# Video Editing > Video editing pipeline: cut footage, assemble clips via FFmpeg and Remotion. - **Type:** Skill - **Install:** `agentstack add skill-notque-vexjoy-agent-video-editing` - **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior - **Seller:** [notque](https://agentstack.voostack.com/s/notque) - **Installs:** 0 - **Category:** [Content & Media](https://agentstack.voostack.com/c/content-and-media) - **Latest version:** 0.1.0 - **License:** MIT - **Upstream author:** [notque](https://github.com/notque) - **Source:** https://github.com/notque/vexjoy-agent/tree/main/skills/content/video-editing - **Website:** https://vexjoy.com ## Install ```sh agentstack add skill-notque-vexjoy-agent-video-editing ``` Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent. ## About # Video Editing Skill ## Overview This skill implements a **6-layer pipeline** where AI handles judgment tasks (what to keep, what to cut, highlight selection) and FFmpeg/Remotion handle mechanical execution deterministically. | Layer | Name | Mechanism | Primary Tool | |-------|------|-----------|-------------| | 1 | CAPTURE | Inventory source footage | Bash + Glob | | 2 | AI STRUCTURE | Transcript to EDL | LLM judgment | | 3 | FFMPEG CUTS | EDL to segment files | FFmpeg (deterministic) | | 4 | REMOTION COMPOSITION | Segments to TSX composition | Remotion + TypeScript | | 5 | AI GENERATION | Fill gaps with generated assets | ElevenLabs / fal.ai (conditional) | | 6 | FINAL POLISH | Human taste layer | Human + NLE | --- ## Reference Loading Table | Signal | Load These Files | Why | |---|---|---| | `references/preflight.md` | `preflight.md` | Before Phase 1 | | `references/phase-commands.md` | `phase-commands.md` | Each phase | | `references/errors.md` | `errors.md` | Error Handling | | `references/ffmpeg-commands.md` | `ffmpeg-commands.md` | Phase 3, Proxy | | `references/remotion-scaffold.md` | `remotion-scaffold.md` | Phase 4 | ## Instructions ### Preflight (Run before Phase 1) **Hard requirements** (BLOCK if missing): `ffmpeg` (all phases), `node` (Remotion / npx). **Soft requirements** (WARN if missing): `remotion` (only required for Phase 4). Preflight script (dependency checks, install hints, exit codes): `references/preflight.md`. --- ## Phase 1: CAPTURE **Goal**: Inventory all source footage and confirm files exist on disk before any processing. **Constraint**: Source files are read-only. All FFmpeg commands write to new files only. Never overwrite source footage. Steps: locate source files (find), inspect each with `ffprobe`, generate proxies for files >10 min (see `references/ffmpeg-commands.md` -> Proxy Generation), create working directories (`segments/`, `assembled/`). Full command block: `references/phase-commands.md` -> Phase 1. **Gate**: Source files confirmed on disk. File list written to `source-inventory.txt`. Proceed only when gate passes. --- ## Phase 2: AI STRUCTURE **Goal**: Analyze content and produce a written EDL (`cuts.txt`) that drives all downstream cutting. **Constraint**: `cuts.txt` is the contract. The EDL file is the only source of truth for downstream phases. Do not hand-edit FFmpeg commands — generate them from the EDL. **Constraint**: Before writing the EDL manually, run FFmpeg scene/silence detection. Detection output informs judgment, not replaces it. Steps: transcribe with whisper/AssemblyAI, run scene/silence detection, apply judgment (what advances narrative, what is filler, target duration), write `cuts.txt` in EDL format `START_TIME,END_TIME,LABEL`, review for overlap and total duration. Full command block and EDL format example: `references/phase-commands.md` -> Phase 2. **Gate**: `transcript.txt` exists. `cuts.txt` written to disk. Proceed only when both files exist. --- ## Phase 3: FFMPEG CUTS **Goal**: Execute the EDL deterministically — one FFmpeg cut per segment in `cuts.txt`. **Constraint**: Batch-cut from EDL using a loop. Do not create individual FFmpeg commands per cut. This ensures reproducibility and review capability as a list. **Constraint**: Always generate concat-list.txt from cuts.txt order, not from shell glob. Shell glob (`segments/*.mp4`) sorts alphabetically, not by EDL order. Steps: batch-cut from EDL with while loop (libx264/aac, `-avoid_negative_ts make_zero`), verify segments, generate `concat-list.txt` in EDL order, concat with `-f concat -safe 0 -c copy`. Full command block: `references/phase-commands.md` -> Phase 