Adding Thumbnail to mp4

[phillipsmn]

I was wondering if there was a way to add a thumbnail to an mp4 using transcode video. I know it can be done via ffmpeg doing something like: ffmpeg -i video.mp4 -i IMAGE -map 1 -map 0 -c copy -disposition:0 attached_pic out.mp4 (where IMAGE is the jpg or png that you want to use for the thumbnail) and thought this would be an awesome addition to video_transcoding if it were not already possible.

Is this possible? I tried including some of the ffmpeg commands to the transcode-video one and could not get it to work.