video-overlay

原文涵盖的主题

• Video overlays & compositing
• Pick the overlay type
• Transparency rules (learned the hard way)
• Timed windows
• Positioning accurately — DON'T iterate-and-eyeball
• Static target (fixed scene element)
• Target that's hard to pin by eye, or that moves
• Verify

Full Production Studio note: this skill drives the toolkit in agamm/video-agent. Clone that repo and run your agent inside it for the scripts/paths below to work; the guidance itself is usable anywhere. Deterministic compositing of a known asset onto video. (For generative edits that reimagine the footage — recolor objects, add smoke/fire — use grok-video-edit instead.) | Asset | Command / approach | |---|---| | Text label | overlay-text (PIL render; mise ffmpeg lacks drawtext) | | Multiple text labels | overlay-texts (one pass, e.g. countdown) | | Static image / logo | overlay-image | | Static transparent graphic | RGBA PNG + ffmpeg overlay (alpha is native — no colorkey) | | Animated transparent effect | RGBA PNG sequence + ffmpeg (see below) | --x/--y: pixel offset, center, or ffmpeg expr (W-w-10 = 10px from right edge). Static transparent overlay → use an RGBA PNG directly. overlay handles 8-bit alpha natively. No colorkey. Animated transparent overlay → use an RGBA PNG sequence, NOT a GIF. PIL-saved GIFs quantize to a 1-bit palette and overlay-gif silently fails to composite their transparency. Render frames as seq/000.png, 001.png, … and feed: If using a GIF with colorkey any

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