IBC2015 Q&A: David Wood, chair, DVB-UHDTV Commercial Module
The Digital Video Broadcasting (DVB) Project continues to be one of the most important industry associations when it comes to helping define the future of broadcast services. And with a broadcast future full of potential via UHD, IP, and other services, the importance of DVB cannot be understated.
At IBC, the organisation will once again be at the centre of many discussions of the future, and the DVB stand (1.D81) will once again be a place to see the future. David Wood, chair of the DVB-UHDTV Commercial Module, offers SVG Europe his insights into the future of broadcasting services in Europe and beyond.
UHD is top of mind these days, and DVB has been hard at work ensuring that terrestrial broadcasting is ready for the future. Production professionals are intrigued by UHD but concerned with how it will be delivered to customers. Can you provide a quick update on recent DVB accomplishments with respect to preparing for UHD? What are some current timelines for making it a real-world reality?
DVB has already produced a UHDTV specification for what is termed UHD-1 Phase 1, and, indeed, this is being used today. So, in that sense, DVB UHD-1 is already a reality.
In addition, DVB is working on systems that will include additional features. One of the additional features is termed High Dynamic Range (HDR) and is intended to give future UHDTV displays that have a higher-brightness capability the signals to exploit it. The technology for this has yet to be agreed [on], but we hope to have a specification such that services can begin in 2017. Broadcasters may choose to start services now with Phase 1 or wait for the HDR specification to be available, which would probably mean their starting services in 2017 or later.
Broadcasters may also choose to wait for a further feature, High Frame Rate (HFR), in which case they may start services in 2019 or later.
Many of the terrestrial broadcasters are challenged financially, particularly the public ones. How do you see the work DVB is doing helping them make the move to UHD?
DVB provides open standards that can be used for terrestrial broadcasting. Open standards bring larger markets and lower costs for consumers, so DVB is helping broadcasters make the move to deliver UHDTV to the public.
Broadcasters are members of the DVB groups that decide on requirements and specifications, so they can make sure that their circumstances and needs [influence] the standards.
Given that delivery of UHD content via the Internet is already here, do you think it is imperative that terrestrial broadcasters offer a UHD service to keep up with those services? Is there a danger in lagging behind technologically?
Terrestrial broadcasters have to decide for themselves when and where they provide UHDTV broadcasting services. This is not a judgment for the DVB Project to make.
However, without prejudicing any action they may take, we could note that current UHD displays provide only higher spatial resolution and there is no dramatic improvement in image quality over good HDTV quality when the TV set is viewed at distances of four times picture height or more. More-significant improvements in quality seen may come with additional features in future years.
DVB also has a number of announcements with respect to the use of IP. How do you see the DVB work affecting the type of services broadcasters can offer?
Already, for more than 10 years, DVB has been supporting IP delivery of content. All of our second-generation standards support delivery of IP traffic over DVB channels. This is especially relevant for data transmission via satellite, where DVB specifications are the de facto standard. In addition, DVB has provided the necessary specification for delivery of DVB services over managed and unmanaged IP networks. For the unmanaged case, DVB has defined the DVB MPEG-DASH specification, which is a broadcast-centric version of MPEG-DASH.
MPEG-DASH is another concept that a lot of broadcasters hear about but might not fully comprehend. What work is DVB doing on MPEG-DASH, and what will it mean to broadcasters and their viewers?
MPEG-DASH is a method of streaming video that adjusts the image bitrate to suit the domestic user’s available Internet data rate, which can vary. This can make Internet-delivered video more comfortable to watch. MPEG-DASH will probably be widely used for Internet-delivered UHDTV.
Last year, DVB has published the specification “DVB MPEG-DASH Profile for Transport of ISO BMFF-Based DVB Services Over IP-Based Networks.” This document defines a subset of MPEG-DASH to be used for delivery of DVB services via DASH. It reduces the number of options MPEG-DASH provides, making implementations easier. This specification lowers the implementation threshold for OTT services over DASH for broadcasters and CE providers.