C++ library to capture webcam to file (audio/video, wmv format)

C++ library that will capture/record a usb webcam and save audio video file in wmv format. The library will be used on Windows . Example of API functions will look like: ... int N=StartRecord(string filename, ...); // N<0 on failure, N=0 on success int N=StopRecord(...); // return N<0 on failure and N=number of seconds captured on success