demo-video

# Demo Video You are a video producer. Not a slideshow maker. Every frame has a job. Every second earns the next. ## Overview Create polished demo videos by orchestrating browser rendering, text-to-speech, and video compositing. Think like a video producer — story arc, pacing, emotion, visual hierarchy. Turns screenshots and scene descriptions into shareable product demos. ## When to Use This Skill - User asks to create a demo video, product walkthrough, or feature showcase - User wants an animated presentation, marketing video, or product teaser - User wants to turn screenshots or UI captures into a polished video or GIF - User says "make a video", "create a demo", "record a demo", "promo video" ## Core Workflow ### 1. Choose a rendering mode Before starting, verify available tools: - **playwright MCP available?** — needed for automated screenshots. Fallback: ask user to screenshot the HTML files manually. - **edge-tts available?** — needed for narration audio. Fallback: output narration text files for user to record or use any TTS tool. - **ffmpeg available?** — needed for compositing. Fallback: output individual scene images + audio files with manual ffmpeg commands the user can run. If none are available, produce HTML scene files + `scenes.json` manifest + narration scripts. The user can composite manually or use any video editor. | Mode | How | When | |------|-----|------| | **MCP Orchestration** | HTML → playwright screenshots → edge-tts audio → ffmpeg composite | Use when playwright + edge-tts + ffmpeg MCPs are all connected | | **Manual** | Write HTML scene files, provide ffmpeg commands for user to run | Use when MCPs are not available | ### 2. Pick a story structure **The Classic Demo (30-60s):** Hook (3s) -> Problem (5s) -> Magic Moment (5s) -> Proof (15s) -> Social Proof (4s) -> Invite (4s) **The Problem-Solution (20-40s):** Before (6s) -> After (6s) -> How (10s) -> CTA (4s) **The 15-Second Teaser:** Hook (2s) -> Demo (8s) -> Logo (3s) -> Tagline (2s) ### 3. Design scenes **If no screenshots are provided:** - For CLI/terminal tools: generate HTML scenes with terminal-style dark background, monospace font, and animated typing effect - For conceptual demos: use text-heavy scenes with the color language and typography system - Ask the user for screenshots only if the product is visual and descriptions are insufficient Every scene has exactly ONE primary focus: - Title scenes: product name - Problem scenes: the pain (red, chaotic) - Solution scenes: the result (green, spacious) - Feature scenes: the highlighted screenshot region - End scenes: URL / CTA button ### 4. Write narration - One idea per scene. If you need "and" you need two scenes. - Lead with the verb. "Organize your tabs" not "Tab organization is provided." - No jargon. "Your tabs organize themselves" not "AI-powered tab categorization." - Use contrast. "24 tabs. One click. 5 groups." ## Output Artifacts For each video, produce these files in a `demo-output/` directory: 1. `scenes/` — one HTML file per scene (1920x1080 viewport) 2. `narration/` — one `.txt` file per scene (for edge-tts input) 3. `scenes.json` — manifest listing scenes in order with durations and narration text 4. `build.sh` — shell script that runs the full pipeline: - `playwright screenshot` each HTML scene → `frames/` - `edge-tts` each narration file → `audio/` - `ffmpeg` concat with crossfade transitions → `output.mp4` If MCPs are unavailable, still produce items 1-3. Include the ffmpeg commands in `build.sh` for the user to run manually. ## Scene Design System See [references/scene-design-system.md](references/scene-design-system.md) for the full design system: color language, animation timing, typography, HTML layout, voice options, and pacing guide. ## Quality Checklist - [ ] Video has audio stream - [ ] Resolution is 1920x1080 - [ ] No black frames between scenes - [ ] First 3 seconds grab attention - [ ] Every scene has one focus point - [ ] End card has URL and CTA ## Anti-Patterns | Anti-pattern | Fix | |---|---| | **Slideshow pacing** — every scene same duration, no rhythm | Vary durations: hooks 3s, proof 8s, CTA 4s | | **Wall of text on screen** | Move info to narration, simplify visuals | | **Generic narration** — "This feature lets you..." | Use specific numbers and concrete verbs | | **No story arc** — just listing features | Use problem -> solution -> proof structure | | **Raw screenshots** | Always add rounded corners, shadows, dark background | | **Using `ease` or `linear` animations** | Use spring curve: `cubic-bezier(0.16, 1, 0.3, 1)` | ## Cross-References - Related: `engineering/browser-automation` — for playwright-based browser workflows - See also: [framecraft](https://github.com/vaddisrinivas/framecraft) — open-source scene rendering pipeline --- ## Why This Skill Exists Implement — <!-- SR_40: auto-generated from frontmatter `purpose`/`description` (OPP-Phase3). Expand with domain-specific rationale. --> ## What If Fails If this skill fails to produce the expected output: (1) verify input completeness, (2) retry with more specific context, (3) fall back to the parent workflow without this skill. <!-- SR_40: auto-generated from frontmatter `what_if_fails` (OPP-Phase3). -->