# Demo Video > Create scripted terminal demo videos of Hermes Agent using the screenplay YAML pipeline. Record, render, and composite polished MP4s with camera zoom/pan, skin theming, and background compositing. - Skill: `peteromallet/demo-video` (Agent Skill, multi-file: 5 files) - Install (CLI): `npx skillmds@latest add peteromallet/demo-video` - Raw SKILL.md: https://api.skillmd.com/api/skills/peteromallet/demo-video/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: DevOps & Infra - License: MIT - Author: peteromallet (https://skillmd.com/u/peteromallet) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/peteromallet/demo-video --- # Demo Video Pipeline Create polished terminal demo videos from YAML screenplays. The pipeline records a scripted terminal session, renders it to GIF via agg, then composites to MP4 with camera zoom/pan effects. ## Prerequisites - `asciinema` — terminal session recording - `agg` — asciinema GIF renderer ([github.com/asciinema/agg](https://github.com/asciinema/agg)) - `ffmpeg` — video encoding - Python packages: `pillow`, `numpy`, `pyyaml`, `pydantic` ## Quick Start ```bash # Preview in terminal (no recording) python -m demo demo/scripts/example.yaml # Record and render to MP4 python -m demo demo/scripts/example.yaml -o demo.mp4 # With a specific skin python -m demo demo/scripts/example.yaml -o demo.mp4 --skin ares # Dry run (print commands without executing) python -m demo demo/scripts/example.yaml -o demo.mp4 --dry-run ``` ## Verify your font setup before authoring Skins use Braille, dingbats, and box-drawing glyphs that not every monospace font covers. Before authoring a screenplay or picking a custom `font_family` / `skin`, run: ``` python -m moirae fonts test ``` This renders a 5-second smoke clip exercising every glyph category the built-in skins reach for. Inspect the result for tofu boxes (□ with ?). If any glyph is broken, swap the font or skin before you spend minutes on a full render. ``` python -m moirae fonts test --font "Menlo" # check a specific font python -m moirae fonts test --skin ares # check a specific skin's glyphs ``` For a quick preview of a real screenplay's first few seconds (avoids waiting for a full render to spot layout issues): ``` python -m moirae preview my-screenplay.yaml --duration 8 ``` ## CLI Options | Flag | Description | |------|-------------| | `script` | Path to YAML screenplay file (required) | | `-o, --output PATH` | Output MP4 path. If omitted, defaults to `--play` mode | | `--play` | Preview in terminal without recording | | `--skin NAME` | Override skin (e.g. `ares`, `mono`, `slate`, `poseidon`) | | `--typing-speed FLOAT` | Override typing speed (seconds per character) | | `--dry-run` | Print pipeline commands without executing | | `--debug-camera` | Print resolved camera keyframe timeline | ## Screenplay YAML Schema ```yaml title: "My Demo" skin: "default" # Skin name (default, ares, mono, slate, poseidon, sisyphus, charizard) typing_speed: 0.04 # Seconds per character pause_between: 1.0 # Default pause between scenes output: width: 2560 # Render resolution (2x for sharp text) height: 1440 final_width: 1280 # Output resolution final_height: 720 fps: 30 font_size: 22 font_family: "Menlo" theme: "github-light" # agg theme override (omit to use skin default) bg_image: "path/to/bg.jpg" # Background image (optional) bg_color: "#fdf1de" # Background fill color (optional) bg_opacity: 0.85 # Terminal opacity over background (0.0–1.0) terminal_cols: 200 # Terminal grid width (>= 80, <= 400) terminal_rows: 120 # Terminal grid height (>= 40, <= 500) scenes: # ... scene list (see Scene Types below) ``` ### Terminal grid sizing `output.terminal_rows` controls how tall the underlying asciinema buffer is. The default is 120 rows — enough for ~5–10 Q+A exchanges before older content scrolls off the top. If your screenplay has many scenes, bump `terminal_rows` so the conversation doesn't overflow the buffer (each Q+A is roughly 12–15 rows). Hitting the buffer top causes the terminal to scroll, which