High Definition From Near to Here
Written by David Tames | Posted by: Anonymous
On June 16th the New England Chapter of the Society of Motion Picture Engineers (SMPTE) held the Second Annual HD Boot Camp 2005 at Bunker Hill Community College. The event brought together members of the production and postproduction community to share knowledge and learn about the latest cameras and products for use in high definition production from a range of vendors and practitioners. Here are some highlights from the event.
HD Cameras from A-to-Z
John Rule, President, Rule Broadcast Systems, presented "HD Acquisition from A-to-Z," an elegant presentation showing the wide range of cameras available today for HD production and beyond. He also helped put HD in perspective for producers. Rule suggested that HD is now being used in "all manner of projects" and that even for standard definition projects, shooting in HD provides producers of projects that have a long life expectancy "future proofing" and assures them that "two to five years from now the project will still be relevant." Rule also suggested that shooting in HD provides the opportunity to "ask yourself one less question you have to ask yourself later in life."
Discussing his experiences at NAB 2005 back in April of this year, John said that Sony’s new HDV Camcorder, shown at NAB 2004 and released in November of 2004 created an "iPod like frenzy" at NAB 2005, with numerous vendors showing devices and accessories for the camera all over the show, creating the "same excitement and buzz," and while he did not see any "tiger skins" for the camera, the range of accessories and third-party support came close.
The range of HD cameras starts with prosumer 1/3" and 1/2" 3-chip cameras in the $3,500 to $10,000 range like JVC’s GY-HD100U Pro HD and Panasonic’s AG-HVX200 DVCPRO HD camcorders and moves up through the professional 2/3" 3-chip cameras from Sony, Panasonic, and Thomson in the $40,000 to $120,000 and beyond range. There’s an emerging category of even higher-end cameras designed for digital cinema acquisition that go beyond HD in terms of resolution and design criteria like the Kinetta, Dalsa, Arri D20, and Panavision Genesis. These cameras are designed with large single-chip sensors and thus, by eliminating the prism of 3-chip cameras, allow the use of traditional 35mm film lenses. These cameras offer the optical qualities of 35mm cameras and a dynamic range and color space that is approaching that of film and promises to seriously close the gap between 35mm acquisition and digital cameras. Some of the demo footage I’ve seen shot with cameras like the Dalsa and Viper has been stunning.
On Projection and Formats
Vincent Froio and Steve Sarafian, Sales Support Engineers with Sony Broadcast, provided a visual comparison of various HD recording technologies and discussed the differences between between Sony’s HDV, HDCAM, and HDCAM SR formats. The most exciting part of their presentation was watching sample clips projected with Sony’s new 4K SXRD projector designed for large venues. The images looked amazing in the large theater setting used for the demonstrations. Unlike DLP projection systems which are the defacto standard today for digital cinema theaters, there was absolutely no perception of a grid or pixels with this projector, even while sitting in the front row. The images had great contrast with plenty of detail in the shadows and clean highlights. Sony’s SXRD technology is very similar to JVC’s D-ILA projection technology. Anyone who might have been skeptical of the claim that digital projectors will exceed the standards of 35mm projection would find themselves thinking long and hard after this demonstration.
The HDV format is Sony’s offering for prosumer camcorders that records a 1440×1080 frame, subsamples color with a 4:2:0 profile and 8 bit quantization, and uses MPEG-2 compression to reduce the data rate down to 25 Mbit/sec. In English, this format compresses the video substantially in such a way that there are many visible artifacts but you don’t notice most of them with average motion video sequences, and given the cost of the cameras and the tapes, there is little room for complaint. One limitation of HDV has been a dearth of native editing solutions, however, Apple’s Final Cut Pro 5 now supports it and support from Avid is imminent. Solutions are also available from a number of other non linear editing (NLE) vendors.
The HDCAM format is Sony’s workhorse for professional HD acquisition recording a 1440×1080 frame (upconverted to 1920×1080 on output), subsampling color with a 4:2:2 profile and 10 bit quantization and uses MPEG-4 studio profile compression at a 4.5:1 ratio to reduce the video data rate down to 180 Mbit/sec. In English, it compresses the video in such a way that very few artifacts are visible and is suitable for a wide range of productions. Keeping the data rate down to 180 Mbit/sec does result in some artifacts in the image.
