Electronic Design

What's Hot Today: Home Entertainment

Today's Home-Theater Systems Lack Only A Popcorn Maker

The pleasure of going to the movies or a concert is the sensory experience brought on by massive screens and booming sound systems. Thanks to the confluence of many technologies, you can recreate the ambience of the movie theater or concert hall at home—and even enjoy it on the road.

On another front, video games have undergone major enhancements. Supercomputer-like graphics capabilities, networked communications, and even force-feedback joysticks, mice, and other controls put gamers right in the middle of the action.

Advances in digital technology are making a wide variety of entertainment products possible and affordable by implementing high-performance control and signal-processing functions for very few dollars. Whether it's audio or video, the use of DSP algorithms and chips, along with intellectual property, has opened many opportunities to improve audio and video quality, as well as add special effects.

Recreating the atmosphere of a concert hall or a nightclub, the visual and audio effects of a large-screen movie, or the realism of the latest 3D game depends on many technologies, not just continual improvements in digital ICs. For instance, the ever-popular wall-size video displays are seeing significant advances in both high- and standard-definition direct-view and projection video systems. As for handheld entertainment, major improvements in small-area displays will create greater realism in gaming devices as well as higher-resolution video playback.

Higher-quality, more immersive audio systems are also coming. The Dolby 5.1 and THX sound systems used in movie houses are already appearing in many home theaters. Yet as screens get bigger, audio systems must get better. The current 5.1-channel sound systems are ceding to 7.1 channels, adding another set of rear-channel speakers to enrich that surroundsound feel. Over the next few years, mainstream systems with even more sound channels and features will help you match the sound system to the room.

For those who really want the theater experience at home, large-area plasma flat panels now come in sizes once thought impossible. At the latest Consumer Electronics Show, LG Electronics and Samsung Electronics demonstrated prototype panels with diagonals of 76 in. and 80 in., respectively. If you have to ask the price, though, you probably can't afford them. (Estimated retail pricing will be between $20,000 and $30,000.) And as you might expect, efforts are under way to create even bigger plasma screens.

LCD-based flat-panel displays are also expanding, with 55-in. panels now available from LG Electronics, Sharp, and a few others. Emerging as an alternative for small-area displays, organic-LED (OLED) displays show lots of promise as a direct-view technology for large-area flat panels. But a number of technology hurdles still must be overcome to make large OLED panels manufacturable at a reasonable cost.

Projection systems eliminate the need for the big sheets of heavy vacuum glass required by plasma panels, yet they still deliver large, bright images. Though not new, HDTV projection systems have been hampered somewhat by their bulkiness. Some upcoming projection systems, however, free up some floor space while providing larger screens, better resolution, higher brightness, and lower cost.

The older projection systems based on high-temperature polysilicon light valves are giving way to systems based on digitally controlled micromirror technology. For example, there's the digital light processor (DLP) from Texas Instruments. And, Mitsubishi and Intel favor an all-digital approach that deposits a liquid-crystal matrix on top of a silicon chip (LCoS).

Many companies producing projection systems are adopting the digital micromirror display (DMD), since it has a simple image path that allows for very slim system designs. One forthcoming system, the ScreenPlay 61 developed by InFocus, is just 6.85 in. deep—thin enough to hang on a wall. It offers a 61-in. diagonal and native HD resolution of 1280 by 720 pixels and includes a built-in HD tuner and browser (Fig. 1). Also coming is a 61-in., sub-7-in. deep system from RCA as part of the Scenium HDTV family, which happens to be based on the TI DLP as well.

For those of you with really big rooms, get ready for the largest-screen HDTV projection system yet developed. The Alpha WL82913, in final development at Mitsubishi Electric's Digital Television Division, will have a screen diagonal of 82 in. and use three LCoS chips (one for each primary color) to deliver a 2-Mpixel image with a resolution of 1920 by 1080 pixels (Fig. 2a).

Projection systems based on LCoS imagers show a great deal of promise, according to Intel. The company feels that the other technologies can't increase their resolution as easily, so certain tradeoffs may be required to achieve resolutions of more than 1280 by 720 pixels. LCoS technology under development at Intel leverages standard silicon processing and scaling opportunities, enabling higher pixel counts on the same chip area without compromising picture quality or manufacturability (Fig. 2b).

If you don't want a box sitting on the floor or a big panel hanging on the wall, try direct projection systems. They're similar to the desktop projectors now replacing the ubiquitous overhead projector. But the software and display subsystem is tuned for home use and to deliver multimedia content rather than static PowerPoint slides or still images. These projectors can be ceiling-mounted to project onto a wall or screen or easily moved from room to room. Many also incorporate wireless network interfaces so video can be streamed to the system, eliminating extra cables.

The digital video disk has revolutionized the digital entertainment industry. With HD video coming on strong, changes to the basic DVD will arrive as well. The 6-Gbyte capacity of today's DVD must increase almost tenfold to hold a full-length HD movie. Soon, standard DVD disks will lead to enhanced disks, possibly based on the Blu-Ray blue laser standard, which will push the storage capacity to 50 Gbytes on a single disk (www.blu-raydisc-official.org/index.html).

