Unused media stream
There is an unused stream opened on the peer connection. It can indicate a timing or edge case issue in the application’s logic.
Description
Unused streams are all streams (inbound or outbound) that were reported by the statistics but that never transport any media.
This can be “by design” or an issue in the application’s logic.
This happens when the application or the server negotiates “sendrecv” streams in a SDP m-line and never sends media for this stream. Eg: When connected to an SFU, the user can see the videos from all participants but another stream (unused) is ready in case the user wants to see the video of the active speaker. Here, this is by design but there can be cases when it was wrongly negotiated or the API addTransceiver() has not been used correctly by the application.
What do we do here?
We look for inbound and outbound streams where the codecId was missing meaning that these streams never carried audio or video. We report all these streams.