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High-Def Editing with HDV (5/2004)
by Douglas Dixon
Have you seen the new math: HD + DV = HDV?
We know what DV is: the popular Digital Video compressed format used for DV camcorders, DV cassette tapes, and DV clips stored and edited on computers. And we sort of know what HD is: High Definition digital video, although the realization of HD is a bit fuzzy, with a profusion of different types of HD television sets, HD cameras, and HD formats. Although we are sure of one thing about HD: it's expensive, and it requires a significant upgrade to production processes and equipment.
So what is "HDV"? It almost sounds like the best of both worlds, "HD for the masses" -- real high-def video, but stored on a common DV cassette, offering the promise of significant cost reductions and better accessibility with existing equipment. HDV is indeed a new format, announced in September 2003, that permits the recording and playback of high-definition video on a DV cassette tape. The first HDV product, the JVC JY-HD10U, is described as a "High Definition Mini DV camcorder," and records real HD (720/30p at 1280x720 pixels) on Mini DV cassette tape. Even better, you can get started with HD using the HD10U at a suggested list price of $3,995, and a street price under $2,800 (as of the end of 2003).
Be warned, however, that as with many new formats, existing production equipment and editing software is not compatible with HDV. As a result, early adopters have limited options for editing and archiving this material, and will need to struggle though some work-arounds in the production process. On the other hand, you're shooting HD for under $3,000!
The HDV format has been defined by four companies, Canon Inc., Sharp Corporation, Sony Corporation, and Victor Company of Japan, Limited (JVC). Further information is available from the HDV Format Information site (www.hdv-info.org).
The four companies intend to gradually incorporate features in future DV format-compatible products which enable them to recognize tapes recorded using the HDV format. They also will also propose the format as an international standard format.
Other companies that have expressed support for the HDV format include Adobe Systems Incorporated, Canopus Co., Ltd., CineForm, Inc., Hamamatsu Photonics K.K., KDDI R&D Laboratories, Sony Pictures Digital Networks, and Ulead Systems, Inc. (see below).
The basic idea behind HDV is to store high-def MPEG-2 video on standard DV media (DV or Mini DV cassette tape), and stream it across standard FireWire / IEEE 1394 interfaces.
The HDV video format supports MPEG-2 compressed video (MP@H-14), at two 16:9
and at both NTSC and PAL television rates (30 and 25 frames per second):
The HDV audio format supports MPEG1 Audio Layer II compression at 48 kHz sample rate, with 16-bit samples, stereo (2-channel) at 384 kbps data rate.
The HDV streaming data format over FireWire is a standard MPEG-2-TS (Transport Stream) format. Unfortunately, the MPEG transport stream format is typically used for transmission and not data file storage, and therefore cannot be processed directly by most video software applications. The common MPEG computer file formats are program streams (typically .MPG, with mixed video and audio) and elementary streams (typically .M2V, with just the video data). This is one of the issues limiting software compatibility with the format.
The first camera supporting HDV format was introduced by JVC in June 2003, the JY-HD10U (www.jvc.com/pro). The HD10U records in three formats: DV, SD progressive, and HDV formats, so it can serve as both a DV camcorder and a HD camera. The downside is that the HD10U is a single-chip camera, albeit with a 1/3-inch 1.18 megapixel progressive scan CCD, so can you give up some image quality (and light sensitivity) for normal DV shooting as a trade-off for the HD capability.
In the DV mode, the camera shoots standard mode 4:3 video (480/60i) with DV compression. In the SD progressive mode (480/60p) and HD progressive mode (720/30p, 1280x720), the camera shoots native 16:9 video with MPEG-2 compression (CBR/constant bit rate at 17.8 Mbps). The HD10U does not support the higher HDV 1080i format (1440 x 1080).
The HD10U also can do HD and SD format conversion, playing back to a standard or HD monitor via component output in standard or widescreen formats including 1080/60i, 720/60p, and 480/60i 4:3.
HD10U has a mix of professional and enthusiast video camera features, with a F1.8 - F1.9 optical zoom lens (10x), optical image stabilizer, and optional memory card for both still photo capture at up to 1280x960 resolution and MPEG-4 video capture.
One significant concern for any new camera that uses a newly-defined format is how to archive or even show the taped footage. JVC's current answer is to dub to a D-VHS recorder, which can interface via FireWire to stream the compressed MPEG data. While currently not a mass-market item, D-VHS recorders are used with HD television sets to play prerecorded D-Theater HD movies, and to record SD and HD digital TV broadcasts.
