HP-UX Multimedia Streaming Protocols (MSP) Programmer's Guide

2 Using MSP APIs
This chapter describes how to use the Application Programming Interfaces (APIs) in
the MSP SDK.
It discusses the following topics:
• “RTP Library” (page 19)
• “RTP Call Order Sequence” (page 26)
• “RTSP Library” (page 28)
• “RTSP Call Order Sequence” (page 63)
• “SDP Library” (page 67)
• “SDP Call Order Sequence” (page 76)
RTP Library
This section describes the APIs in the RTP library.
The RTP library contains various categories of APIs, and the RTP header file includes
the relevant data structures. The following lists the types of APIs that the RTP library
contains:
• RTP session APIs
The RTP descriptor, rd, identifies the RTP session. It facilitates all the RTP
operations. It encapsulates information on data transaction and RTCP feedback.
The library provides APIs for retrieving information about members of an RTP
session, sending or receiving media data provided to the appropriate API, with
the help of rd.
The following lists the RTP session APIs:
— rtp_open
— rtp_close
• RTP data packet APIs
The RTP packet data structure begins with the mandatory fixed header to be
transmitted in an RTP packet. The optional data, such as the contributing source
information and extension header, follow this fixed header. Finally, the media
data follows this information. The APIs provided by this library require the RTP
packet in such a format. The RTP library fills in the version sequence number and
synchronization source identifier fields of the RTP header.
The following lists the RTP data packet APIs:
— rtp_send
— rtp_recv
— rtp_free_buf
RTP Library 19