Abstract
With the rapid development of information society, the Internet has
become an indispensable part of a lot of people life.
The current flows through the Internet "bits" represented by the contents
of which have been gradually from the original data to real-time multimedia
data, the characteristic of them is very high demand for real-time.However,
the Internet is based on TCP/IP computer networks, the initial design of
location determines it is not suitable for real-time data transmission.Therefore,
IETF audio and video transmission work in January 1996 issued for real-time
application of real-time transmission protocol RTP/RTCP.RTP/RTCP make
Internet theoretically with the real-time ability of the business, the media
synchronization problems and meet the requirements of the multimedia
communication service, the IP telephone, network, multimedia conference,
remote network teaching and remote diagnosis, etc all have important
applications.
In this paper, combining with the characteristics of RTP/RTCP high
real-time performance, mainly for local area network (LAN), is put forward
using G729a audio data compression, data transmission using ortp library,
development of real-time voice communication system on the Linux
platform.This paper first introduces the simple application of real-time
transport protocol, RTP/RTCP protocol are analyzed in detail.Then this paper
introduces the implementation of system, mainly divided into three parts:
audio data acquisition and playback, audio data decoding and encoding and
audio packets sent and received.The last simply expounds the system
scalability and prospects in other areas.
【Keywords】 Real time audio transmission, RTP/RTCP, audio compression
