In Local Environment my application was running smoothly without any issues, but when i deployed it on EC2, I was getting the error querying device -1 error while i was trying to send streaming audio data to the backend via a WebSocket.

  useEffect(() => {
    socketRef.current = new WebSocket('ws://3.6.39.130:8000/ws');
    
    socketRef.current.onopen = () => {
        console.log('WebSocket connected');
    };

    socketRef.current.onmessage = (event) => {
        const data = JSON.parse(event.data);
        console.log('Received transcription:', data.transcript);
        // Update UI or state with transcription data
    };

    socketRef.current.onclose = () => {
        console.log('WebSocket connection closed');
    };

    socketRef.current.onerror = (error) => {
        console.error('WebSocket error:', error);
    };

    return () => {
        // Clean up WebSocket connection on component unmount
        if (socketRef.current) {
            socketRef.current.close();
        }
    };
}, []);

const startRecording = () => {
  navigator.mediaDevices.getUserMedia({ audio: true })
      .then((stream) => {
          // Start WebSocket communication
          socketRef.current.send(JSON.stringify({ action: 'start' }));
          
          // Process audio stream chunks and send to WebSocket
          const mediaRecorder = new MediaRecorder(stream);
          mediaRecorder.ondataavailable = (event) => {
              if (event.data.size > 0) {
                  socketRef.current.send(event.data);
              }
          };
          mediaRecorder.start();
      })
      .catch((error) => {
          console.error('Error accessing microphone:', error);
      });
};

const stopRecording = () => {
  // Stop MediaRecorder and WebSocket communication
  if (mediaRecorder.state === 'recording') {
      mediaRecorder.stop();
  }
  socketRef.current.send(JSON.stringify({ action: 'stop' }));
};

I have used mediaRecorder to get audio from user’s Browser. Also tried to get the necessary permissions from the user to access the microphone.

//fastapi endpoint

@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    stop_event = asyncio.Event()
    try:
        while True:
            data = await websocket.receive_json()
            if data['action'] == 'start':
                print("Starting transcription...")
                stop_event.clear()
                asyncio.create_task(transcribe(stop_event))
            elif data['action'] == 'stop':
                print("Stopping transcription...")
                stop_event.set()
    except WebSocketDisconnect:
        print("WebSocket disconnected")
        stop_event.set()