PJSIP is a free and open source multimedia communication library written in C. PJSIP versions 2.12 and prior do not parse incoming RTCP feedback RPSI (Reference Picture Selection Indication) packet, but any app that directly uses pjmediartcpfbparserpsi() will be affected. A patch is available in the master branch of the pjsip/pjproject GitHub repository. There are currently no known workarounds.