Agile IP Video Delivery: Redefining STB Software Architecture December 2012 Espial Group 1997-2012. All rights reserved
Executive Summary Today s consumers have come to expect a sophisticated video user experience based on their daily interaction with tablets, smart phones and their favorite websites. They also expect a blended video user experience with social media integration, quick access to their favourite content and rich personalization. Unfortunately, pay-tv operators face major challenges to deliver a robust TV experience that matches consumer expectations, especially on set-top boxes (STBs). Some of the challenges they face include: The inability to rapidly innovate and introduce new applications High STB porting and introduction costs Inconsistent experience across devices Vendor new feature lock-in Leading operators are now looking at a multipronged strategy to address these issues and power the development of a compelling user experience including: Cloud UI delivery New advertising models Rapid application innovation Interactive content Integrated web and social applications The newest HTML5 standards This paper reviews the technology and business changes required to address these difficult challenges. It describes how to leverage recent hardware and software innovations to implement an STB software architecture, this provides pay-tv operators with agility, allowing them to deliver an unprecedented user experience with faster time to market and lower costs. 02
STB Challenges and Innovations Let s start by looking at the challenges associated with current STBs. First, they are faced with non-standard and highly constrained graphics for user interfaces. Older generations of STB hardware are missing the CPU speed, RAM and hardware acceleration features necessary to render rich graphics. As well, client software vendors are only able to expose limited capabilities via APIs and interface development tools are not supported by industry standard authoring tools. Next, applications innovation is gated by software vendors. The STB software is often delivered using closed implementations offering limited or no flexibility for 3rd party applications integration. Finally, porting is time consuming and expensive. The divergence between chipset vendors has meant that most software was hardware specific. Moreover, the lack of standard approaches to common functions such as streaming means that these functions require significant effort to migrate between STBs. Several innovations have now set the stage for a new approach to set-top box middleware including a transition to IP video service delivery, industry initiatives, standards, and hardware and software technology advancements. Let s consider each of these in turn. There is a broad shift toward the use of IP video delivery. Cable TV has traditionally offered QAM-based content distribution with a proprietary back-channel. Cable companies are now moving to either a pure IP-based video services delivery or continuing to use QAM-based content distribution with IP-based interactivity. For in-home delivery, they are looking at one of two approaches. The first is a pure IP approach based on direct IP to the STB from an IP based headend. The second is accomplished using an inhome gateway based on IP communications to other devices. This is a hybrid approaches using existing cable head-end to a cable hybrid gateway with IP distribution in the home to an IP STB. This approach enables transition for those Service Providers with an existing cable based solution. The semiconductor industry is also driving significant changes. The explosion of consumer devices is accelerating innovation and lowering costs. As a result, more powerful STBs are appearing featuring processor speeds in the 800MHz 1Ghz range; dual-core processor architectures; graphics hardware acceleration for 2D, Blit, OpenGL; and more of RAM to provide improved browser UI rendering. There are several software innovations that operators can leverage for STBs. First, HTML5 is now being widely adopted as the standard for video user interfaces on all devices. As part of this, WebKit is the most widely adopted HTML5 rendering engine across consumer devices and is the de-facto standard for STBs and gateways. Driven by the mobile and consumer industries, embedded browsers are being optimized for deployment in STB environments with support for advanced graphics capabilities like OpenGL and CSS3; smaller resource footprints through highly optimized memory and resource management; faster porting to different environments; media extensions for video 03
delivery. Open source initiatives like gstreamer are providing additional valuable STB software components. Finally, there are multiple standards initiatives driving the evolution of STBs. For example, the Digital Living Network Alliance (DLNA) has focused on standardizing the delivery of media between devices in the home. The Digital Transmission Licensing Administrator (DTLA) licenses Digital Transmission Content Protection (DTCP) technologies, which are approved by studios to provide content protection for media transmitted between devices. As well, operators in the United States are aligning on initiatives to standardize the STB software stack. These initiatives provide an abstracted porting layer to simplify and unify the integration of the applications and control layers. It is based on the prediction that all applications will migrate to HTML5 and the control will move into the cloud. The initiative intends to foster broad multi-service operator (MSO) adoption of a standardized software