Irene Koo

#25300906

Date: Mar 10, 1998

Table 1. Digital Television Standard’s Video Compression Formats

In Table 1., the "# of Active Lines" refers to the number of active lines in a picture; the "# of Pixel per Active Line" refers to the number of pixel in an active line; "Aspect Ratio" refers to the picture’s aspect ratio; "Picture Rate" refers to the number of frames or fields per second. In the values for picture rate, "P" refers to progressive scanning and "I" refers to interlaced scanning. Dual picture rates such as "60.00 Hz", "59.94 Hz", "30.00 Hz", "29.97 Hz", "24.00 Hz", and "23.98 Hz" are allowed.

The ATSC Digital Television Standard also specifies a throughput of 19.28 Mbps in a 6 MHz terrestrial channel and 38.57 Mbps in a 6 MHz cable television channel.

The current DVD standard supports both MPEG-1 and MPEG-2 in its video standard. It also supports MPEG-1 stereo, MPEG-2 5.1 and 7.1 surround, Dolby Digital 5.1 surround, Dolby stereo Prologic, and Linear PCM in its audio standard [FOG96][HUG96][VIC96]. DVD conforms to a subset of MPEG-2 video specifications [ISO13818-2], namely the MPEG-2 MP@ML (Main Profile @ Main Level) parameter set. The MPEG-2 Main Profile supports three types of frames for prediction: I-frames, P-frames, and B-frames. Its chroma format is designated to be 4:2:0 within a frame. The Main profile does not support any form of scalabilities. The MPEG-2 Main Level includes resolutions up to 720 pixel per line and 576 lines per frame, and it includes frame rates up to 30 frames per second. The compressed data rate is limited to no more than 15 Mbps [HPN97]. Although DVD complies with MPEG-2 MP@ML, its video data specifications are more restrictive than that of MPEG-2 MP@ML. Table 2. describes the additional restrictions DVD added to the MPEG-2 MP@ML parameter sets [FOG96] [VIC96].

 Table 2. Additional DVD Specifications to the MPEG-2 MP@ML parameter sets

 Table 3. Current DVD Audio Specifications (1)

Table 4. Current DVD Audio Specifications (2)

The DVD standard also specifies a 10.08 maximum program_mux_rate.

Manufacturers have been making progress in achieving HD-DVD. Sony Corporation announced in May 1997 that it had developed technology to produce recordable optical discs able to store 12 gigabytes of information on one side of an optical disc [CNET97]. Matsushita Electric Industrial co., Ltd. of Osaka, Japan announced on June 9, 1997 that it had developed a 15-milliwatt blue laser using a waveguide for second harmonic generation (SHG) of the original laser beam coming out of an infrared semiconductor laser. This SHG blue laser will be able to read and record 15 gigabytes of data on one-side of a phase change optical disc [CNET97] [CMP97a] [NAT97]. In late 1997, Fujitsu Laboratories Ltd. announced that it had succeeded in fabricating a blue laser that allows optical discs to store about 13 gigabytes of MPEG-2 high-level compressed video [LAM97]. In February 1997, The Research and Development Center at Toshiba Corporation demonstrated an experimentally fabricated high-definition DVD system that can store and play theater-quality movies stored in a 12 cm optical disc with a 15 gigabyte capacity [TOS97] [CMP97b]. Recently, there were "talks" about using double-speed red-laser DVD instead of blue-laser DVD to achieve HD-DVD.

DVD has been promoted as a "must" equipment for home theatre entertainment systems and has been achieving great success in sales. The sales of DVD video players in the United States have been averaging over 34,000 units per month since August 1997 [TWICE97]. Public are enjoying DVD because it gives much higher picture and sound quality than those provided by ordinary television systems and Laserdisc systems. DVD supports a widescreen (16:9) movie format, which gives fuller descriptions of scenes. It also supports up to 8 different digital audio tracks, different camera angles, and interactivity features. HDTV-DVD can further increase the values of home theater movie viewing. For example, HDTV-DVD highlights a sense of reality because large images can be viewed without annoying artifacts that appear on older standards [WEB]. The 16:9 aspect ratio allows viewing of an HDTV image at a distance three times the height of the picture, thus generating a 30 degree field of vision that excites the peripheral portion of the human visual system. The excitation of both the central portion of the visual system and the peripheral gives a greater interpretation or illusion of reality experienced by the viewer [WEB]. The increase in frame rate combined with progressive scanning can remove most of the annoying flickering present in current television systems.

