Top-down is the order I, as a non-professional audio/video person, kept migrating my A/V content from one media type to the next as technology advanced over time. It's been quite the adventure.

If you do not recognize the acronym OTA then you might be too young to remember that in the foggy past all content was broadcast over the air and you sat passively in front of your radio or TV. You never knew when your favorite song would play on the radio and would feverishly rotate the tuning knob, or push 1 of those 5 preset buttons, to sweep through the noise and static, listening for it. If you had a TV it was probably black and white with three channels to choose from, ABC, CBS or NBC, which the rabbit ears antenna might tune-in from the background radiation if it was pointed in the correct direction and the transmitting station was close enough and still broadcasting for the day. Sometimes you'd position your  sibling or dog next to the TV to improve reception.

Obviously I never owned any "OTA media", but what I heard and saw was the foundation for the content that I wanted for myself. In the audio world I have essentially no content that I personally created and own, it's mostly music sold by other artists. The music content owners do all the work of transferring their music to the next medium, all I do is re-purchase the higher quality content.

Video is another matter. True, there are movies that I re-purchase if I want the best viewing experience - I first bought Alien as a Video8 tape, now I have it in 4K UHD on a Blu-ray disc. I'm referring to home movies.

My home movies started as 8mm film, but over time were transferred to Video8 tape, then to DVD and finally to MPEG-4.  What I present to you now is an example of this decades long process applied to original content that was filmed 44 years ago. Thus, while the movie has remained visually unchanged over the decades, this sample is in a modern digital form, consumable from an iPhone to an iMac, streamable on the web for anyone to view.

After watching the movie check out these possibly interesting technical details.