stack that will enable faster deployment with lower costs. In summary, the transition to IP video service delivery, vendor innovations and standards initiatives open the door to new IP STB software architectures. A New STB Software Architecture Next, let s examine the principles for a new client architectures for a STB. The developments described above allow for a new STB software approach that is vendor independent, open, flexible and provides a dramatically improved user experience. The new STB client architecture is based on several key principles. Let s consider each of these in turn. As a start, the architecture needs to leverage web technologies to enable standardization of interface development across multiple devices and enable innovation driven from a vast pool of web developers. It also needs to improve time to market using industry-standard tools. It must be hardware independent, which permits the service provider to add new devices at lower cost, with better performance, and functionality without any back-office changes. It provides a seamless user experience between web browsing and the core TV applications like the EPG. It supports a full web browsing experience, differentiating implementations from the TV experience. It keeps the client simple by migrating heavy lifting functions to the server. Finally, it supports consistent behavior between devices by leveraging server -side capabilities. The ideal STB architecture, based on these principles, is described in figure 1 (next page). It assumes that the chipset or system on a chip (SoC) supports the features and performance to match the target functionality the operator wants to deploy. The chipset vendor will also offer specific software components associated with their implementation identified in figure 1 as SoC, including drivers for the capabilities provided. The chipsets are then used by STB and gateway manufacturers who build essential capabilities such as LEDs, power controls and features like PVR. These functions are exposed by the manufacturer using a software development kit (SDK), which is used by the STB client software. The client software must take full advantage of SoC and STB software functions and provides a porting layer to facilitate fast and low cost porting between platforms. The client layer includes must including the following elements. First, it requires an HTML5-based UI rendering engine to achieve several key objectives. This provides maximum UI flexibility and consistency with other IP devices. It also allows the operator full control of user experience using HTML5. As well, it supports browsing to either a walled-garden environment or with full access to the open web. The browser must be developed and 04
tested on an ongoing basis to maintain support for proper rendering of the most complex web pages. The HTML5 support also requires an application framework to provide a rich consumer experience for widgets such as weather, news, games, sports; access to operator applications such as videoconferencing and caller ID; integration with OTT video applications such as HBO Go and ESPN; and, web content applications such as the shopping network, voting, and play along. This framework is explained in greater detail in a following section. The second element of the client layer requires common enabling functions. These are standard enablers for IP video delivery and include industry initiatives that are pushing standardization of components across multiple platforms and driving down time to market, risk and porting costs. These functions include content protocol support for H264, AAC, MP2TS, MP4; content delivery support for Microsoft smooth streaming, HLS, DLNA DMP, DASH; content protection including Microsoft PlayReady and DTCP/IP. Thirdly, the client layer must support core video applications including STB management, conflicts scheduling management, scheduling, parental controls, EPG, DVR and VOD. It should also provide trigger handling for advertisements and merchandizing. Finally, it should provide a highly optimized architecture to separate application logic from the user experience. Fourth, the client should offer a porting layer to attain the lowest possible time and cost of porting between STBs and SoCs. This is achieved by abstracting the hardware-specific items from the application layer. Figure 1: Redefined STB software architecture Overall, an HTML5 STB client offers highly desirable benefits such as a very rich user experience, but care must be taken to realize optimal performance. Espial is working with industry leaders on their reference 2013 platforms. Espial has categorized STBs into three main categories to understand the specific balance between performance and standards. STB Capability Taxonomy 05
To fully leverage the advantages of a HTML5 STB client, an operator must carefully select the STB platform they will use. Espial has divided STBs into three categories and analyzed their benefits as illustrated in the table on this page. First, are limited capability STBs which are unable to support a HTML5 browser and have limited graphics capabilities. These require a highly optimized solution such as Espial STB Middleware. Second are transition STBs that are capable of supporting an HTML5 browser yet lack full graphics support. The third category are STBs fully capable of supporting HTML5 browsers and advanced graphics. By examining their existing and planned STB models, pay-tv operators can deliver a highly consistent user experience across multiple STBs with the web and advanced video applications appropriate to each model. Coupled with a powerful IP Video Back-office platform, the operator can also easily support user-purchased devices, such as Smart TVs, that ship with a full HTML5 web browser. Espial recommends that operators carefully evaluate their STB strategy in combination with an associated IP Video Back office to support future evolution. The IP Video back-office is an important element for providing a rich crossdevice, multiscreen user experience. The platform should provide HTML5 UI distribution and management from the cloud. Management touch-points include subscriber, account, user, device management; product, promotions and package management; consistency of delivery between users accessing services across multiple devices. 06