Unfortunately, the price for having these increased values in viewing may not be low. As mentioned above, current DVD video players do not support HDTV playback. Thus, new HDTV-DVD players are required. In order to take advantage of the increased aspect ratio, the higher resolutions, the higher frame rates, as well as progressive scanning supported by HDTV, new display devices are also necessary. Initial price estimates on new large widescreen television systems range from $6000-$35000 [WEB] [TEC98] [LEV97]. Manufacturers are also putting their eyes on the set-top-box market. Viewers, who are not willing to spend a large sum of money on a new high-end television system, can instead purchase a set-top box. The set-top box will down-convert HDTV signals to signals compatible to current standard television systems. New low-end television systems may also be set-top-box ready.

Two technologies are gaining much of the focus of the television broadcast industry in North America: high definition TV and the real-time streaming of video and audio via the Internet [KM97]. Kelley and Menard suggested that broadcasters are enthusiastic about Internet video streaming products because they offer interactivity and provide a one-to-one relationship with the viewer and their global audience. According to A. C. Nielsen, 49 percent of web users say accessing news-related information is the most important reason to go online [KM97]. Video/ audio news via the Internet attract many web users because content providers/ broadcasters provide much more depth to online news than traditional television broadcast news. For example, CBC Newsworld Online not only provides news updates throughout the day during any day of the year, but also provides highlights and updates on special events such as the recent XVIIIth Winter Olympics held in Nagano, Japan. In addition to highlights and updates, CBC also offers background information, pointers to related web sites, and additional information which are not available to traditional broadcast audience. The most important aspect of online information programming is the users’ ability to control the information they acquire. That is, online users can choose which segments of news they watch and when they watch. Unfortunately, the video and audio quality offered by current Internet streaming products are very low. To make the matter worse, viewings are typically done on a 15" or 17" monitors. Now imagine what it would be like to view such programming on a HDTV display device with a video resolution up to 1920x1080 and with 5.1 discrete audio channels. Furthermore, one still have complete control over the segments of news he/ she watches and still get all the in-depth information related to the news he /she watches. Such viewing experience can be offered by Internet HDTV. Another advantage of Internet HDTV is that since HDTV devices have a high (16:9) aspect ratio, multiple programs or a program with its related information can be displayed side-by-side instead of overlapping one on top of the others.

The idea of hybrid HD-DVD is evolved from hybrid CD, which basically is a conventional CD-ROM with detail data on topics such as a database, a bibliography, an instruction manual, a shopping catalogue, or an encyclopaedia, allied with online access [QUI97]. The problem of these discs is that their content becomes out-of-date very quickly. Until recently, the only solution to this problem is frequent redistribution of the discs with new updates. Hybrid CD solves this problem by offering users built-in access to updated content online. Extending the Hybrid CD idea to HD-DVD, a typical hybrid HD-DVD disc would contain enriched media content with very high visual quality, superb surround sound, and real-time information from Internet sources [FRE96]. Advertisement can also be a type of real-time information being sent across the Internet. Picture a situation where the content of a HD-DVD disc contained a full-featured 133-minute movie with 5.1 discrete channels surround sound. However, unlike regular HD-DVD movie discs that customers purchase at local video stores, advertisement such as those being presented before a movie showing at theatres, could be downloaded and shown to the viewers. Movie producers/distributors could then sell these advertisement time to different companies, charging different rates according to how long the movie has been out. Of course, the price the customers paid for purchasing the disc should be less than that of a regular HDTV-DVD disc. This way, everybody would benefit.

