Furthermore, a better approach would be to conditionally flip the '-shortest'
flag on only if the length of audio exceeds the length of video. If length of
audio is shorter than length of video, the completely correct solution would be
to pad the audio, by doing it in an FFmpeg filter, on the fly, because very
short audios combined with long videos lead to funny results in certain cases.
I don't want to invest the time or effort into doing this right now, but these
are projects for a further time.
