Settings View Source WebRTC Endpoint

The WebRTC Endpoint is responsible for sending/receiving media tracks to/from a web borwser.

architecture

Architecture

tracksender

TrackSender

TrackSender is responsible for observing track activity and publishing track data to the engine. In particular, it is responsible for sending Membrane.RTC.Engine.Event.TrackVariantResumed and Membrane.RTC.Engine.Event.TrackVariantPaused events, and replying to Membrane.KeyframeRequestEvent.

VariantTracker

A browser can pause sending some encoding when e.g. it doesn't have enough bandwidth. This fact is not communicated to the server. VariantTracker is responsible for tracking variant activity i.e. whether it is still active.

trackreceiver

TrackReceiver

TrackReceiver is responsible for receiving a track from the engine. In particular, it is responsible for sending the Membrane.RTC.Engine.Event.RequestTrackVariant event, forwarding keyframe requests from the browser to the TrackSender and repairing RTP packets after switching track variants.

connectionallocator

ConnectionAllocator

ConnectionAllocator is responsible for probing the connection and negotiating bandwidth with TrackReceiver. The RTC Engine ships with two implementations of ConnectionAllocator:

• Membrane.RTC.Engine.Endpoint.WebRTC.NoOpConnectionAllocator - always grants bandwidth requested by TrackReceiver
• Membrane.RTC.Engine.Endpoint.WebRTC.RTPConnectionAllocator - probes the connection with RTP padding packets and grants bandwidth basing on GCC estimates

You can read more in Membrane.RTC.Engine.Endpoint.WebRTC.ConnectionAllocator module docs.