The Audio-visual Profile with Feedback (AVPF) specification defines a
framework and messages for fast feedback and media control over RTCP.
The Codec Control Messages (CCM) specification defines an extension
to AVPF, by specifying additional messages for codec control and
feedback. This specification extends CCM, by specifying messages
that let participants dynamically communicate a set of codec
configuration parameters, which enables better optimization of
resource efficiency and quality of media transmission.