Videostream capture

I need someone to write a piece of software that can do the following at the same time: - Capture the computerscreen and save it to a video file (.avi or .mp4). (screenrecording) - Capture a H264 videostream from the network (stream includes sound) and save it to a file (.avi or .mp4). These two videofiles will be combined in other software for lecture capturing. Therefore the two recorded videofiles should be in (near perfect) sync. Shouldn't be that difficult? I'd love to hear from you guys.