USDTV navigates unchartered waters with Blackfin

USDTV showed off its new MPEG-4 AVC H.264 upgrade, based on Analog Devices' Blackfin processor, in the DTV Hot Spot at NAB2006.">

USDTV demonstrated its new MPEG-4 AVC H.264 upgrade to its service last April at the DTV Hot Spot at NAB2006 in Las Vegas.

Bringing more SD channels and premium services to customers, the upgrade relies on a palm-sized peripheral that plugs into the set-top-boxes of existing USDTV customers via a USB connection. At the heart of that peripheral is the Analog Devices Blackfin processor, which transcodes the incoming MPEG-4 stream to an MPEG-2 stream that’s handed off to the USDTV set-top box.

While USDTV does not offer HD channels, its wireless delivery of multiple SD channels augments the high-definition channels of its broadcast partners by offering them a way to monetize their pooled digital multicast bandwidth and make over-the-air television delivery more competitive with cable television from the point-of-view of selection and price.

Seen through that prism, USDTV’s demonstration of H.264 support and greater SD channel selection is particularly relevant to the discussion of high-definition broadcast.

"HD Technology Update" caught up with Garry Paxinos, senior vice president/chief technologist, at USDTV and Chuck Goehringer, Blackfin marketing and business development manager, at Analog Devices, to learn more about the implementation.

HD Technology Update: USDTV announced and demonstrated at NAB2006 an MPEG-4 H.264 implementation of its service allowing it to offer more channels in the same bandwidth. Where does the Analog Devices Blackfin processor fit?

GarryPaxinos: The Blackfin is being used to retrofit or upgrade our existing set-top box, which is based on the ATI Xilleon. The Xilleon only supports MPEG-2 and by attaching a Blackfin to it through a USB port we are now able to transcode it into MPEG-2 so the set-top box could display it. Basically, we are using it to support existing customers with our legacy set top until we can get the Sigma Design set top box to market.

HDTU: Once the Blackfin is used, will you move to MPEG-4 H.264?

GP: That is correct.

HDTU: How many more channels will H.264 allow you to offer in the same bandwidth?

GP: It allows us to increase the number of channels in the same amount of bandwidth as well as offer additional services. We haven’t yet announced the actual split between new channels versus new services.

HDTU: What are some of the new services you have in mind?

GP: We’ve talked about movie services in one of our press releases.

HDTU: Is there an easy upgrade path to accommodate more aggressive compression schemes as they come along? In other words, in the future as more aggressive compression algorithms come along will a new hardware roll out be required, or will the Blackfin’s processing power be sufficient?

GP: I think both the Sigma (the Sigma Design processor-based next generation set-top box) and the Blackfin will be effective. With the Blackfin and with the Sigma chip and even with our Xilleon-based platform, we do have a mechanism to download new software updates over the air —basically a field upgrade without a truck roll. If we do have a new algorithm that can work within a Sigma or Blackfin, we can then field upgrade it over the air.

HDTU: Analog Devices emphasizes processing performance and processing efficiency as two key benefits of Blackfin. Did that play into your decision to base your upgrade on the processor?

GP: Absolutely.

HDTU: Why is that important and were there any other factors?

GP: The power efficiency is important because the device is connected solely to the set- top box and draws power off the USB port. So having a power efficient design is obviously important because of the use of USB 1.1. Another huge factor was the low risk doing a design based on the Blackfin while still having the processing power to do full transcoding of AVC H.264 stream.

HDTU: How many customers have to be upgraded?

GP: I don’t believe we’ve announced that, but enough to make it worthwhile to go through the engineering effort to do it.

HDTU: Did USDTV engineer this Blackfin-based MPEG-4 upgrade itself, or did it have help?

GP: We did work with a company called Opgate that did have the AVC decoder and MPEG-2 encoder software, and we also worked with another company to do the production design and manufacturing.

HDTU: So Blackfin was designed to support these sorts of applications?

Chuck Goehringer: Yes, actually. One of the exciting things about Blackfin is that it is a fully programmable solution. It does not make any assumptions. So we have a family of processor products that are used in a number of multimedia applications. The exciting thing about what USDTV did was that by taking advantage of the high performance, low cost, low power of the Blackfin, they were able to cost effectively move to these advanced video compression standards that are low risk and have the ability to deal with these new technologies very, very quickly. I believe USDTV is a leader in moving to these new standards, and we like to think at Analog Devices that we had a big part of that with our technology.

HDTU: What other Blackfin implementations are likely for the future?

CG: To date, we’ve announced a really large spectrum of applications. We’ve had some announcements in mobile TV, which obviously have an important audio/visual component. We’ve made announcements in things like next-generation videophones and video conferencing with companies like Be Here. We’ve made announcements in video surveillance applications and PVRs. We also have quite a few things going on in automotive, telematics, and entertainment. There really is a whole host of applications as audio and video become more pervasive.

What really is exciting in the whole proliferation of audio/video multimedia technology to a host of devices and Blackfin’s ability to work with these advanced video codec standards is having an exciting place in those markets.

HDTU: Will the upgrade to H.264 include a mix of HD offerings?

GP: At this point the HD is limited purely to the local broadcaster. USDTV is more value-oriented and more a standard definition service. In addition, we are using a USB 1.1 interface so we are somewhat constrained by what we can push through that connector.

HDTU: How important is the USDTV implementation of Blackfin to Analog Devices?

CG: Our goal is to lead from a performance capability to enable innovative companies like USDTV, who are trying to take advantage of these advanced compression standards, to deliver real value to their customers. We are very excited about what USDTV was able to accomplish, and we are going to try to keep delivering on the promise of lowering cost and increasing the capability so that in the future, there will be more demand from customers to do things like this, and we want to be at the forefront of that.

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