The HDCAM-SR format is designed for high-end professional productions demanding something even better than HDCAM. This format offers a full 1920×1080 frame, a choice of either 4:2:2 or 4:4:4 profile and 10 bit quantization and uses MPEG-4 studio profile compression at a 4.2:1 (in 4:2:2 mode) or 2.7:1 (in 4:4:4 mode) compression ratio recording a whopping video data rate of 440 Mbit/sec to tape. In English, this format compresses the video in such a way that practically no artifacts are visible and will make even the most discriminating cinematographer or video engineer happy. In comparison to MPEG-2, MPEG-4 studio profile is a compression algorithm that provides visually loss-less recording of full bandwidth images.
Sony and JVC bet on HDV
Ken Freed, Regional Sales Engineer, JVC Professional Products, gave a presentation titled, "HDV – Effective Bandwidth HD" in which he suggested that using MPEG-2 compression as the basis for the HDV videotape format provides users with a high-quality and cost-effective approach for recording HD using either the HDV1 or HDV2 specification. HDV1 (used by JVC’s GY-HD100U ProHD camcorder) is a 1280×720 progressive scan format with a data rate of 19 Mbit/sec using MPEG-2 6-frame GOP compression. HDV2 (used by Sony’s HDR-FX1 and HVR-Z1U HDV camcorders) is a 1440×1080 interlaced scan format with a data rate of 25 Mbit/sec using MPEG-2 15-frame GOP compression (Check out the link to "The MPEG Standard" at the end of this article for an explanation of MPEG terminology). Freed suggested that by building the HDV format as an extension of the existing 25 Mbit/sec DV tape format, vendors can offer HD image quality using relatively inexpensive miniDV video cassettes. Freed acknowledged that many critics of the HDV2 format cite motion artifacts as the down side of using MPEG-2 with a long 15-frame GOP structure, however, he suggests these are rare in practice and that when JVC’s GY-HD100U ProHD camcorder hits the streets later this summer, we’re going to be very happy with the image quality and reduced visibility of motion artifacts thanks to the HDV1 format with a shorter 6-frame GOP structure.
Panasonic takes the road less traveled
The presentation "There’s HD, HD and then there’s HD" by Steve Mahrer, Director of Product Engineering, Panasonic Broadcast, offered a counterpoint to Freed’s presentation. Mahrer’s presentation covered four key points. First, Mahrer suggested that HD is becoming a general term for a range of high-quality formats that include digital intermediates from 35mm film, HD-D5, DVCPRO HD, HDCAM, HDCAM-SR, HDV, etc. It’s all HD, yet each format has it’s own unique characteristics and design trade-offs.
Second, Mahrer argued that HD image streams are too complex to be squeezed into a 25 Mbit/sec tape format without sacrificing image quality, and this is why Panasonic chose to implement the 100 Mbit/sec DVCPRO HD format (current used in their high-end VariCam HD camcorder) in their sub-$10K AG-HVX200 HD camcorder due out before the end of the year. So, what will you record this 100 Mbit/sec DVCPRO HD format onto? The DVCPRO tapes used in the VariCam will not cut it, they are too large and expensive for a small hand-held camcorder. More on this below.
Third, compression technology is rapidly moving forward, and compression based on the new H.264 codec (already supported by Apple in the latest version of DVD Studio Pro) offers spectacular HD quality with a low data rate in the range of 6 to 8 Mbit/sec. This means it’s possible to use existing DVD-R disks to deliver HD content. Some DVD players capable of displaying H.264 encoded materials were shown at NAB with the promise of rapid entry into the marketplace. And you can already display H.264 materials directly from a Macintosh or PC. Earlier in the day Mahrer told me, "MPEG-2 has reached the end of its usefulness, today with new codecs like H.264 you can do so much more." And more it does, H.264 provides quality SD or HD video at approximately half the data rate of MPEG-2. H.264 has been ratified as mandatory in both the new HD-DVD and Blu-ray specifications for High Definition DVDs. But since you can use today’s DVD-R technology as a transport medium for H.264 movies, there is no need to wait for adoption of HD-DVD or Blu-ray to deliver HD content.
Fourth, Mahrer discussed Panasonic’s alternative to videotape: P2 cards. These are PCMCIA form-factor cards with four SD semiconductor memory cards ganged together internally in a RAID configuration. These cards can easily keep up with the 100 Mbit/sec data rate of the DVCPRO HD codec. 8 GB cards will hold 20 minutes of 720P video and will be introduced at a price around $1,900. each. Prices are expected to drop, tracking the gradually falling prices of semiconductor storage. If you get a AG-HVX200 HD camcorder with two 8 GB card, that brings your total camera system price tag close to $10,000.
