New technology for digital TV is shaking up the market. Nick Flaherty reports.

A new generation of technology is emerging for broadcasting digital TV, but there is a split in the standards and a separate split in the way the technology can be licensed. The latest standard compression technology, MPEG4 part10, also called H.264 and the advanced video codec (AVC) is an open, global standard that offers twice the compression of today's MPEG2 technology. This will allow twice as many digital TV channels in the existing bandwidth on satellite or cable TV networks, or to allow one or even two high definition TV channels.
"In general for high definition it's just at the point where starts to make commercial sense, driven by the reducing cost of HD flat screens and H.264," said Ken McCann, a director of Zetacast, a UK-based independent technology consultancy specialising in digital TV.
But there is competition between technologies. Microsoft has been gaining ground with its WindowsMedia9 compression technology which offers similar compression, and several telecoms operators have signed up to use the technology to run video over phone lines using high speed DSL modems and the IP internet protocols.
On the licensing side, there are now two groups looking to license the patents behind AVC. This is critical as severe delays in the licensing terms plus having to pay a fee for each minute of material that was broadcast restricted the take-up of the previous generation technology, MPEG4 part 2.
Now Via Licensing, the licensing subsidiary of audio experts Dolby Labs, has proposed a flat fee of 25c instead of the per use approach and has signed up 9 patent holders in the last two months.
"We have eliminated the use fees altogether," said Ramzi Haidamus, general manager of Via Licensing. It has persuaded ten companies, including IBM, Apple and its parent, Dolby Labs, to join, as well as the Fraunhofer Institute, LSI Logic, Motorola and RealNetworks, and even includes Microsoft, which has the competing Windows Media 9 technology. What Via doesn't have are key patent holders such as Sony and Philips. In the meantime the existing licensing body, MPEG-LA, had meetings with patent holders in September and October but has not yet released its terms for licensing AVC.
"We are committed to reaching agreement on joint license terms during the fourth quarter 2003 and we are getting close and something may be ready very soon," said Larry Horn, president of MPEG-LA.
Unless one group gains the upper hand, users will have to go to both groups for a license which will increase the cost, and user groups are worried.
"I am eagerly awaiting MPEG LA announcements to see what their terms look like," said Rob Koennen, president of the MPEG Industry forum. "Then I hope that some licensors understand that the two agents need to be 'encouraged' to work together so that we can have essentially a single licensing scheme."
If the problems are not sorted out, AVC is in danger of losing out to Microsoft's WM9. In a bid to make WM9 more open, Microsoft has published the key specifications of the format, but not of the underlying technology. Microsoft points to its single point of licensing as one of its key advantages. At the same time WM9 is gaining significant ground after a deal with leading encoder maker Harmonic, following last year's deal with the other leading encoder maker, Tandberg TV.
AVC and WM9 give two to three times the compression of today's MPEG2 systems and is vital for adding more channels to existing cable, satellite or terrestrial digital TV, to run good quality TV over phone lines for video on demand or for high definition TV broadcasts and DVD disks. Other AVC patent holders in discussion with the two groups include Columbia University, France Telecom, Fujitsu, Matsushita, Mitsubishi, Nokia, Philips, Samsung, Sharp, Sony, Thomson, Toshiba, and JVC.
Despite the licensing issues, chip vendors are developing silicon for encoders. LSI Logic has developed the VLE400 real time H.264 encoder which runs on three field programmable devices and a dual Pentium PC, as the system also includes detailed analysis of each block that is encoded. This is likely to form the heart of the E6 chip, although LSI would not comment on when that chip would be ready. LSI's E4 chip has been the mainstay of the MPEG2 encoder market, used by Harmonic, Tandberg, Scopus, Motorola and Optibase. The prototype system allows encoder makers to start developing their own software so that it will be ready when he encoder chip is delivered.

