Implementation and quality evaluation of video telephony using Session Initiation Protocol

摘要

Video telephony is a big change of communication technologies and becomes a standard-based technology available on personal computers and mobile phones for today. Video telephony technology has been developed using several advanced technologies which can be simplified into two fundamental parts, i.e., server and client. The server enables the clients to keep connect to each other while the client captures the audio and video data for transmission and converts the transmission of data back to the form of audio and video signals. For our implemented systems, Session Initiation Protocol (SIP) server is used as video telephony server. Video codec such as VP8, MPEG4, H263, and H264 are used as video compression in the client. The performances of codec are evaluated by objective and subjective quality tests. The result shows that the implemented system can work properly and the video quality of each codec is also evaluated.