The idea is you will record to these cards and download video from the P2 cards to a laptop in the field, archiving onto dual-layer DVD-Rs or external hard drives, eliminating the use of tape in your workflow. You can download video from an 8 GB card to a laptop in about five minutes, so your archiving can stay ahead of your recording. While at first this sounds very expensive, a quick calculation on a spreadsheet yielded the following factoid: the P2 approach is only 20% more expensive that shooting HDV videotapes and archiving to HDV videotape dupes, as you have to purchase an HDV deck for video ingest into your editing system if your camera is going to be out in the field shooting while the editor captures media. Actual costs will vary based on production and postproduction workflows.
HDV on TV
The liveliest presentation of all was a screening of an episode of "Chronicle" titled "HD 101" that aired March 30, 2005 on WCVB Channel 5, Boston, along with a behind the scenes piece on the making of "Chronicle," followed by questions and answers with Art Donahue, Producer, Editor, and Cinematographer of "Chronicle," and Mike Keller, Director of Engineering at WCVB. Art introduced the piece by saying that HD, and especially Sony’s new HDV camera, has "completely changed what I do" and he is thrilled because he can "take this camera just about anywhere" and it allows him to "tell stories without breaking my back." The episode, most of it shot by Donahue using Sony’s HDV camera, explores the current state of HDTV technology and included a segment on "The Legend of Lucy Keys," a local feature shot in HD with Panasonic’s VariCam directed by John Stimpson, featuring Julie Delpy, and produced with Moody Street Pictures. Stimpson’s film was edited in native DVCPRO HD with Final Cut Pro. Donahue edits "Chronicle" with an Avid on his laptop using digital proxies after dubbing the Sony HDV tapes to DVCPRO HD. The DVCPRO HD tapes are later used for the final HD online edit. Donahue was happy to say that "no longer are logistics of getting the camera where I want a major part of my job." And as a producer, Mike Keller said he liked the new small cameras because they are "a tool that matches the things we want to do," and quipped, "we can’t shoot stories to fit the large camera."
Free and Open
This special SMPTE meeting was free and open to the public and for that I congratulate the SMPTE New England Chapter and Bunker Hill Community College for making this very informative event possible in such a wonderful setting easily accessible via mass transit. I hope there will be a third annual event.
There were three presentations on the agenda that I was unable to attend: Ken Hunold, Engineer, Dolby Broadcast Applications, discussed the technology behind their new Dolby Digital Plus audio coding technology for digital television and HD disc formats. Jed Deame, General Manager, Teranex, discussed format conversions between SD and HD video formats and presented an approach for evaluating their quality. John Pierce, Director of Sales, Leader Instrument gave a tutorial titled "HD & Digital Primer" explaining the basic technology underlying the new high definition formats.
For more information:
Apple DVD Studio Pro, Final Cut Pro http://www.apple.com/finalcutstudio/
Blu-ray Disc Association http://www.blu-ray.com
Dalsa Digital Cinema http://www.dalsa.com/dc/index.asp
H.264 FAQ http://www.apple.com/mpeg4/h264faq.html
HD DVD Promotion Group http://www.hddvdprg.com
JVC ProHD Camcorders http://www.jvc-victor.co.jp/english/pro/prohd/index.html
New England Chapter of the Society of Motion Picture Engineers (SMPTE) http://www.v-site.net/smpte-ne/
Panasonic DVCPRO HD Camcorders http://www.panasonic.com/business/provideo/cat_cam_systems.asp
Panasonic P2 Cards http://www.panasonic.com/business/provideo/p2/index.asp
Rule Broadcast Systems http://www.rule.com
"The MPEG Standard" (explaination of how MPEG works) http://cnx.rice.edu/content/m11144/latest/
Thomson Broadcast & Media Solutions Viper http://www.thomsongrassvalley.com/products/cameras/viper/
Sony Sony HDV and CineAlta Camcorders http://bssc.sel.sony.com/Professional/production/
Sony SXRD 4K Projector http://bssc.sel.sony.com/BroadcastandBusiness/DisplayModel?id=79210
WCVB Channel 5, Boston, "Chronicle" http://www.thebostonchannel.com/chronicle/index.html