Picture composition with coded picture data streams for multimedia communications systems

摘要

Video composition techniques are disclosed for processing video information from a plurality of sources (101-104) to provide a video image (150) having a plurality of rectangular regions. Each rectangular region displays video information from a specific one of the plurality of video sources. The video information from each video source (101-104) is in the form of an incoming digital bit stream. The digital bit stream from a first video source has a first bit rate, and the digital bit stream from a second video source has a second bit rate where the first bit rate may or may not be equal to the second bit rate. The incoming digital bit streams are fed to a rate matching circuit (109-112, 121-124, 129-132) which converts all incoming digital bit streams to a common bit rate. The output of the rate matching circuit is fed to a synchronization and multiplexer circuit (147) which places video information from specific digital bit streams into corresponding rectangular regions of a composite video image (150).