App Framework For Rapid Innovation Espial provides an advanced application framework to accelerate delivery of cloud-based web applications. The framework is based on JavaScript API functions for TV, operator, and 3rd party web apps. For the core video experience, the API includes: Application discovery access to cloud TV app repositories to list available apps, categories, app URL location, icons, and pricing. Application management authenticate, purchase, start, stop, and manage the switching of browser windows between TV, HTML UI and web apps. IP Back office management the ability to handle app billing, account management, in -app purchases, and reporting. App display ability to control whether the TV app is rendered full-screen, overlay on video, half-screen or widget style. App settings ability to manage privacy, parental control, storage, cookies, login, permissions for middleware access (e.g. channel zapping, or content-bound triggers). The API functions for the Web Apps include: Interactivity triggers register for automatic content recognition (ACR) triggers based on live TV to launch context-sensitive apps. For example, the ACR could identify a particular live channel such as CNN and notify the cnn.com web app, which in turn launches an overlay of additional links or information. Core TV Apps ability for web apps to control video playback (full screen, embedded, etc), channel zapping, or retrieve guide information. Companion devices allow web apps to receive and send notifications to secondscreen apps and receive remote navigation and input including gesture-based commands. Multi-user manage sign-off and settings for multiple users. App storage leverage HTML5 s persistent storage feature to save application state info, user information, and login state. Offline cache leverage HTML5 s offline application cache to facilitate caching of app content, resulting in better responsiveness. Conclusion By leveraging the new STB client architecture based on HTML5, advanced SOCs, web standard technologies and other components outlined in this paper, pay-tv operators can achieve: Respond more quickly to consumers and competitors with rapid service and application innovation through tight coupling between the STB hardware vendor and quicker integration between TV apps and web apps.. Faster and less expensive introduction of new STB hardware and associated features through lower costs and faster software porting. High impact user experiences based on industry standard web approaches coupled with the ability to render rich graphics. Consistent multiscreen user experience by leveraging common web technologies and methodologies across devices. Service Providers can take advantage of Espial s leadership, innovation, and proven track record of successful production deployment with confidence in business success. 07
CONTACT US Corporate Headquarters 200 Elgin Street. Suite 1000 Ottawa, Ontario K2P 1L5 Canada TEL: +1.613.230.4770 TF: +1.888.437.7425 FAX: +1.613.230.8498 United States 3375 Scott Blvd. Suite 130 Santa Clara, CA 95054 TEL: +1.650.943.8600 FAX: +1.408.747.1025 European Headquarters First Floor 335 Cambridge Science Park Milton Road, Cambridge Cambridgeshire, CB4 0WN TEL: +44.1223.716.400 Asia-Pacific / Tokyo Sales Office 815 BUREX Kyobashi 2-7-14, Kyobashi, Chuo-ku, Tokyo 104-0031 Japan TEL: +81.3.6802.7076 Espial Expertise Espial has an excellent track record of leadership IP video delivery with advanced client and server technologies: Espial embraces HTML5 as the advanced user interface platform of choice and is a leading global provider of HTML5 browsers for the connected TV market. Espial is a leader in providing WebKit-based HTML5 browsers and is driving industry momentum in connected TVs as well as STBs and gateways. Espial has optimized base WebKit software for an improved video user experience: Performance: the WebKit engine is highly tuned to ensure optimal performance performs on resource-constrained devices. Porting and customization: a porting layer is available to ensure rapid time to market and customization Espial focuses on applications development by underware provided by the STB manufacturer rather than taking a build to the metal approach. This underware is now becoming standardized based on SoCs, open source components and industry standard initiatives for which the Espial client architecture is highly optimized to provide a superior user experience. The Espial Media Service Platform provides a full featured IP service delivery platform providing a seamless multiscreen video experience with excellent application performance, intuitive user interfaces, carrier-grade performance and scalability, and a platform capable of delivering on innovative use cases. Espial MediaBase provides a full featured IP video CDN for multiscreen delivery based on COTS hardware and widely deployed across the globe. 08