RTCP XR Block Type for inter-destination media synchronization
This document specifies an RTCP XR Block Type for inter-destination media synchronization (IDMS). The RTCP Block Type is used to collect information on media play-out time of a specific RTP media stream, and to distribute a summary of the collected information. This information can be used to synchronize the play-out of media such as audio, video and/or subtitles among multiple devices. This document also specifies the associated SDP parameter. The SDP parameter is used to signal the use of the RTCP XR block for inter- destination media synchronization. Typical applications for inter-destination media synchronization are social TV, watching apart together and shared service control. Each of these applications has two or more geographically separated users watching a media stream on respective devices. RTCP-XR is intended as a signaling mechanism to enable various media synchronization algorithms amongst users. The presented RTCP-XR specification for IDMS is independent of the used synchronization algorithm.