Serving Up Multimedia In The Digital Home

Dec. 13, 2007
As multimedia content grows exponentially throughout the home, designers face mounting consumer demands for storing, massaging, and sharing this content. Lots of work has already been done in these areas and standards abound, but naturally

As multimedia content grows exponentially throughout the home, designers face mounting consumer demands for storing, massaging, and sharing this content. Lots of work has already been done in these areas and standards abound, but naturally more is in the pipeline.

For those whose vision is a central repository of digital content on a system such as a media server (see the HP MediaSmart Server shown on the cover), there’s a need to display that content on different kinds of devices and distribute it via wired or wireless networks. But another likely scenario is digital content scattered throughout the home. Users need to access that content from wherever it might reside, on whatever device the user happens to be watching or listening to at the time, whether it’s a PC, settop box, or handheld device.

Recent semiconductor advances related to high-definition content show true industry support for standards. They also give designers the means for building new and better consumer products within the frameworks of these standards.

Interface Insights
As consumers quickly move to HDTV, standards such as High-Definition Multimedia Interface (HDMI) gain more prominence in the home. To give the standard some added teeth, STMicroelectronics recently announced the first HDMI switch, the STDVE003A (Fig. 1).

The switch supports a video data-transfer rate of up to 3.4 Gbits/s. At this speed, full 16-bit color depth—65k colors—is possible, delivering a true high-definition picture. LCD and plasma TV sets stand to benefit, since the switch provides multiple HDMI inputs for external program sources, such as game consoles, set-top boxes, and high-definition DVD players (both Blu-ray and HD-DVD). On top of all this, the switch contains an integrated equalizer that’s designed to overcome signal degradation when using lossy cables or cables greater than 20 meters.

The STDVE003A is an “active digital multiplexer” for high-performance TMDS (transition minimized differential signaling) data transfer. Since it’s configured as a 3:1 switch, TV designers can provide up to three input ports with just one HDMI receiver chip. An internal active block that receives and equalizes the input signal before transmitting it to the next stage maintains and enhances signal integrity.

The speedy data-transfer rate fully complies with the latest HDMI specification, version 1.3. As a contrast, other solutions typically limit color depth to 12 bits (4k colors) due to a lower data-rate capability, even when the original video source—for example, from Blu-ray and HD-DVD players—is 16 bits. A 16-bit source routed through the STDVE003A will result in a brighter, more vibrant 16-bit picture.

At $1.50 in quantities of 100,000, this switch is cost-competitive with similar products. In addition, its compatible package and pin-out make it easy to upgrade current solutions without changing the pc-board layout.

HDMI isn’t the only display standard vying for dominance in the digital home. DisplayPort, the digital display interface standard from the Video Electronics Standards Association (VESA), is also gaining momentum.

Earlier this year, AMD showcased the industry’s first graphics processor with a native DisplayPort interface. Also, Samsung Electronics unveiled a 30-in. LCD flat panel that features DisplayPort’s extremely high 10.8-Gbit/s bandwidth to display a full 2560-by-1600 resolution picture without the use of dual links.

More recently, IDT (Integrated Device Technology) announced that it will focus on developing interface and controller solutions for next-generation digital display devices. The company, which has a working silicon “proof-of-concept” DisplayPort device, is actively partnering with its display customers and companies that want to establish interoperability with the Display Port standard. It is on target to deliver DisplayPortcompatible devices during the first quarter of 2008.

According to Ji Park, VP and general manager of IDT’s Digital Display Operation, “DisplayPort has a number of advantages that make it a clear successor to analog VGA, the current Digital Visual Interface used on TVs and PCs, and the low-voltage differential signaling links used inside notebooks and monitors. Some in the industry also believe that it could serve as a replacement to the High-Definition Multimedia Interface. Regardless of how this all plays out, IDT will continue to support both standards as we believe this strategy will provide the biggest benefit to our customers in the long run.”

Home Networking Anyone?
Networking multimedia content around the home got a boost earlier this year with SMSC’s PCI-based network multimedia co-processor, the LAN9132. It supports Digital Living Network Alliance (DLNA) guidelines.

The co-processor combines support of multiple high-definition audio/video (A/V) streams and software protocol stack management and security through SMSC’s RipStream technology. Thus, the LAN9132’s host of flexible design features addresses the interoperability and content protection challenges of consumer electronic devices. Applications include networkenabled HDTVs, set-top boxes, digital video recorders, home media servers, and wireless multimedia streaming applications.

The LAN9132 caters to the growing number of systems-ona- chip (SoCs) for consumer electronics that require a robust, flexible PCI interface. It’s also well-suited to adapt to future networking interfaces, such as 802.11n. The device itself provides designers with a 32-bit ARM926 core that balances flexibility with offload capabilities for TCP/IP and Universal Plug and Play (UPnP) stacks, as well as Digital Rights Management technologies.

