📦 Code: github.com/USER/ffmpeg-upgrade-check (replace before publishing)

TL;DR

FFmpeg 9.0 "Lei" (released 2026-08-04) bumped every core library and removed some old support. Exit code 0 does not mean "same output". We'll build a ~60 line Python script that runs your real command lines with the old and new ffmpeg , then diffs ffprobe fields and SSIM. Python 3.10+, any ffmpeg.

🎯 What we're building

A script that takes two ffmpeg binaries, one source clip, and a JSON file of your recipes, and prints OK , DIFF , or FAIL for each one. Think of it as a snapshot test where the snapshot is "whatever the old build did".

What changed in 9.0, per the release coverage I read (news write-ups, not the changelog itself, so skim the official notes for your own recipes):

Area Change

Libraries Every core library got a major bump; libavcodec and libavformat are in the 63 series

Removed Standalone CELT decoding and Ogg/CELT parsing (Opus is not affected)

Removed NVIDIA Video Codec SDK versions before 11.1, plus…