Duration API

A high-performance microservice built in Rust that extracts duration information from video files, audio files, and SCORM e-learning packages. Designed for LMS platforms and e-learning tools that need fast, accurate content duration calculations.

Features

• Media duration extraction — MP4, AVI, MOV, WEBM, MKV, MP3, WAV, FLAC, OGG, AAC, WMA, M4A
• SCORM package analysis — SCORM 1.1, 1.2, 2004 (2nd/3rd/4th Edition), and cmi5
• Content time estimation — Reading time from HTML word counts (200 wpm) + quiz time (30s per question)
• Manifest parsing — Extracts typicalLearningTime and SCORM 2004 duration limits from imsmanifest.xml
• Multiple file processing — Submit batches of files and get individual + total durations
• File upload support — Both URL-based and multipart upload endpoints
• Configurable output format — HH:MM:SS, MM:SS, or HH:MM

Getting Started

Prerequisites

• Rust 1.86+ (for building from source)
• FFmpeg (ffprobe must be on PATH)
• Docker (optional, for containerized deployment)

Build from source

git clone https://github.com/joshghent/duration-api.git
cd duration-api
cargo build --release

The binary will be at target/release/durationapi.

Run the server

# Start on default port 3000
./target/release/durationapi serve

# Custom port
./target/release/durationapi serve --port 8080

Docker

A Docker image is published to GHCR on every merge to main:

docker run -d --name durationapi -p 3000:3000 ghcr.io/joshghent/duration-api:latest

Or build it yourself:

docker build -t durationapi .
docker run -d --name durationapi -p 3000:3000 durationapi

It's a standard Docker image — run it however you like.

API Reference

Health check

GET /health

{ "status": "ok" }

Extract duration from URL

POST /duration
Content-Type: application/json

Single file:

{
  "fileUrl": "https://example.com/video.mp4",
  "format": "HH:MM:SS"
}

Response:

{
  "duration": "00:03:24"
}

Multiple files:

{
  "files": [
    "https://example.com/intro.mp3",
    "https://example.com/lecture.mp4"
  ],
  "format": "HH:MM:SS"
}

Response:

{
  "duration": "00:54:12",
  "files": [
    { "file": "intro.mp3", "duration": "00:43:00" },
    { "file": "lecture.mp4", "duration": "00:11:12" }
  ],
  "warnings": []
}

SCORM package:

{
  "fileUrl": "https://example.com/course.zip"
}

Response:

{
  "duration": "00:45:30",
  "estimatedDuration": "00:52:15",
  "scormAnalysis": {
    "manifestDuration": "00:30:00",
    "wordCount": 2500,
    "quizQuestionCount": 10,
    "estimatedReadingTime": "00:12:30",
    "estimatedQuizTime": "00:05:00"
  }
}

Upload files directly

POST /duration/upload
Content-Type: multipart/form-data

Fields:

• files — One or more file uploads
• format — (optional) HH:MM:SS, MM:SS, or HH:MM

Response format is the same as the JSON endpoint.

Format options

Format	Example	Description
HH:MM:SS	01:30:45	Hours, minutes, seconds (default)
MM:SS	90:45	Total minutes and seconds
HH:MM	01:30	Hours and minutes (no seconds)

Error responses

Status	Meaning
400	Bad request / unsupported file
500	Internal server error

Errors return JSON:

{ "error": "Description of the problem" }

When processing multiple files, unsupported files don't cause the request to fail — they appear in the warnings array with a null duration.

SCORM Analysis

When a .zip file is submitted, the API treats it as a SCORM package:

1. Extracts the archive and scans for media files (video/audio)
2. Parses imsmanifest.xml for typicalLearningTime or SCORM 2004 duration limits
3. Counts words in all HTML/HTM files (used to estimate reading time at 200 words per minute)
4. Detects quiz questions in JavaScript files (patterns like AddQuestion(, new Question(, question object literals)
5. Returns both actual media duration and an estimated total duration that includes reading time and quiz time

Supported SCORM versions:

• SCORM 1.1
• SCORM 1.2
• SCORM 2004 2nd Edition
• SCORM 2004 3rd Edition
• SCORM 2004 4th Edition
• cmi5

Development

Run tests

# Install ffmpeg (required for media duration tests)
# macOS: brew install ffmpeg
# Ubuntu: sudo apt-get install ffmpeg

cargo test

Lint and format

cargo fmt
cargo clippy -- -D warnings

Project structure

src/
├── main.rs       # CLI and server setup
├── lib.rs        # Module exports
├── routes.rs     # HTTP endpoint handlers
├── duration.rs   # Core duration extraction and SCORM analysis
├── models.rs     # Request/response types
└── error.rs      # Error types and HTTP conversions
testfiles/        # Test media and SCORM packages

License

MIT