Of mass market telco TV
The route to market for UK ISPs
However, there are challenges to this approach. Chief is getting a unit retail price below the symbolic £100 ($200) mark, including all markup given in each point in the chain. Next is the raw horsepower needed to process the both the latest video compression technologies (such as H.264 AVC, WM9, Dirac or VP6) in a ‘hot swap’ dynamic fashion and general computation requirements of most modern middleware systems.
The choice of architecture is absolutely critical here, with the current wisdom advising the use of a dual-processor solution – twin microprocessors dedicated to video (DSP) and general (GPP) operations respectively. The market leaders in this field are the ARM9 GPP and Texas Instruments DM642, both having had significant success in recent months. The best choice for these next-generation devices is the newly-announced TI ‘Da Vinci’ platform, which combines the 2 into one powerful chipset.
Surprisingly, despite the demand for hybrid DVB/IP devices, no off-the-shelf software product exists that can be easily integrated into a marketable device. The obvious candidates in the UK market are vendors of MHEG DVB-T interpreters (e.g. Eldon, Ocean Blue, S&T or Cabot) and next-generation IPTV display engines (e.g. Mozilla, Ant, Espial).
The intrinsic barrier to releasing a working hybrid product is getting the two systems to interact transparently, which predicates a need for abstracting the concept of what we know as a ‘channel’, whether it be a DVB MPEG-2 transport stream, a multicast group, a unicast video on-demand feed or a string of material stored on a hard drive. In development terms, it should not necessary to know the source of the channel once the line-up has been dynamically configured; only that it is available to tune to.
Macromedia also offer version 6 of the Flash player that can enable a certain degree of cross-platform abstraction. At some point in the future, more advanced rendering may be available – languages such as XUL, XAML and Lazlo will be the forerunners that mature on the PC desktop before being ported to the television environment.
What the largest platforms have learnt to their cost is that this particular decision is critical to the effectiveness of interactive applications that run on the set-top box and in most cases, generate revenue that help to recoup the original investment needed for the rollout. Television is a fast-moving medium where reaction to change is a survival factor – it is crucial to get applications to the screen in minutes, especially if they are topical. This cannot be done with cumbersome set-top software such as OpenTV or MHP, even if they do offer low-level access to the device hardware needed for gaming and other advanced functions.
Security can be offered on the set-top box in three ways, and is mandated by content rightholders. Identifying individual devices has privacy implications but generally takes the form of using unique serial numbers and hardware (e.g. MAC) addresses. The first is protection against physical theft, or a ‘lockdown’ mechanism, which generally takes the form of blocking the device’s operation should it be used outside the customer’s residence. The latter two are extremely important and interdependent – conditional access (CA – i.e. encryption), and analogue copy protection. Video content must be encrypted from the point of its origin to the point of display, with viewing permissions strictly controlled.
The most resilient and dynamic way to implement security is a more powerful evolution of the ‘smart card’ model – client/server software only. In this model, security client software replaces a physical card and automatically updates itself at specified intervals (so if a weakness is found, it can be patched almost instantaneously), and can also control the second part of the puzzle – analogue copy protection. Copy protection stops viewers from making recordings and is based on technology that exploits the automatic gain control feature of VCRs by adding pulses to the vertical blanking sync signal. Cheap circuits are widely available that will defeat the protection by removing the pulses.
In conclusion, the UK market may look like a more hostile environment in which to operate, but in reality it simply needs a more adaptive deployment model than in other countries. Time will move on and stabilise technology, delivery conditions and viewers’ tastes will mature, meaning that we must focus on providing the most compelling and rich experience rather than the basic bottom denominator that gets the services to market.
Digital TX Limited is a London-based provider of technology and consultancy solutions for interactive digital television and broadband media.Alexander Cameron can be reached at firstname.lastname@example.org.