Design And Implementation Of WDM Based Video Process System

With the rapid development of Internet, real time multimedia communication has become one of the key research areas of the network technology. As a late-model network video application, virtual camera disguises itself as a camera device, with which Instant Messenger can play various videos, records, DVD, etc. Recently, comes forth an application which can add cartoon effect to the video, but short of interface to network. In this case, providing a Virtual Camera is necessary.In this thesis, the Windows WDM driver is firstly presented. Then, for the multimedia device's sake, the Kernel stream driver's principle, architecture and the development process are analyzed in details. Integrated the sub-layer WDM driver with the DirectShow's video capture technology; this thesis brings forward a solution scheme of virtual camera. The system architecture is expatiated, especially the prototype of virtual driver and the I/O control of interfaces. According to the characters of video stream, a solution of a efficient buffer is provided for data processing and dimension transform. Besides, the request packets of read and write are disposed in queue, which smooth the delay and jitter of the video and supports the real time video transmission. This virtual driver is built in standard DDK. When Instant Messenger chooses the virtual camera, it can obtain the video processed by the special effect software, so as to transport the video with cartoon effect on the Internet. Finally, the thesis brings forward module test. The results present that this system can achieve the anticipated goal both in function and capability, provided with good expansibility and portability.