I know Lemmy hates AI, but this actually would be a perfect use for it. The problem is the idea of what an ad is. Yes, you could try to use secondary characteristics like image color or sound normalized volume (WhyTF do youtube ads still sound 3x louder than content? are we living in cable era again?), but they would be error-prone for any content more visually intense than a podcast. They would also not capture sponsorblock content like "I love showing you all these foreign countries but what I love even more is having my internet connection secure" that match the video flow. A crowdsourced lookup table of all known ad clip fingerprints would go a long way, until ad videos themselves start being AI-generated on the fly for that sweet personalization revenue.

No, what I really want is to distill the idea of what I want to see into an AI and have it filter out what I don't want to see for me. I know an ad when I see one, so AI can too. Pre-roll/mid-roll ads? Gone. Sponsorblock content? Gone. Like and subscribe? Skipped as if it didn't exist. Virtual billboards on the sidelines of sporting events? Overlayed with kittens. Idiocracy banners squeezing the video from either side? Cropped and rescaled. Watermarks? Excised and content-aware-filled.

The last frontier is when the content itself is secretly an ad, imprinting upon you some idea or point of view. You'll have to watch out for that one on your own.