webrtcbin: FEC is ignored when Bundle Policy is enabled
If the bundle-policy property of webrtcbin is set to anything other than none, FEC packets are never generated by the sender despite negotiation including FEC in the offer and answer. It appears that when a bundle-policy is set, the FEC encoder is never created.
A modified version of webrtctransceiver.c from the repo and a test script have been included to show the issue. The script runs three short tests which modify the code and give some useful debug info to compare the results.
The transmission rate when
fec-percentage is 100 should be roughly twice that compared to when it is 0 (in practice it's a bit less than double due to the second media stream.)
bundle-policy=max-bundle: The transmission rate is the same at 100% FEC as it is at 0%.