PreviewGen

PreviewGen is a microservice that generates .webm preview videos from a sequence of screenshots.

Built with:

• ElysiaJS web framework
• Bun runtime
• ffmpeg for video encoding
• sharp for image processing.

Designed for easy integration into Docker Compose environments, e.g. Kompakkt Mono.

API Reference

Generate Video

Endpoint:POST /generate-preview-video

Headers:Content-Type: application/json

Body Schema:

{
entityId: string;// Unique ID for the job/entity
screenshots: string[];// Array of base64 encoded image strings}

Example Request:

curl -X POST http://localhost:3000/generate-preview-video \
-H "Content-Type: application/json" \
-d '{ "entityId": "demo-1", "screenshots": ["data:image/png;base64,iVBORw0KGgo...", "data:image/png;base64,..."] }' --output preview.webm

Response: Returns the binary video file (Content-Type: video/webm).

Deployment

Docker Compose

services:
preview-gen:
image: ghcr.io/your-username/previewgen:latestrestart: alwaysports:
- "3000:3000"

Building from Source

# Build the image
docker build -t preview-gen .# Run the container
docker run -p 3000:3000 preview-gen

Development

Prerequisites:

• Bun
• FFmpeg (must be in your PATH)

# Install dependencies
bun install
# Run in development mode
bun run --watch src/index.ts

License

Licensed under the GNU Affero General Public License v3.0 (AGPLv3).