Technical Summary
This document describes a Frame Marking RTP header extension used to
convey information about video frames that is critical for error
recovery and packet forwarding in RTP middleboxes or network nodes.
It is most useful when media is encrypted, and essential when the
middlebox or node has no access to the media decryption keys. It is
also useful for codec-agnostic processing of encrypted or unencrypted
media, while it also supports extensions for codec-specific
information.
Working Group Summary
This document has been under development for quite some time, the
first version having been published in 2015; this is why its draft
name refers to the AVTExt working group, which was merged back into
AVTCore in 2017.
There have been multiple WGLCs carried out in the AVTCore working
group, which gave thorough review to the document.
Document Quality
The specification was implemented for some time in libwebrtc and
deployed in Google Chrome's WebRTC stack; however, Chrome later
removed support for it, as its applicability seemed to be limited.
The document has been reviewed by WG members, and appears to be
complete insofar as it goes; however, there are concerns that it is
not sufficient for the uses cases for which it was intended.
Notably, the significantly more complex AV1 Dependency Descriptor
[https://aomediacodec.github.io/av1-rtp-spec/#appendix] addresses a
similar use-case much more thoroughly.
Personnel
The document shepherd is Jonathan Lennox; the responsible area
director is Murray Kucherawy.