Multi-point Video Conferencing System Display Unit, The Design And Realization

With the development of network and multimedia technology, the video conference system will apply more widely, but the existing systems don't have the mature technique and devices in multi-image composition and displaying, so synchronous process and image composition of multi-meeting-place in a single device is a hot topic that many project team studies. The designed MDU (multipoint display unit) in the paper can decode many video streams that are compressed and coded synchronously, and compose different images into one big image, then output the image to various devices of video display.This paper does a deeply study about the standard of H.263 video codec and the bootload process of TMS320DM642 DSP, and proposes a method of second-level load to actualize the system boot and a method of multi-image composition, then designs a kind of strategy of video frame buffer based on hardware. According to the features of the TMS320DM642 DSP, the paper design the video decoder based on standard of H.263. In order to meet the request of running several video decoders synchronously, key parts of decoder must be optimized.It is used the idea of modularization in the design of whole system, MDU is divided into module of network receiving, module of video decoder and module of display. These modules are independent each other, therefore all modules are designed easily and feasibly.MDU that designed in the paper already succeed in using in actual video conference system, and gets better results. Because MDU resolves the problem of multi-image composition and display, it will have a vast of market foreground.