[Engineering Feature]
Serving Up Multimedia In The Digital Home
Joseph Desposito
ED Online ID #17707
December 13, 2007
Copyright © 2006 Penton Media, Inc., All rights reserved. Printing of this document is for personal use only.
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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 www.electronicdesign.com.
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