Digital Video Standards, Production, Processing and Competition
Title: President, Technology Assessors; Director, Rogers Communications Centre; and Associate Dean, Faculty of Communication & Design, Ryerson University.
Broadband Background: Prior to forming his own consulting company, Hearty served as vice president, marketing and sales, for DemoGraFX, which he joined in 2001. Previously, he worked for General Instrument (now Motorola BCS) as director of HDTV development and then as vice president of Canadian sales.
You’re the longstanding chair of the SCTE’s Digital Video Subcommittee(DVS). Technology standards work is an acquired taste, isn’t it? How did you get involved?
Yes, I’ve chaired DVS since April 1996. I began standards work in the early 1980s. At that time, I worked for the Canadian government and was developing methods for subjective quality assessments for video systems. My work was recognized in the ITU (International Telecommunications Union), which then was the CCIR. Well, one thing led to another – more ITU committees, some Canadian committees and, then, the ATSC and the FCC Advisory Committee on Advanced Television Service (HDTV). As part of the FCC-ACATS process, I built and led the Advanced Television Evaluation Laboratory, which carried out all of the subjective video quality tests. After all tests were completed and we deemed no system acceptable, the process moved to the digital Grand Alliance system development phase, and I was hired by GI.
At GI, I chaired the Grand Alliance’s Video Compression group and was a member of the Grand Alliance Technical Oversight Group (more committees and standards activities). In 1996, the cable industry recognized that, although it was earlier to development in digital television than terrestrial broadcast, its initiatives were not recognized in US and international standards. In particular, they noted the broadcast-centric developments in ATSC, which in some cases were not informed by prior practice in cable. TCI and Time Warner, in particular, wanted to extend the cable presence in standards through SCTE and asked me to step up. I did.
Anything on the DVS agenda worth noting?
The two hottest things right now are new audio and video compression technologies and digital program insertion for ads. Excellent work is underway on both. In new compression technologies, we are assessing potential efficiency improvements and developing profiles for how they might be used in cable service. In program insertion, we have developed the basic cueing technique and have been developing – and continue to develop – specifications for interfaces among the many infrastructure elements that are necessary to make program insertion work.
You wear several other hats, including director of the Rogers Communications Center at Ryerson University. This appears to give you a seat at the content-creation end of the technology spectrum. Is that correct?
That’s correct. Since I joined Ryerson, I have developed three new television studios, including Canada’s first four-camera HDTV studio. Now, I am working to develop a Digital Cinema lab, with 4k x 2k motion imagery, which will be part of CineGrid, a collection of labs and processing facilities connected together by 10GbE fiber links. We will do work in collaborative Production and Post Production, among other things.
On the consulting front, are there any interesting projects that you can mention?
I’m pretty excited about the work I’m doing with Imagine Communications. Imagine has developed an advanced platform that incorporates a radically different approach to video processing and statistical multiplexing that can do really good things for VOD, HD-VOD, switched digital video and IPTV, as these advanced services scale up to mass market.
Imagine Communications is associated with variable bit rate encoding. What’s the elevator pitch for VBR?
VBR has been with us since early days in digital, as has stat muxing in one form or another. It long has been established that using VBR, rather than constant bit rate (CBR), results in better quality and coding efficiency. As you know, the MSOs faced a dilemma in launching VOD – with existing technology, there was no way to provide cost-effective VBR in VOD, so they had to settle for CBR, which resulted in the expected impacts on quality, efficiency, or both.
Imagine does much more than VBR. They’ve developed a platform for what they call Personalized TV, a new content delivery and consumer viewing experience in which the consumer initiates the stream and has a level of control over the viewing experience. They have a radically different approach to video processing and stat muxing that provides a cost-effective solution for VOD and switched digital video. In an existing CBR-oriented VOD infrastructure, it can take the pre-compressed CBR sources and stat mux them. The result is VBR streams that are perceptually identical in quality to the CBR streams, but which require only two-thirds of the bandwidth, allowing 50 percent more streams per QAM channel, as shown at Cable-Tec.
Imagine has also designed an end-to-end VBR solution for VOD, which is backward compatible to CBR VOD servers, allowing more streams per QAM, and at better video quality. In switched digital, the same basic technology is used, but it is expected that the input and infrastructure are VBR-oriented. This results in higher quality sources, and Imagine’s technology preserves that quality, but at considerably lower bit rates. They estimate even greater bandwidth efficiencies here than in VOD, up to 75 percent more streams per QAM channel than conventional stat mux/VBR.
What other technical challenges face MSOs in the area of digital video?
The core challenge, as always, is bandwidth. Operators support analog TV, digital TV, HDTV, high-speed data, voice, VOD and, in some cases, HD-VOD. The latter six continue to grow in demand. For example, HDTV is going mass-market in cable, and competing offerings are ramping up: EchoStar with 30 national HDTV channels, DirecTV with a plan to have capacity for 150 national channels by 2007, Verizon with 20 national HDTV channels. To deal with increased demand and competitive pressure, the operator has to find cost-effective means of maximizing capacity and throughput, which is where Imagine fits in.
Other challenges they face are introducing digital program insertion, expanding interactive service offerings, and meeting the expectations of the “follow-me” video generation (e.g., wireless service extension).
As an academic and practitioner, do you have any comments on the differences between the training of engineers in Canada vs. the United States?
What a loaded question! Actually, I don’t see much difference in engineering training between the two countries. Both are producing engineers with high levels of technical knowledge and skill. Where both could improve is in enhancing graduates’ skills in approaching or developing entirely new technologies and in understanding the business side of things. Over the years, I have had the privilege to work with a lot of great engineers who got it on both counts. It would be nice if these kinds of professionals were the rule rather than the exceptions.