> Seems like this is something machine learning would be very good at, given that commercial visuals look very different from “real” show visuals

This feature was in MythTV literally 10+ years ago. Commercials are very easy to detect using simple methods [0].

[0] https://www.mythtv.org/wiki/Commercial_detection

As far as I know audio levels in commercials are different too. I don't know the exact number, but I seem to recall reading some time commercials are usually 30% louder or something. They are definitely noticeably louder than most shows, except maybe sitcoms.

ETA: Looking it up it looks like America has laws about this now. I'm in Canada I'm not sure if it's the same here.

And on further reading, it seems like advertisers may be using excessive compression to artificially boost loudness and skirt the law.

There's volume and then there's "loudness."

Even if peak volume is under some prescribed maximum, compressed audio can feel very loud. Commercials often leave very little dynamic space, which makes them jarring in that they feel "loud."

Movies also have loud scenes which would false positive.

Why bother? There are already known ways to detect commercial breaks like so many milliseconds of black screen, and such. Also, there are very few commercials on television at any time, including local ads. You could just fingerprint them.