pins the auto-tracking camera at the bottom of the visible viewport. `terminal_cols` defaults to 200; widen it only if a single line of content needs more horizontal room than the default. ### Theme and Skin Interaction The terminal rendering theme comes from the skin's `terminal_theme` field by default. All built-in skins use `github-light`. To override for a specific video, set `output.theme` in the YAML — this takes precedence over the skin. The compositor's background detection color is derived automatically from the theme via `AGG_THEME_BG` in `skin_engine.py`. Available agg themes: `asciinema`, `dracula`, `github-dark`, `github-light`, `kanagawa`, `kanagawa-dragon`, `kanagawa-light`, `monokai`, `nord`, `solarized-dark`, `solarized-light`, `gruvbox-dark`. ## Scene Types ### Action Scenes ```yaml # Clear terminal - action: clear # Type a shell command with output - action: type_command prefix: "~ $ " command: "hermes" output: "Starting Hermes Agent..." # optional # Show the agent banner - action: banner model: "deephermes-3-llama-3.1-8b" context: "128K" session_id: "d8f2a1c4" tools_count: 24 skills_count: 42 # Pause - action: pause duration: 1.5 # Print styled text - action: print text: "Hello world" color: "#FFD700" # Standalone camera move - action: camera zoom: 1.0 duration: 0.8 ease: "ease-out" ``` ### Conversation Scenes ```yaml - user: "What are the latest developments in AI agents?" thinking_time: 3.5 typing_speed: 0.03 # override per-scene pre_pause: 0.5 post_pause: 0.5 tools: - icon: "🔍" verb: "search" detail: '"AI agents 2026"' duration: "2.1s" delay: 0.3 response: | Here are the key developments... response_label: " ⚕ Hermes " # Camera directives (optional) camera: zoom: 1.8 x: 0.5 # Normalized 0.0–1.0 y: 0.15 at: "user_start" # Timing marker duration: 0.8 ease: "ease-in-out" camera_response: zoom: 1.4 y: 0.65 at: "response_start" duration: 0.5 ease: "ease-in-out" ``` ### Camera Directives Camera directives control zoom and pan during the video. They can be: - Attached to conversation scenes (`camera:` and `camera_response:`) - Standalone action scenes (`action: camera`) | Field | Default | Description | |-------|---------|-------------| | `zoom` | 1.0 | Zoom multiplier (1.0 = full frame, 2.0 = 2x zoom) | | `x` | 0.5 | Horizontal center (0.0 = left, 1.0 = right) | | `y` | 0.5 | Vertical center (0.0 = top, 1.0 = bottom) | | `auto_y` | false | Compute y from cursor position at marker time | | `at` | "scene_start" | Timing marker (`user_start`, `response_start`, `scene_start`) | | `duration` | 0.5 | Transition time in seconds | | `ease` | "ease-in-out" | Easing: `linear`, `ease-in`, `ease-out`, `ease-in-out` | ## Pipeline Stages 1. **Record** — `asciinema rec` runs the player in `--play` mode inside a PTY 2. **Render** — `agg` converts the `.cast` recording to a high-res GIF 3. **Composite** — Python reads GIF frames, applies camera crop per-frame, blends background, pipes to `ffmpeg` for MP4 encoding ## Example Screenplays - `demo/scripts/example.yaml` — Basic conversation demo - `demo/scripts/example_with_camera.yaml` — Camera zoom/pan effects - `demo/scripts/hermes_capabilities.yaml` — Full production demo with background image ## Key Files | File | Role | |------|------| | `demo/__main__.py` | CLI entry point | | `demo/schema.py` | Pydantic models for screenplay YAML | | `demo/player.py` | Terminal playback engine | | `demo/pipeline.py` | Orchestrates record → render → composite | | `demo/recorder.py` | asciinema + agg subprocess wrappers | | `demo/compositor.py` | GIF frame reader, camera crop, ffmpeg encoding | | `demo/camera.py` | Keyframe resolution and interpolation | | `demo/scenes/` | Scene handlers (conversation, action) | ## Adding text overlays to the rendered video Moirae itself doesn't composite captions or a wordmark onto the finished MP4. To do that, run the rendered output through ArtAgents' timeline + Remotion compositor — see the **"Adding overlays to a rendered video"** section in `~/Documents/reigh-workspace/ArtAgents/SKILL.md`.