Quick Summary

My old slideshow-to-video pipeline had three manual steps that silently corrupted sync on files over 4 minutes.

Swapping out the music layer reduced a 23-minute manual QA process to under 4 minutes per batch.

The boring fix (format normalization before merge, not after) was the one I kept ignoring for eight months.

I've been maintaining a content pipeline that takes static image sets, pairs them with background audio, and exports short video slideshows for a client who runs a language-learning site. The Slideshow Maker part sounds trivial until you're debugging why a 4-minute export has audio that drifts 1.3 seconds behind the visuals by the end. That's the kind of thing a client notices immediately and you notice approximately never during local testing.

This post is a code review of my own old process. Not a rewrite — just annotations.…