Hi
Thank you very much for providing an alternative link which did work from
China (all in all, I needed two hours to download your video, i.e. 100 minutes for the first three minutes, but the remaining part in 20 minutes).
Your 142 meg video file clearly demonstrates how, from a clean html file (book), your bash script has the ability to produce both a clean EPUB and a clean PDF, -including metadata thanks to a second bash script. You also show how you can add some text and a cover to the original file and produce again a complete EPUB and PDF.
So congratulations for this first but quite important step.
What will be the next step? When do you plan to release your script(s)?