Because the LAN9132 is PCI-based, designers have a broader selection of host interfaces in support of DLNA guidelines. As a result, they can meet in-home networking requirements with higher bandwidth by distributing multiple HD streams simultaneously. Pricing is less than $10 for volume quantities.

Another home networking group, the Multimedia over Coax Alliance (MoCA), gained traction this year. Entropic Communications recently announced the industry’s first MoCA 1.1-enabled chip set, the c.LINK EN2210/EN1010 (Fig. 2). This announcement followed hot on the heels of the news that the MoCA 1.1 chip-set standard was ratified.

With Entropic’s c.LINK chipset, telco, cable, and satellite operators can cost-effectively transform a subscriber’s existing coax cable infrastructure into a 175-Mbit/s home-entertainment networking backbone. With it, users will be able to share digital entertainment content, such as standard-definition TV (SDTV) and HDTV video, music, games, and images.

Back in June, Entropic announced new feature sets for its c.LINK platform, including Parameterized Quality of Service (PQoS), packet aggregation for increased throughput, 16-node support, remote diagnostic capabilities, and preferred network coordination. These features are now part of the MoCA 1.1 specification. Getting these features requires just a software upgrade to the EN2210/1010 chip set.

Meanwhile, the IEEE P1901 Working Group took initial steps toward selecting a single proposal that could form the basis of a standard for broadband powerline communications. The Physical and Medium Access Control (MAC) layers of the proposal incorporate key powerline technology originally introduced by DS2 (Design of Systems on Silicon), such as data rates above 200 Mbits/s, dense multicarrier modulation, time-division multiple-access (TDMA) MAC, and advanced QoS for audio/video applications.

To further bolster powerline networking, DS2 recently announced a technology that will allow next-generation powerline products to operate at a peak data rate of 400 Mbits/s. This will enable the development of new HD-capable multimedia applications, such as multichannel HD IPTV delivery or multi-room personal video recording (PVR). DS2’s 400-Mbit/s technology will be compatible with the company’s existing 200-Mbit/s products, such as the Aitana chip set, ensuring a seamless migration path for existing users and designs. It will also comply with evolving standards. Look for the performance- doubling technology’s full arrival in 2009.

Transcoder Transforms Video
The process of transcoding, which essentially changes multimedia content from one standard format to another, is a very important cog in the wheel of content delivery in the digital home. Transcoding got a big boost recently with the release of a new DaVinci digital media processor from Texas Instruments.

The TMS320DM6467 is a DSP-based SoC specifically tuned for real-time, multiformat, high-definition video transcoding. It’s expected to deliver a tenfold performance improvement over previous-generation processors. Designed to address the HD transcoding challenge in consumer as well as commercial markets, it will likely turn up in IP set-top boxes in the home.

Its multicore design includes an integrated ARM926EJ-S core, C64x+ DSP core, high-definition video/imaging co-processors (HD-VICPs), video data conversion engine, and targeted video port interfaces (Fig. 3). The HD-VICP offers more than 3 GHz of DSP processing power through dedicated accelerators for HD 1080i H.264 high-profile transcoding. Its video data-conversion engine manages video-processing tasks, including downscaling, chroma sampling, and menu overlay functionality.

Less than 300 MHz of the DSP core is used to manage the multiformat video transcoding, leaving the remaining DSP headroom for additional application performance. The device also includes an industry-standard PCI bus and gigabit Ethernet among the connectivity peripherals.

The DM6447 might be used, for example, to transcode a high-definition MPEG2 video stream coming into a set-top box to an H.264 HP@L4 stream in real-time. The transcoded stream could then be sent over a Wi-Fi link for viewing on a handheld device, such as an HP IPAQ PDA.

According to TI, the level of integration and optimization of the DM6467 delivers this performance at one-tenth the cost of previous application systems while maintaining the flexibility needed to address multiple video formats. And with the DM6467 handling the video transcoding, the system will require less power, less expensive DDR2 memory, a reduced flash count, and a smaller FPGA, generating additional bill-ofmaterials savings.

The processor fully exploits TI’s DaVinci development environment, including complete hardware, software, and development tools. Also on tap to speed development is the DM6467 digital video evaluation module (DVEVM), which includes MontaVista Linux, industry-standard and DaVinci application programming interfaces (APIs), the DaVinci Codec Engine, and a host of multimedia codecs for evaluation.

In addition to standard video, imaging, speech, and audio codecs, the system incorporates new transcoders, such as MPEG-2 to H.264. The DaVinci TMS320DM6467 costs $35.95 each in 50,000-unit lots. The DVEVM is scheduled to begin shipping in the first quarter of 2008.

For more information about home-networking standards, see “Digital Home Networks Need Some Discipline” at Drill Deeper 17708 at

About the Author

Joe Desposito | Editor-in-Chief

Joe is Editor-in-Chief of Electronic Design magazine.


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