a large screen. Especially if it is projected with a high definition video projector that uses the Texas Instruments DLP system.

When he finished pre-reading the graphics onto the HD Cam master, Werner made one final clone onto an HD D5 of the completed HD video edit. Then he did a stereo mix of the music, the OK Bob flanged audio, and the stereo sync and voiceover audio (from the Beta Cam SP off-line master)onto the HD D5 clone of the final HD video to create a duplication master that was delivered to Texas Instruments DLP Division.

Final project review Gary Sextro, Texas Instruments DLP Division, reviewed the completed project on a Panasonic 52" DLP (720p) rear view HDTV. He was impressed with the crisp graphics and audio and of course the picture quality. As a side note, the project was then viewed at Texas Instruments' in-house theater using their DLP technology 1080i projector system. The video was shown using an HD D5 VTR. Even after enlarging the picture onto a 30-foot screen the graphics and picture quality remained intact. This is one aspect of HD that is often overlooked. As Kevin Caddell, chief engineer remarked, "While in the production process always...think big." Historically, completed HD projects have been viewed through consumer-sized display systems. Larger venues, such as e-cinema, take advantage of HD's increased resolution and can show the same material without degradation or loss of resolution. The project was aired at CES and will be shown again at NAB.

The future This is the only industry that is still in its infancy after more than fourteen years of development. We will continue to research and develop new technologies to enhance our production capabilities. Through future expansion and expenditures we will bring some of the strengths of nonlinear editing to the table to enhance our real-time linear editing capabilities. One is the addition of a new graphics workstation with Adobe's After Effects and Pinnacle's Commotion to do roto-scoping and high definition after effect composites that we can then render to a high definition digital disk recorder. While there will always be differing opinions and solutions to the many obstacles we face in high definition production one thing is sure: It will only get better from here. That is what it is all about.