Once you shoot your video in the cool new HDV format, there still is the issue of how to edit it. Not surprisingly, existing video editing software does not support interfacing to this new format. In addition, editing MPEG video is tricky, and therefore not well supported by most tools. Furthermore, the MPEG-TS (Transport Stream) format used for HDV is not commonly supported by desktop tools. For the moment, then, editing HDV requires new tools or new approaches.
The problem with editing MPEG video is that the MPEG format compresses runs of consecutive frames together as a group to take advantage of similarities between adjacent frames. You therefore cannot directly access arbitrary individual frames within the compressed data. Some tools provide limited support for MPEG by only permitting editing at group boundaries. More sophisticated MPEG tools support frame-accurate editing by doing a lot of work behind the scenes to provide access to individual frames by decoding the entire group around them, and then re-encoding the group together again. If not done carefully, this kind of churn from re-compressing blocks of video can quickly create visible compression artifacts.
Not surprisingly, frame-accurate MPEG editing has been the province of special-purpose tools. JVC bundles one such tool with the HD10U, MPEG Edit Studio Pro 1.0 LE from KDDI R&D Labs of Japan (www.kddilabs.com). This LE bundled version supports basic 720p HDV editing, with a couple tracks, video transitions, audio fade and mixing, and rolling titles. It outputs only to HDV or MPEG-2 SD output (and only at constant bit rate). The full version of MPEG Edit Studio Pro 1.2 (list $1800) offers expanded editing and formats, with additional options for HDTV, MPEG-4, and streaming formats. JVC also bundles separate utility software for HDV input/output over FireWire to the camera, audio conversion to the HDV MPEG-1 format, and basic DVD authoring.
KDDI MPEG Edit Studio Pro
Of course, the advantage of using tools like MPEG Edit Studio Pro that work with compressed video is the significant savings in storage space: HDV at 720p requires only around 19 Mbps with MPEG-2 compression, compared to 25 Mbps for lower-resolution DV video (which uses less aggressive compression and compresses each frame individually).
The disadvantage is that access to this new format is locked into this one tool: you not only can't use your familiar tools, you can't play your clips on the desktop, or even preview them at full rate.
The first stage in the adoption of new technology is the "miracle it works at all" period, when it's so amazing to be editing HD video on the desktop that we put up with limited tools and ugly workarounds. But what we really want is to have HDV integrated into our existing production process, and accessible with our existing tools. This is the challenge that CineForm, Inc. has addressed with its new software products, Connect HD and Aspect HD (www.cineform.com).
CineForm has developed a mechanism for integrating HDV video into the standard Windows digital media architecture. With Connect HD, you can play HDV video right in Windows Media Player, and edit it using standard tools from Sony Vegas Video (www.sony.com/mediasoftware) to Adobe After Effects. Aspect HD then extends this capability by providing real-time accelerated HDV editing directly within Adobe Premiere (www.adobe.com/premierepro).
CineForm does this magic by introducing a new codec, a new compression format for HDV that stores the video in the standard Windows AVI file format. As a result, any Windows video application can understand the format, and use the CineForm codec to access the frames just like any other AVI file.
The CineForm codec, called CFHD (CineForm High-Def), is designed for editing HD video. The video is lightly compressed (at around 100 Mbps), so it still significantly reduces the demand on your PC's performance and disk space, compared to processing full uncompressed HD video. And it is designed for editing, so a conventional PC does have the power to not only edit but also provide real-time previewing of HD video. One way to think of this is that CineForm is to HD as DV is to SD. Both compress the video enough to allow you to edit it efficiently on standard platforms, and both are visually lossless, so the video retains the original quality all though the editing process right to the output. Yes, CineForm HD is less compressed than MPEG-2 for HDV, just as DV is less compressed than MPEG for DVD, but the trade-off is that both are therefore much more accessible and editable with standard desktop tools.
Connect HD, announced in December 2003, provides the base CineForm codec to enable processing HDV video with standard Windows tools. It also includes HDLink, the CineForm I/O software that connects PCs over FireWire to HDV camcorders and D-VHS decks and converts between the native HDV and CineForm formats. HDLink also provides scene detection and handles the garbage frames that can be generated by the camera between scenes, but it does not provide video monitoring on the PC during capture. Connect HD is available as of January 2004, stand-alone for $499 (suggested retail) or bundled for $799 with Vegas video editing software from Sony Pictures Digital Media Software (www.sony.com/mediasoftware).
