i like that you think about the different formats and that there might be reasons to use them =)
…to me personally … i wouldn’t see why i should transcode a video (for which i would need to download the best quality file first) to then watch the potentially lower quality video clip 
i could imagine i might upload a video in a lower quality for mobile as well - but not with the same machine that should play it in the end
did you have a look at
and how the concept is there …? maybe thinking one or two moments more about how to achieve the common goal the best way saves some time later on in the process 