Rich Media Technologies On Mobile Devices

Rich media is different from traditional media, it is composed of text, graphic, image, animation, audio, video and other media objects in the time and space to provide a rich form of expression and interaction. Its main characteristic is based on time or user interaction produce action. Mobile rich media technology is a kind of rich media technology which aim to mobile devices, it has widely sphere of application, including various interactive services, e.g. mobile interactive television, advertising, electronic magazine. On one hand, the demand for developing mobile rich media applications has been increasing rapidly, on the other hand, mobile devices resources constraint will become barrier to mobile rich media application development. This paper mainly studies rich media technologies on mobile devices, the main contents and contributions include:1. According to several typical mobile rich media technologies, e.g. LASeR DIMS, FlashLite, OMA-RME, independently raising an mobile rich media standard u-RMS, the u-RMS standard is divided into three levels which defines displaying, updating and transmission for rich media content. The displaying is based on SVG Tiny1.2, SMIL, DOM Event and extend from these aspects, the updating supports insert, delete, replace the partial contents of current scene, for the transmission, the standard defines the scene unit to guide using stream transport rich media scene.2. Propose the rich media scene control script which fits for embedded environment. The script uses XML markup language to describe grammar, defines elements and attributes to present semantic, and executed by traversing the scene DOM tree, resolves logic controlling, state recovering and device capability using of the scene. Because the script uses the same parse module as scene content and has close relationship with scene progressing, it has the higher processing efficiency and the lower resources consumption. The program through the simulation and analysis demonstrates that has advantages in the field of embedded rich media scene control.3. The Optimized Rich Media Scene Rendering For Mobile Device. Rich media engine is executing environment of rich media applications. The engine needs to consider space occupied and performance problems when designing. This paper introduces the rich media engine which fit for u-RMS standard and researches several key technologies during engine design. Including scene storage, compositing and rendering. In scene storage, researching the progress of scene parse, the storage structure of scene elements and attributes, especially animate elements, in scene compositing, discussing the theory of scene composite and strategy which by decrease traverse scene tree to promote engine performance, in scene rendering, we put forward optimize partial rendering, Grid polygon fill algorithm and the conic to cubic Bezier curve method which fit for mobile devices.4. The text is the important part of the rich media application, the vector font processing performance tends to become the bottleneck in mobile rich media application. According to the features of mobile devices, the paper raises a font structure based on stroke font and Chinese character components, the font structure contains character index, character framework and character components vector info, has advantage in font ROM size and character synthesis speed, it solves the distortion problem of drawing character component also. The paper promotes an outline algorithm for stroke font too. This algorithm uses only once traverse to confirm the polygon outline of the stroke segments and optimize the vertices number of the generated polygon. By the other hand, it considers the abnormal conditions during traversing process and reduces the burden of rendering. The algorithm can also become the common stroke algorithm through a little change.5. In rich media transmission aspects, this paper puts forward the u-RMS transmission framework, defines the transfer protocol format, the protocol uses stream transmitting rich media scene, raises the scene priority ,random access point and redundance transport for better quality of transmission. Analyzing the rich media scene transmit in broadcasting environment, demonstrating the advantages of transmitting scene and update using the same or different channel.6. Based on u-RMS technology, combining with CMMB mobile multimedia broadcasting network and mobile communication network, this paper put forwards the rich media interactive TV demonstration system. From the content and technical point to explore new TV services under the integration of telecommunications networks, cable TV networks and the mobile internet. Strive for the mobile TV grows indispensable media in the future.