ffmpeg how to overlay a video over an image

here is how to add the FRAMES of a video over an image. the frames of video should have transparency to them.
ffmpeg -i background_image.png -i frames_video%05d.png -filter_complex "overlay" output_video.mp4
-i background_image.png is the input backgound image
-i frames_video%05d.png are the video frames that will be overlaid onto the first input.
see channel video on how to convert a series of images into a video using ffmpeg:
• How to create a video ...
-filter_complex "overlay" is the overlay magic. in this example both background and video would be the same size
output_video.mp4 is the overlaid video name and format.