Convenience is key when watching TV or recording a program, either with a personal video recorder (PVR) or a video tape recorder (VTR). Now, affordable DVD recorder systems are entering the mix as an option. Typical of these systems is the Philips DVDR1000 (Fig. 3). It can record up to four hours of video onto rewritable DVDs, copy camcorder tapes onto DVDs, provide direct access to recordings with no rewinding or fast forwarding, and play DVDs and audio CDs (R and RW). Consequently, the basic DVD player is moving aside for a full DVD player-recorder that, in another year or two, promises to replace the video tape recorder.

The PVR/digital video recorder, as popularized by TiVo and other companies, is evolving from a single-function device to a multifunction unit. It now includes a hard-disk drive to record TV programs for time-shifting and live pause capabilities and a DVD player or player/recorder so you can watch a DVD while recording a TV broadcast.

Most of us don't really envision our family room situated with a PC that also contains the AV center, because PCs tend to be noisy and often require a separate screen and lots of cables. But the PC is getting a radical makeover to more readily blend into the entertainment complex. Intel, Microsoft, and many other companies have defined a new class of media-centric PC that's optimized for viewing and creating video and audio content. As opposed to a standard PC, a media-center PC usually includes a remote control so users can access and play the various media files without a keyboard. Also featured are a TV tuner, an advanced graphics card, a hardware MPEG encoder, a TV output, a digital audio output, and of course, the Media Center version of Microsoft Windows XP.

Typical of such media PCs is Hewlett-Packard's Media Center m400y (Fig. 4). Configurability is its main attribute. CPU options range from 2.8 to 3.4 GHz, main memory of up to 1 Gbyte of double-data-rate (DDR) DRAMs, and up to 250 Gbytes of hard-disk space. Among the many other options are primary and secondary CD/DVD drives (readers, writers, or combo drives), a multiformat memory card reader, a 5.1-channel sound card, a graphics card with 128 Mbytes of DDR memory, and a TV output.

In addition to systems targeting the multimedia market, another class of PC has evolved to serve the needs of advanced gamers. Exemplifying this genre is the just-released Compaq X system (Fig. 5). It comes packed with 10,000-rpm disk drives for blazing disk access to keep the scenes moving quickly and 256 Mbytes or more of DDR2 DRAM on the highest-performance graphics cards.

If you play a dedicated game system such as the Sony Playstation 2, the Microsoft X-Box, or the Nintendo Game Cube on a TV, the experience is moderately exciting. But play on one of the over 50-in. flat-screen TVs or projection systems, and you're in another world. As 2005 approaches, expect greater detail on the next-generation platforms. More lifelike characters, more realistic scenery, and improved response times will further immerse you in the game.

Instead of a game console, Mitsubishi Electric Research Laboratories is experimenting with a table-like platform called the DiamondTouch. The system, as currently configured, lets people to sit around a touch-sensitive screen to play games or collaborate (Fig. 6).

One of the nastiest jobs in A/V is interconnecting all of the equipment. Cables are everywhere, often intertwined in a big knot, and you're never sure whether the correct component is connected to the right A/V jack. As wireless networking becomes more ubiquitous, it will serve as the backbone that interconnects all A/V equipment at home. In addition, IP addresses will replace jacks.

In the last few years, many companies supported the IEEE-1394 Firewire scheme, and it remains popular on most handheld video cameras. It's also available as an I/O port on many set-top boxes and PC/Macintosh computers. Yet wireless interconnects and USB 2.0 can now provide the connectivity needed from handheld devices to host systems and between host systems. Nothing is resolved at this point, though, as there is no clear winner in the interconnect game. Although existing wireless networking schemes like 802.11a, b, and g were originally designed for data transfers, they can serve at home as media transport schemes. But they carry various overheads that simply aren't necessary there.

Several versions of ultra-wideband (UWB) communications schemes, as defined by the IEEE 802.15.3a working group, are strong contenders for the home network. UWB offers a low-power, low-cost, and low-implementation complexity wireless communications solution. And depending on the application, UWB can trade off bandwidth for distance—data rates can surpass 500 Mbits/s for short distances, while bandwidth can drop to tens of megabits for longer distances. Standards groups expect to finalize one UWB standard by late 2004, which will translate into commercial solutions by late 2005.

With over 120 members, the Multiband OFDM (orthogonal frequency-division multiplexing) Alliance (MBOA) has developed one of two competing UWB approaches. Silicon implementations probably won't start appearing, though, until mid-2005 to late 2005.

The competing specification, based on a direct-sequence scheme, is offered by Motorola (now Freescale Semiconductor) and XtremeSpectrum. Not only are chips available, but the implementation has FCC approval. Therefore, companies can build UWB radios that offer data rates of 114 Mbits/s over a 10-meter distance while consuming less than 200 mW. By next year, Freescale expects to double the data rate for similar distances and quadruple the data rate if the distance is cut to five meters maximum. In 2006, the company expects to crack the 1-Gbit/s transfer rate for five-meter spans. In the future, both Firewire and USB protocols should ride on top of UWB connections, eliminating the cables for those interfaces.

TAGS: Components
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