Technical Summary
Several MIME type/subtype combinations exist that can contain
different media formats. A receiving agent thus needs to examine the
details of such media content to determine if the specific elements
can be rendered given an available set of codecs. Especially when
the end system has limited resources, or the connection to the end
system has limited bandwidth, it is helpful to know from the Content-
Type alone if the content can be rendered.
This document specifies two parameters, "codecs" and "profiles",
which are used with various MIME types or type/subtype combinations
to allow for unambiguous specification of the codecs and/or profiles
employed by the media formats contained within. This document
obsoletes RFC 4281; RFC 4281 defines the "codecs" parameter, which
this document retains in a backwards compatible manner with minor
clarifications; the "profiles" parameter is added by this document.
Working Group Summary
This document is not the product of a WG. It was reviewed by the
Apps Review Team and got external review in MPEG DASH, the
MPEG file format group, 3GPP SA4 and its equivalent 3GPP2 group,
internal review by the Quicktime team at Apple, and comments from
the MPEG21 chair.
Document Quality
The MPEG DASH spec relies on this mechanism, but there are no
known implementations to date.
Personnel
Pete Resnick <presnick@qualcomm.com> is shepherd and AD.