Another possible candidate for hybrid HD-DVD application is multiplayer, interactive video game. High resolution background and activity updates are two key issues in realistic games [VAR97]. HD-DVD, with its high storage capacity, high quality video and surround sound offering, as well as interactive capability, can provide a rich environment with complex video, sound, and imagery similar to a TV movie to gamers. With a connection to the Internet, the possibility of multiple-players, supplemental data, and enhancements becomes a reality.

High data rate communication channels are required for broadcasting HDTV signals. To provide interactivity for HDTV, Internet-HDTV, and Hybrid HD-DVD, bi-directional communication channels are needed for uploading commands and downloading contents. With a newly awarded second 6 MHz channel, broadcasters are finally able to provide HDTV programming over this second 6 MHz channel. However, the FCC has not been able to settle questions such as "how many hours of HDTV programming must be provided by broadcasters over the newly awarded channels?" "Can several SDTV programs instead of a single HDTV program be broadcast over the new channel?" "Can broadcasters use the new channel to provide other interactive services?", which will definitely affected the acceptance of HDTV as well as the way broadcasters manage their business. The biggest challenges for broadcasters right now are to come up with a large sum of money to purchase and install broadcasting equipment for HDTV transmission and to derive a plan to turn the HDTV transmission business a profitable one. It is estimated that the cost of installing new broadcasting equipment for HDTV transmission ranges from $800,000 to about $3,000,000 for local television stations to pass through a network digital television feed, without originating their own HDTV programming [WEB] [LEV97]. The cost for network broadcasters can easily go up the tens of millions. In order for broadcasters to recover their millions dollar investment, they must make the most out of the newly awarded 6 MHz channel. Broadcasters believe that just using the new channel to broadcast HDTV programs will not generate the profit they need. Broadcasters will most likely carry major sport events, high profile movies, and some special events in HDTV. Beyond that, they will use the channel to provide "standard definition" TV as well as interactive services.

Although the FCC has not mandated cable operators to provide digital transmission, cable companies have to ability to provide HDTV programming. The modulation scheme 16-VSB (Vestigial Side Band) can give 38.57 Mbps of data in a 6 MHz cable channel [ATSC95]. That is, two full HDTV signals can be transmitted in a single cable channel. However, the cable distribution network was initially designed for analogue, one-way communication from a head end to individual subscriber [POH97]. Cable companies must modify their system in order to support digital transmissions as well as bi-directional communications. Today, cable companies are busy purchasing digital equipment and replacing their existing coaxial cables with fiber optic cables. They are also migrating their system from the traditional tree-and-branch architecture to a network such as Hybrid Fiber Coax (HFC) that uses both fiber and coax. Using splitband systems, HFC can support bi-directional communication. As with terrestrial broadcasters, cable companies are facing a high cost for installing digital equipment and overhauling their coaxial cable infrastructure. They also wonder if subscribers are willing to pay for the audio-visual improvement provided by HDTV. How cable companies can recover their investment in digital transmission and make HDTV transmission a profitable business is remain to be seen.

Digital Satellite Broadcast (DSB) is already a digital broadcast technology. Therefore, the setup cost for providing HDTV transmission for direct broadcast satellite companies is not as high as that of terrestrial and cable broadcast companies. However, due to the high bandwidth requirement for HDTV, direct broadcast satellite companies need to reduce the number of channels offered to provide HDTV programming. Furthermore, DSB is a great one-way communication technology to the customers; it lacks two-way communication capability. Thus, DSB companies are not planning to offer HDTV transmission in the near future.

HDTV and DVD do give many hypes and hopes to the future of our society: Television manufacturers are eager and excited that HDTV-related products will give them a renew cycle of profit making. Broadcasters and cable companies are betting high on HDTV, hoping it will give them a chance to gain a large piece of the market. The computer industry is hoping applications such as HD-DVD will lead them invade the television industry. How successful each of these industries will become is remain to be seen. One thing for sure is that videophiles will be extremely excited about the times ahead.