Fusion Embedded™ SDP
Session Description Protocol
The Fusion Embedded™ SDP software stack provides functions to parse Session Description Protocol (SDP) announcements into convenient C structures and to build SDP announcements using the same C structures as inputs. The parser is specifically targeted at parsing SDP announcements for the RTP/AVP transport with media formats using the numerical payload types. The parser is ideally suited for use in mainstream applications such as VoIP.
SDP is a text-based protocol used to describe multi-media sessions. It is a general-purpose protocol designed for use in a range of applications from Voice over IP (VoIP) to ad-hoc multicast conferences. A description of a multi-media session is termed an “announcement” or SDP announcement.
Fusion SDP RFC Compliance and Features
- RFC 2327 (SDP: Session Description Protocol)
- RFC 3264 (An Offer/Answer Model with the Session Description)
Protocol (SDP)
- RFC 3551 (RTP Profile for Audio and Video Conferences with Minimal Control)
- Per RFC 2327 Parses and builds all fields, including complex multicast
connection fields, complex time fields with repeat times and zone adjustments,
etc.
- Unlike text-only SDP parsers, the parser converts strings representing numbers
such as RTP port numbers, bandwidths, etc. into numerical values. Likewise, the
builder converts numerical values into strings.
- The toolkit groups together logically associated fields into a single C structure.
For example, the “rtpmap” and “fmtp” attributes found in media-descriptions are grouped together with the corresponding format from the media-field format list providing logical coherence for these fields. - Provides both high-level API calls that can parse/build and entire SDP announcement, and provides low-level functions for parsing/building individual fields of SDP announcements
- 100% ANSI C using porting macros for all system dependencies (C runtime functions etc.) for the ultimate in portability
- Simple architecture makes it easy to enhance as required to support new extensions to SDP as they arise
