When I capture a video, Replay Video Capture (RVC) writes two files. First, it writes an MPG file. This file is sitting there when I finish recording. It also writes an MP4 file that is not finished when the recording is over and I exit RVC. What happens is ffmpeg.exe continues to run in a console window, and appears to be writing this other file. When it finishes, the MP4 file is about half the size of the MPG file.

What is the purpose of creating two files.