MediaLooks Video Mixer is a DirectShow filter for real-time mixing of several video streams coming from different video sources (such as camera, files or static images).
MediaLooks Video Mixer features:
Change output image size even during playback
specify source/destination rectangles for each input video
specify alpha (transparency) for each stream
allows different input colorspace, size and FPS
movie files can be used as input streams
images can be used as input streams
output FPS can be automatically or manually set
allows input format changes (size and colorspace) during playback