- webview fallback with canvas capture for codecs not supported in the default player
- detecting blank frames and diff between thumbnails to maximize variety
- UI integration to visualize progress and pending thumbnails, batched updates to the gallery
- versioning scheme and backfill for missing/outdated thumbnail formats
Honestly, a day seems rather optimistic to me. Maybe if I was an expert for this platform and would have implemented a similar feature before, then I could hope to do it in a day.
If I had to handwrite it and estimate it for Scrum at work, I‘d budget a week.
Video thumbnails are a different beast altogether. And you might want to double check your assumptions about security considerations. If any of your ffmpeg, opencv, pyscenedetect code is running on your server, it might well be exploitable.
Ironically, already another user in this comment section was concerned about the security of my nonexistent backend.
But it’s good to know, I was not previously aware that video processing on the backend is a common source of vulnerabilities.