shorter codes

LSI Logic has filed several patents on the CABAC - content adaptive binary arithmetic coding - that assigns shorter codes to elements of an image that occur more regularly, allowing tighter compression of the image.
The prototype system is being used by Modulus and video on demand server supplier Seachange. But taking an alternative approach is Texas Instruments. A leader in digital signal processing, TI has previously not focussed on the broadcast industry. But it has won slots for its C6414 DSP processor with iVAST and Tandberg, promoting the flexibility of working in software.
"Our real time broadcast quality audio video encoder uses TI DSPs for part of its core video and audio coding," said Charles Cartwright, business development manager for Advanced Coding at Tandberg.
With the latest silicon manufacturing technology and some additional hardware blocks to accelerate key algorithms, the chip can be made fast enough to handle broadcast encoding data rates. The current generation is running at 600MHz, but TI has already produced samples of the chip running at over 1GHz. This will allow the encode makers to produce higher performance equipment with the same software code.
The other key advantage is that the same hardware can be used for the competing Microsoft Windows Media 9 compression technology which is very different in structure to H.264 but uses the same basic blocks. Using the 720MHz C6414 allowed Tandberg to produce a WM9 encoder last year and a H.264 this year once the standard was agreed. It also means that changes and developments, particularly in WM9, can be incorporated easily.
The iVAST encoder uses the 6416 with 256Mbutes of memory in a 1U rack and handles the existing MPEG4 standard up to D1 resolution, and is ready for an H.264 upgrade, says the company.
Envivio is also using a TI part, the DM642 digital media processor, for its real-time 4Caster MPEG-4/H.264 encoder. Based on the same core as the other DSP processor, the 4caster gives a 50to 60percent improvement in bit rate reduction of MPEG2 systems.
"Since the TI DM642 is fully programmable and contains integrated multimedia and communication peripherals, we have been able to simplify the design and produce the most effective real-time H.264 encoding system available," said Eric Deniau, Vice President of Engineering at Envivio.
But it not just broadcast applications where H.264 encoders will be needed. There are at least two start up companies working on silicon for H.264 encoders to go into set top boxes and personal video recorders (DVR).
Sand Video is developing an H.264 codec that could be used in PVR systems to dramatically increase the amount of video that could be stored on a hard dick drive, particularly when HD is needed.
"AVC/H.264 can substantially reduce costs and improve performance in standalone and set-top box PVR/DVRs and DVD recorders," said Don Shulsinger, Executive Vice President Sales and Marketing at Sand Video. "Hard disk drives are a substantial cost element in these devices and with high definition capabilities becoming more and more prevalent, OEMs must find a way to store this content without adding additional drive capacity and thus significant added cost. Sand Video's AVC/H.264 technology is designed to allow OEMs to easily incorporate these advanced compression capabilities and gain a significant competitive advantage in their respective markets."

High definition decoder core

Sand launched the high definition decoder core, the SV-IP01, in July that supports the AVC standard Main Profile up to and including 720p and 1080i. The core includes support for the complete set of Main Profile AVC tools, including context-based adaptive binary arithmetic coding (CABAC) and Context Adaptive Variable-Length coding (CAVLC).
The codec chip family, the Advantage264, is in development with the launch planned for the first quarter of next year, with the SV-C011 codec and the D011 decoder as the first products.
Another player is Mobilygen, a start-up in San Jose that is developing an H.264 coder and decoder. It has already developed an MPEG2 block that is has been licensing out, but it plans to make an H.264 chip later this year (2004).
Meanwhile companies such as LSI Logic and Texas Instruments are planning to get back into the digital TV market with H.264. TI is the world's leading supplier of digital signal processing chips. It dominates the market for GSM standard cellular phones with its OMAP platform that uses ARM co-processor, and has a strong heritage in high performance signal processing, especially real time video. It is also strong in DSL with chipsets for the central office and for DSL modems, which gives it a strong entry in IPTV. TI has been in the digital TV market through its ARM-based AV7000 ASSP, which is used by TechnoTrend for a cable TV box, but that part was not a major success and has not been developed.
But TI is now looking at getting back into the DTV market. This is partly as a result of the developing process technologies that are driving the performance of the DSPs up and the cost down. The C6x VLIW engine has traditionally been too large for mainstream consumer applications, but TI is planning a $5 version of the core and that now lends itself to a single chip integration with a CPU core, following the same strategy as OMAP in the GSM arena.
"We believe was have an interesting window in the market," said Jean-Marc Charpentier, European DSP catalogue business development manager. "There is big turmoil in the market right now with satellite, cable and terrestrial digital TV. It is interesting that everyone is pushing their own solutions and we are one of the only providers to offer an elegant, fully programmable solution. We are gaining traction with VoD in Taiwan, with DSL with the 6415 and with DM642," he said.
Derivatives of the DM640 will fall to under $20 in 10K volumes in 0.13mm with the four channel DM642 at $40, or $10 per channel. These are being targeted at high end boxes for VoD and PVR that are shipping in 50 to 100000 unit volumes, he says.