It's surely interesting that you try to figure out the "state of art" but as far as I see the amount of information is too low to recover more readability, and that was my estimate even before your experiments. The way I saw it, the algorithm would have to model the "compression interference patterns" to do that, and even if something like that existed the amount of information seems to be far too low.

If it's really about the given talk and not exploring state of art in algorithms for recovering of the (textual?) information lost due to video compression, you'd be better off to communicate

1) with Dr Hipp who gave the talk -- he published the more recent original slides on the sqlite site:

https://www.sqlite.org/talks/

so it could be reasonable he'd be willing to publish these older slides (which he probably considers in some aspects outdated). Then only if that fails:

2) with the author of the video who possibly still has a higher quality version of the video, if the quality was dropped during the video compression or preparation for youtube, e.g. while trying to reduce bandwidth or reencode from the native recording format.