A Minimal Peer to Peer One to One Video Call

Am implementation of a simple 1-1 Video Calling Web App

Technologies Used:

• NodeJS : For Signalling Server and Web Backend
• WebRTC : To implement the Video Call Part

Working of the App

Room Object

Defines a Room Object used in the server side where two peers can join to start a Video Call. 

• Integer : room_id
• Integer : max number of Users
• JSON(Peer ID : Peer)

Peer Object

Defines a Peer Object in the server to save the details of a Peer for further use. 

• String : Peer Name
• String : Peer ID
• Socket : Peer Connection Object

Frontend

On GET '/' :

• Create New Room : Lets user create a Room ID and join one. 
  • Generate Random number => Room ID (Must be unique)
  • Go to '/r/room_id/'
• Join Existing Room : Lets a user join an existing room created by another peer. 
  • Enter Room ID
  • Go to '/r/room_id/'

On GET '/r/room_id/' :

• Get Room ID from window.location.href
• Take a Name as input for Peer
• Get User Media for Demo display
• Create Socket Connection on Global NameSpace
• Can Show existing members of the room
• On Join :
  • Emit 'join' message with room_id and peer_name
  • Get User Media for Local Stream and Local Video
  • Create RTCPeerConnection
  • Listen to Signalling Server :
    • 'user-arrived' : Create Offer and Send
    • 'offer' : Add Remote SDP to self and Create Answer and Send
    • 'answer' : Add Remote SDP to self and Start sedning streams
    • 'cut-the-call' : Close RTCPeerConnection and MediaStream and redirect to main page

Backend

• Create Express App
• Create a Socket to listen

Server Requests :

• '/' : Render index.html
• '/r/:room_id/' :
  • If Room Exists : Render videocall.html ? Render index.html

Socket Messages :

• 'create-room' :
  • If Empty Room with that Room ID exists : return the URL for that room
  • Else :
    • Create Room and on No error : return the URL for that room
    • If error : Ask to create again
• 'join' :
  • If Room is Empty :
    • Create Peer Obj and Add socket to Room
  • Else If Room Not Empty
    • If has Space :
      • Create Peer Obj and Add socket to Room
      • Broadcast to other users in the room 'user-arrived' with peer_id
    • Else
      • Emit 'full-room'
• 'offer' :
  • Emit to added user the Offer
• 'answer :
  • Emit to added user the Answer
• 'cut-the-call' :
  • Remove Peer Obj and delete socket from the room