Design And Implementation Of IP Video Phone System Based On The Android Platform

In recent years, with the rapid development of the Internet and IP technology,real-time data transmitted by IP network is no longer limited to text and image, thedemand for the forms of information has grown to multimedia such as audio and video.Due to high demand, audio and video communication industry has developed rapidly. Inthis process, VoIP could not be ignored. It unifies various standards for audio and videocommunication, including signaling control protocol, media transfer protocol andmultimedia compression standard, makes the mutual communication through a variety ofdifferent terminal equipment possible, realizes the real-time transmission of signalingand media data, and lays the foundation of the video phone industrializationdevelopment.While VoIP technology is becoming more and more important, the theoreticalresearch alone is not enough, an IP-based video telephony designed for this has becomeincreasingly necessary.The IP videophone system takes Android smartphone as adevelopment platform, uses development methodology developing with integration, andtakes full advantage of existing mature technology. The Signaling part uses the Radvisionprotocol stack from Ruidi Communication Technology Development Co., Ltd, andreplaces the state machine while doing something to improve and optimize the work.Thesystem also uses the Linphone system media module which integrates audio and videocodecs library including G.711, G.722、H.263, H.264and MPEG-4, as well as the oRTPprotocol stack transmitting streaming data. Signaling module and media modules areencapsulated in the form of a library file to the Android system library layer and providedto the application framework in the Jni way. For good interactivity,the system realizes thefunctionality of a phone book, call records and user configuration.The system is tested between two Android smartphones within LAN, and the result shows that the predetermined design goals have reached with better voice quality, a smallamount of echo, smooth video, a slight flicker and good effect.