Ffmpeg Chromakey

Context: $ARGUMENTS

Quick start

• Green screen over new bg: → Step 1 (pick filter) → Step 2 (tune) → Step 3 (despill) → Step 4 (overlay)
• Export transparent mezzanine (ProRes 4444 / VP9-alpha / PNG seq): → Step 3, then encode with alpha-capable codec
• GPU path (NVIDIA): → Step 1 variant using chromakey_cuda

When to use

• Subject shot on green/blue screen needs a new background
• Keyed subject needs to be delivered with alpha for downstream compositing (After Effects, Resolve, web)
• Uneven green (fluorescent falloff, wrinkles): HSV key instead of chromakey
• Subject has a static plate-background (e.g. locked-off camera): backgroundkey beats chroma
• Bright-on-dark or dark-on-bright with no color cue: lumakey

Step 1 — Pick the key filter