3. See also `references/ffmpeg-commands.md` -> Batch Cutting. **Gate**: All segment files exist. `assembled/rough-cut.mp4` written to disk. Proceed only when gate passes. --- ## Phase 4: REMOTION COMPOSITION **Goal**: Wrap segments in a Remotion TSX composition for programmatic overlays, titles, or transitions. **When to use**: Only when rough-cut.mp4 requires programmatic elements (animated titles, lower thirds, caption tracks, brand overlays). If rough-cut.mp4 is sufficient, skip to Phase 6. **Constraint**: Layer 4 requires TypeScript/React. Hand off to `typescript-frontend-engineer` for TSX work; return to `python-general-engineer` for Phase 5 onward. Steps: initialize Remotion (`npm create video@latest` first time; otherwise `npm install @remotion/cli @remotion/player remotion`), scaffold composition (see `references/remotion-scaffold.md`), render with `npx remotion render`. Full command block: `references/phase-commands.md` -> Phase 4. **Gate**: `assembled/remotion-output.mp4` exists. Proceed only when gate passes. --- ## Phase 5: AI GENERATION **Goal**: Fill genuine gaps in source material with generated assets — only when needed. **Constraint**: Check whether existing footage covers the gap before generating anything. Generate only what doesn't exist. Decision tree: cut around the gap → update cuts.txt and re-run Phase 3; voiceover → ElevenLabs (authorization required); music → fal.ai (defer to fal-ai-media); b-roll → fal.ai (defer to fal-ai-media). ElevenLabs Python helper, authorization pattern, and save-to-disk flow: `references/phase-commands.md` -> Phase 5. **Gate**: All required generated assets saved to `assets/` directory before proceeding. --- ## Phase 6: FINAL POLISH **Goal**: Deliver assembled output and hand off taste-layer work to human. **Constraint**: Layer 6 is human territory. The skill assembles; the human finishes. The following require human judgment and should not be attempted programmatically: - Color grading and color matching between clips - Music timing and volume ducking - Caption style, font, positioning - Transition timing and style - Final audio mix levels Handoff template (`handoff-notes.txt` with source list, EDL, rough-cut path, remaining-for-human checklist): `references/phase-commands.md` -> Phase 6. **Gate**: `assembled/rough-cut.mp4` (or `assembled/remotion-output.mp4`) exists. `handoff-notes.txt` written to disk. --- ## Error Handling Common errors (missing source files, FFmpeg codec errors, Remotion composition-not-found, concat-order bugs, ElevenLabs 401) and fixes: `references/errors.md`. --- ## References | Reference | When to Load | Content | |-----------|-------------|---------| | `references/preflight.md` | Before Phase 1 | Dependency check script: ffmpeg, node, remotion | | `references/phase-commands.md` | Each phase | Full shell command blocks for Phases 1-6 and gate checks | | `references/errors.md` | Error Handling | Error matrix with causes and fixes | | `references/ffmpeg-commands.md` | Phase 3, Proxy | FFmpeg recipes: timestamp extraction, batch cutting, concatenation, proxy generation, audio normalization, scene/silence detection, social reframing | | `references/remotion-scaffold.md` | Phase 4 | TSX composition scaffold, render command, reuse patterns | - [Remotion docs](https://www.remotion.dev/docs) -- TSX composition API - [FFmpeg docs](https://ffmpeg.org/documentation.html) -- Flag reference ## Source & license This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code. - **Author:** [notque](https://github.com/notque) - **Source:** [notque/vexjoy-agent](https://github.com/notque/vexjoy-agent) - **License:** MIT - **Homepage:** https://vexjoy.com Install and usage instructions live in the source repository linked above. ## Pricing - **Free** — Free ## Security capabilities Automated source analysis of v0.1.0 — what this tool can access: - **Network access:** no - **Filesystem access:** no - **Shell / process execution:** no - **Environment & secrets:** no - **Dynamic code execution:** no *"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.* ## Versions - **0.1.0** — security scan: passed — Imported from the upstream source. ## Links - Listing page: https://agentstack.voostack.com/l/skill-notque-vexjoy-agent-video-editing - Seller: https://agentstack.voostack.com/s/notque - Browse the marketplace: https://agentstack.voostack.com/browse --- Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.