I have seen commands like this online:
ffmpeg -i video.mp4 -i image.png -map 1 -map 0 -c copy \ -disposition:0 attached_pic out.mp4
However these command don't work as advertised with Windows Explorer, while other tools such as AtomicParsley and TagEditor do. What I mean is that, is appears that FFmpeg does add an image stream, but the thumbnail is not visible with Windows Explorer. Does FFmpeg have some command that will work with Windows?