RTP/AVPF Compliant Feedback for Error Resilient Video Coding in Conversational Applications
Feedback-based error-resilient video coding relies on efficient transmission of feedback messages. The Audio-Visual Profile with Feedback (AVPF) for Real-time Transport Control Protocol (RTCP), i.e. RTP/AVPF, supports low-latency feedbacks. In this paper, a Reference Picture Selection (RPS) method using RTP/AVPF-compliant feedback is proposed. A restriction period is first derived in the codec layer based on the previously transmitted back-channel message, the RTCP reporting interval, the round-trip time, and the processing delay of the encoder. Then, a feedback message is transmitted when the restriction period is passed and an incorrectly reconstructed picture is detected.