GV July 1998
To DVD or Not to DVD That is the
By Sheldon Liebman and Ralph LaBarge
Last October, Government Video looked at CD-ROM authoring hardware and software. This technology offers a fast, easy and inexpensive method of backing up and/or sharing large amounts of data with other people.
Today, lots of people are wondering if CD-ROM is about to go the way of the 5 1/4" floppy disk. The "hot" technology of the day is DVD, which either stands for Digital Video Disc or Digital Versatile Disc, depending on whom you ask. Every week, DVD players are advertised at electronic stores as a "must-have" product for anyone interested in going to the next level of television viewing or as the core piece of equipment in a home theater setup. Forget Laserdisc and videotape, were told DVD is the ultimate home entertainment format.
At the same time, DVD technology is becoming more available to computer users. Now that Windows 98 is shipping, this technology should become even more popular. Windows 98 includes a DVD Player application in addition to the standard CD Player and Media Player programs. For computer users, DVD is often described as better than CD-ROM, CD-Recordable and CD-Rewritable. Ultimately, this is probably true. But is it true today?
Given all the "buzz" about DVD, we thought it was about time Government Video took a look at this technology in an attempt to move beyond the hype and figure out what DVD is, what it isnt, and whether you should start thinking about it for your facility.
Comparing CDs and DVDs
Just as there are different types of CD formats, there are also a number of DVD formats. The nice thing is that CDs and DVDs are the same size, so all DVD hardware being produced today is also capable of reading CDs. That's good news if you only have room in your computer for one kind of drive.
DVD discs hold substantially more data than CD-ROMs for several reasons. The use of smaller "pits" and closer-spaced tracks increases a DVD disc's total storage capacity by more than 700% compared to a traditional CD-ROM. Data can also be stored on both sides of a DVD disc and in two distinct recording layers on each side of the disc. A DVD disc will hold up to 17 GigaBytes (GB) of data, more than 26 times the capacity of a standard CD-ROM.
DVD drives are capable of reading standard CD-ROMs, but the reverse is not true. As the price of DVD drives goes down and the availability goes up, more and more computer manufacturers will be installing them instead of CD-ROM drives. Today, the number of computers that come with DVD capability is fairly small, but it seems to be growing with every new catalog we receive.
Advantages of DVD
Aside from the obvious advantage of higher capacity, DVD-Video offers a few other advantages as well. This is a format that has been designed from the ground up to deal with high quality audio and video as well as a high level of interactivity.
DVD-Video provides CCIR-601 quality images. It is capable of recording and playing back 720x480 resolution video at 30 frames per second. Both MPEG-1 and MPEG-2 compression is supported at either NTSC or PAL frame rates. In addition, both 4:3 and 16:9 aspect ratios are available with support for Normal, Pan/Scan and Letterbox display. Finally, closed captioning is also supported.
On the audio side, Linear PCM audio is available at 48 and 96 KHz with up to 24 bits per sample. There can be up to 8 discrete audio channels and the maximum transfer rate supported is over 6 Megabits (Mb) per second. Dolby AC-3 audio is supported by all NTSC players and is optional for PAL players. This is a 48 KHz compressed format with support for 5.1 Surround Sound and a maximum transfer rate of 448 Kilobits (Kb) per second. Finally, MPEG-2 Audio is supported by all PAL players and is optional for NTSC players. This is also a 48 KHz compressed format and supports 7.1 Surround Sound with a maximum transfer rate of 640 Kb per second.
DVD-Video provides a higher level of interactivity than either Laserdisc or Video-CD formats. Multiple video angles are supported as long as they are the same length and there is support for multiple story lines and user controlled content viewing. A full set of navigation commands is available to move throughout a disc quickly and easily.
DVD in the Military
The advantages listed above led at least two branches of the United States Military to experiment with DVD as an alternative to CD-ROM and Laserdisc training programs. In both cases, old Laserdisc programs were repurposed and converted to the DVD format.
The first program deals with medical training for chemical warfare triage. It runs a trainee through a series of video scenarios and the trainee must look at the video for clues to help determine if a chemical attack has occurred, the severity of injuries, and the proper way to respond. There are six scenarios in this program with four patients in each. The program allows the trainee to perform an examination on a patient and provides information and choices on the steps necessary for decontamination. At the end, a score is determined based on the decisions made by the trainee.
The other program is an ethics training course where officers are subjected to six different scenarios that involve ethical situations. Each scenario contains eight video clips providing information about different aspects of the situation. This program was also converted from Laserdisc and contains over 35 minutes of high quality MPEG-2 format video and audio.
In both of these situations, the military was trying to determine exactly how viable it is to invest in DVD at this time. Although both projects were successful, the problems that were encountered indicate that it may be a little too early to jump on the DVD bandwagon.
Not Quite Ready for Prime Time
Every new technology can be expected to have a few bugs, and DVD today is no exception. The most frustrating part of the two projects above was the consistency, or rather the inconsistency, of the DVD-ROM drives available for use in the systems. Discs that could be played on one company's drives couldn't necessarily be played on those from another company. In some cases, this problem was even present on different drives from a single company. Just as Compaq computer builds machines with either Intel Pentiums or AMD K-6 processors, DVD-ROM drives from one manufacturer might use parts from different sources at different times.
Late last year, Intel and the Software Publishers Association held a DVD-ROM Compatibility and Test event whose purpose was to provide a forum for testing DVD titles and systems under development. Of the 80 titles tested on 25 DVD-ROM-equipped computer systems, more than 66% failed to work properly on at least one of in most cases several of the DVD-ROM-enabled PCs. It should be noted that all of the titles tested were still under development and that all of the DVD-ROM systems were either beta or pre-production models. However, the results are still discouraging.
DVD also needs to progress with respect to the tools that can be used to produce finished programs. For the military projects, very specialized equipment was used and some custom software was written. Video compression was accomplished using a Minerva (San Jose, CA) Compressionist 250 MPEG-2 Encoder. This Mac-based product uses multiple-pass encoding to insure the best results possible. Dolby AC-3 Audio compression was performed using Mac-based Sonic Studio systems from Sonic Solutions (Novato, CA). Authoring was accomplished using Daikin (Novato, CA) Scenarist running on Windows NT machines. The total investment in equipment to develop the projects was over $100,000.
Using these tools, the DVD-ROMs were designed and then sent out to a replication house to be burned. Emulation software was used to test the programs, but even that software is not fully developed. Since there are no affordable DVD recording devices that can be installed on a computer, outside companies are the only resources to create the actual discs. Sometimes, the result doesn't work and another pass must be made.
Many of the more popular authoring programs, like Director and IconAuthor, are also incompatible with DVD today. With the release of Windows 98, it's very likely that support for DVD-ROM creation will be built into these packages and others in the near future.
It's very easy to get excited about new technologies. Unfortunately, it's usually hard to get them to work when they are first developed. DVD-Video is everywhere and it works. DVD-ROM has a lot of advantages over CD-ROM, but more work needs to be done on the hardware to play DVD-ROM and the tools to create it. You can bet we'll be watching this technology closely. When it's ready, we'll let you know.
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Ralph LaBarge is an independent consultant specializing in the creation of DVD-ROM applications and the Chairman of the Software Publishing Association DVD-ROM Interactive Media Format Technical Working Group. He can be reached by phone at 410-721-9460.
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