LuxASR Live

How It Works

LuxASR Live uses WebSocket streaming to send audio from your browser to our speech recognition server in real-time. The audio is processed using Voice Activity Detection (VAD) to intelligently segment speech, then transcribed using our state-of-the-art Luxembourgish ASR model.

Features

• Real-time transcription – See results as you speak
• Voice Activity Detection – Intelligent audio segmentation
• Multiple languages – Luxembourgish, English, French, German, Spanish, Portuguese
• Low latency – Optimized for responsive transcription
• Download support – Save your transcriptions as text files

Technical Details

• Audio format: 16-bit PCM, 16kHz mono
• Chunk duration: 1-30 seconds (adaptive based on speech activity)
• Silence detection: Automatically sends audio after 1.5 seconds of silence
• Protocol: WebSocket with binary audio and JSON control messages
• Backend: FastAPI + Uvicorn (async I/O optimized)

WebSocket API

Connect to the WebSocket endpoint for programmatic access:

wss://luxasr.uni.lu/ws/transcribe

Client → Server:

• Binary frames: 16-bit PCM audio samples
• JSON: {"type": "config", "language": "lb"} – Set language
• JSON: {"type": "stop"} – End session and process remaining audio
• JSON: {"type": "clear"} – Clear accumulated transcription

Server → Client:

• {"type": "connected", "session_id": "...", "config": {...}}
• {"type": "transcription", "text": "...", "accumulated_text": "...", "segment": 1, "metrics": {...}}
• {"type": "error", "error": "..."}

REST Endpoints

• GET /live/health – Health check
• GET /live/config – Current configuration
• GET /live/sessions – Active sessions

Privacy & Data

Audio is streamed directly to our server at the University of Luxembourg and processed in real-time. No audio or transcription data is stored after the session ends. All processing stays within the University's network infrastructure in Luxembourg.

Browser Requirements

LuxASR Live requires a modern browser with WebSocket and Web Audio API support. Recommended browsers: Chrome, Firefox, Safari, Edge (latest versions).