Aspect HD, shipped in September 2003 for Adobe Premiere 6.5, and available in January 2004 for Premiere Pro, adds real-time editing and preview within Premiere for $1200. It adds a collection of optimized transitions and effects to Premiere so you can preview up to four HD streams in real time, plus transitions, effects, titles, and motion (on a powerful machine). These are native 16:9 effects, so the iris circle is a true circle and not an oval, even at the widescreen aspect ratio. The Premiere Pro version also optimizes three-point color correction.
To accelerate Premiere's motion effects, Aspect HD includes PZR (pan, zoom, rotate) effects to zoom into, pan across, and rotate the video in real time, with key framing. This is especially useful when editing the HDV video for SD output: You can pan a SD-resolution rectangle within the full HDV frame and extracting a full-res SD video. For example, a wedding videographer can set up a fixed HDV camera to shoot the ceremony, and then do all the panning and zooming in post-production, while maintaining full SD resolution.
When you finish editing, you can export to any format using the standard Premiere options. For playing HD on the desktop, you can export to Windows Media at the same 720/30p format. For saving back to the HDV camcorder or to a D-VHS deck, you can use an updated version of the Adobe Main Concept MPEG export module to convert back to MPEG-2-TS format.
While today's standard PC's are finally powerful enough to play and edit DV video off the shelf, you will want a slightly higher-end system to handle HD. The good news is that you don't need an extreme machine, but those HD frames are definitely bigger for processing in memory (1280 x 720 vs. 720 x 480) and the video files are significantly larger for pulling from disk (around 100 Mbps for CineForm vs. 25 Mbps for DV and 19 Mbps for MPEG-2-TS).
For Aspect HD, CineForm specifies at least a 2.4 GHz Pentium 4 PC, with 512MB PC2100 DDR memory, and a dedicated single 7200 rpm disk. For maximum performance, you'll need a RAID disk configuration to be able to stream multiple files at the same time, plus more processing power to provide real-time overlays and effects. To achieve real-time performance with 3 to 4 video streams CineForm recommends at least a 2.8 GHz Pentium 4 PC with Hyper-Threading technology, with 512 MB 1066 MHz RDRAM or 800 MHz dual-channel DDR SDRAM, and at least two 7200 rpm disk drives organized as RAID 0, with each file striped across multiple disks for faster access.
One source for high-performance digital video editing systems is 1 Beyond (www.1beyond.com), which offers a wide range of complete desktop and laptop PCs. These systems are optimized for the demands of HD editing, fully configured with processor, memory, disk drives, computer interfaces, video connectors, and even bundled software.
For mainstream videographers and enthusiasts, HD has seemed like an exotic future possibility, just now reaching the wide public with still-expensive HD televisions. And HD production certainly has seemed to be so outlandishly expensive to be an option only for network-type productions and digital filmmaking.
The development of the HDV format using standard DV tapes, and the availability of the JVC JY-HD10U camera at under $3000 significantly changes the landscape. Now you not only can shoot 1280x720 HD video, but you can edit it on the desktop, and even use your existing tools with the CineForm format.
Shooting in HDV also can create interesting new service options for corporate and event videographers, even if your customers do not have a D-VHS player or even a true HD television to take full advantage of the format. You can deliver full widescreen HD to the desktop (or laptop) in formats like Windows Media, and then connect to a projector to display to a larger audience. You also can author 16:9 DVD productions from HD, optimized to play on set-top DVD players connected to widescreen digital TVs. Or you can pan and zoom in the HD frame to edit high-quality standard-definition productions, exported to formats such as DV and DVD. Plus, you can archive the HDV footage and offer the future option to create a full HD production.
Even as first products, the JVC HD10U camera and CineForm software can integrate well into your existing production process. The HD10U has the flexibility to shoot DV and SD as well as HDV, and CineForm's Connect HD and Aspect HD then allow you to edit HDV with standard Windows Media tools. HDV is actually already in better shape than the early days of DV, as today's higher-end PCs can capture and convert formats in real time, and provide real-time preview of multiple channels and effects. Do the math for yourself: HD + DV may well equal something you should consider jumping into soon.
JVC America / Professional Products
JVC Professional - JY-HD10U
KDDI Labs USA
KDDI R&D Labs of Japan
KDDI Labs - MPEG Edit Studio Pro
CineForm -- Aspect HD, Connect HD
Adobe Premiere Pro
Sony Pictures Digital Media Software - Vegas
1 Beyond - Digital Video Systems