StitcherFive is the core component that executes HTML5 applications and generates MPEG-2 or H.264 compliant streams on a per-user basis. It consists of the Universal Session Manager to setup sessions to the platform, the Application Engine which executes the applications, and the Streaming Engine which is responsible for stitching user interface elements such as buttons, menus, and graphics together with video elements.
Universal Session Manager
The Universal Session Manager (USM) decouples session control from MPEG stream generation. Clients may set up sessions to the Session Manager using a variety of session protocols, such as ICTV_prot, HTTP, and RFB-TV. The USM keeps track of active sessions, handling timeouts and disconnects as appropriate. Client remote control keys are also posted to the USM. Since session initiation, teardown, and posting of keys are specific to the client protocol used, the USM abstracts protocol-specific commands and translates these to generic Streaming Engine and Application Engine interfaces.
The USM has a plug-in architecture that allows deployment-specific protocol support to be added. For example, resource manager plug-ins are responsible for reserving bandwidth for the Streaming Engine in managed networks, such as operator cable or IPTV networks. It requests bandwidth on behalf of the Streaming Engine from either QAM Resource Managers or IPTV Bandwidth Brokers. Other plug-ins take care of specific client protocols.
Every instance of a TV Application runs in its own environment provided by the Application Engine. The H5 Application Engine provides a web browser-like environment in which the application is executed. The application provides an interactive graphical background that can be integrated with all sorts of content accessible via HTTP. To do this, it can access a variety of HTTP based APIs. The content can be data, video, audio, graphics, animations, and text from the operator's infrastructure (linear and non-linear video sources, CMS, databases, billing systems, etc.) and also from internet content and services. A single Application Engine can run multiple TV Applications.
The Streaming Engine provides the platform's core MPEG streaming functionality (both MPEG-2 and H.264). Innovative algorithms in the Streaming Engine ensure a high degree of scalability, making it possible to serve a multitude of subscribers from a single server. Based on screen update instructions and assets from the Application Engine, the Streaming Engine composes and generates individual MPEG streams to each CI+-enabled TV set, STB, or other client.
CloudTV H5™ Components
The image below shows StitcherFive within the context of all CloudTV H5™ Components.