AIcut Video Editing Skill

This skill helps understand and manipulate the AIcut video editing system.

Core Concepts

Project Structure

• •Project Snapshot: ai_workspace/project-snapshot.json - The single source of truth for timeline state.
• •Project Folders: projects/<display-name>/ - Readable folder names mapped to internal IDs via projects/projectIdMap.json.
• •Assets: projects/<display-name>/assets/ - Media files organized by type.
• •Exports: exports/ - Final rendered videos.

Project Management

1. UI Creation & Management

• •Create: Click "New Project" in the /projects page.
• •View: Browse existing projects in the UI list. The UI synchronizes with the filesystem in real-time.
• •Delete: Click the Delete icon on a project card. This removes the project from the UI and deletes its folder from the projects/ directory.

2. Programmatic Lifecycle (New/Switch/Delete Project Logic)

To manage projects via API/Python:

1. •Initialize: Call switch_project(projectId). If the project is loaded for the first time, it creates the folder. If it exists, the UI will automatically jump to that project.
2. •Archiving (Readable Folders): Use archive_project(). The system uses the project's name as the folder name.
3. •Switching: Call switch_project(anotherId). The UI will perform a hot-reload and navigate to the new project editor.
4. •Mapping: Folder names are mapped to internal IDs in projectIdMap.json.
5. •Deletion: Call delete_project(projectId) to permanently remove the project folder and its ID mapping.

Element Types

1. Media Element (Video/Image/Audio)

{
  "id": "e.g., el-0",
  "type": "media",
  "mediaId": "asset-reference-id",
  "name": "display-name.mp4",
  "thumbnailUrl": "/api/media/serve?path=...", // CRITICAL for video/image preview
  "startTime": 0.0,      // In seconds
  "duration": 5.0,       // Visible duration
  "trimStart": 0.0,      // Crop from start of source
  "trimEnd": 0.0,        // Crop from end of source
  "x": 960, "y": 540,    // Postion (Center origin is 960, 540)
  "scale": 1.0, 
  "opacity": 1.0,
  "volume": 1.0,
  "metadata": {
    "importSource": "sdk_v2" 
  }
}

2. Text/Subtitle Element

To ensure compatibility between Python and Frontend, use this format:

{
  "id": "unique-id",
  "type": "text",
  "content": "The display text",    // Primary text field
  "startTime": 0.0,
  "duration": 3.0,
  "trimStart": 0, "trimEnd": 0,    // MUST include (default to 0)
  "x": 960, "y": 900,              // Subtitle position (bottom center)
  "rotation": 0, "opacity": 1,     // MUST include defaults
  "fontSize": 60,                  // Styles MUST be at top level
  "fontFamily": "Arial",           
  "color": "#ffffff",
  "textAlign": "center",
  "fontWeight": "bold",
  "style": {                       // Optional nested style for Python SDK
     "fontSize": 60,
     "color": "#ffffff"
  }
}

Data Schema Rules (The "Contract")

1. •Primary Text Field: Use content as the single source of truth for text. The name field is OMITTED for text elements to prevent redundancy.
2. •Flattened Styles: While Python SDK uses a style object, the frontend requires fontSize, color, etc., at the top level of the element.
3. •Implicit Defaults: Never skip trimStart, trimEnd, rotation, and opacity. If missing, the frontend might fail to render or default to 0 (invisible).
4. •Coordinate System: origin (0,0) is Top-Left. 1920x1080 canvas. Standard center is (960, 540).
5. •IDs: IDs must be unique strings (e.g., nanoid or sub-0, sub-1).

Common Operations

Adding Media

Preferred Method: Use AIcut SDK (import_media). The SDK automates the following steps:

1. •Thumbnail Generation: Calls /api/media/generate-thumbnail for videos to create high-quality frames.
2. •Asset Creation: Automatically calculates IDs and creates an asset entry with a stable serve URL.
3. •Element Placement: Adds the element to the timeline with the correct thumbnailUrl.

Manual Method (Advanced):

1. •Create an asset entry in the assets array.
2. •Create an element in a track referencing the asset's id.
3. •MUST set thumbnailUrl (use the asset's URL or a dedicated JPG thumb) for visual feedback.

Creating Subtitles

1. •Create or use an existing text track (type: text).
2. •Add text elements according to the Text Element Schema above.
3. •Synchronize startTime with audio assets.

Modifying Volume

• •Set element.volume (0.0 = mute, 1.0 = normal, up to 10.0 = 1000%).

API Integration

The frontend exposes a state-syncing API at POST /api/ai-edit. Always prefer using the Python SDK (scripts/aicut_sdk.py) over raw HTTP requests.

Supported Actions (POST)

Media Utilities

• •GET /api/media/serve?path=<encoded_absolute_path>: Serves local files as browser-accessible URLs.
• •POST /api/media/generate-thumbnail: Generate a JPG from a video file (Body: { filePath: string }).

Snapshot & Project Endpoints

• •GET /api/ai-edit?action=getSnapshot: Retrieve current timeline state.
• •GET /api/ai-edit?action=listProjects: List all archived projects.
• •GET /api/ai-edit?action=poll: Polled by frontend to fetch pending edits.

Best Practices

1. •Avoid curl on Windows: Use a temporary Python script or the AIcut SDK for stable JSON communication.
2. •Paths: DO NOT use /materials/ relative paths. Always use absolute paths wrapped in the /api/media/serve?path= API. This ensures files from any drive (F:, D:, etc.) work correctly.
3. •Atomic Updates: Read the full snapshot, modify your slice, then write the full snapshot back.
4. •Validation: Ensure all numeric fields are number type, not string.
5. •Layering: Text tracks should remain at the top (lower array index) to be visible over media.
6. •SDK First: Always use scripts/aicut_sdk.py. It correctly handles thumbnail generation calls and internal path mapping.

Executable Scripts

The following scripts/CLIs are available in the scripts/ directory:

Note: These scripts depend on scripts/aicut_sdk.py. Ensure you run them from the skill directory or add the directory to your PYTHONPATH.