Coding of video over IP-based networks.

Samara Adil Elia Halagy
Dr. Nasser N. Al-Ani

Abstract: The increasing demand to incorporate video into communications services and the continuous developments in telecommunication, create a demand for finding efficient ways for compression techniques. In this research, the interframe approach is designed and implemented by Visual Basic language 6.0 with H.263, where the H.263 is the most important compression standard for video over the Internet. Many techniques have been applied for motion estimation for video compression. The motion estimation process is the most significant factor in a video compression process. In this thesis, it was proposed adaptive codec scheme of H.263 standard that allow a control system to evaluation the system performance by controlling the quantization scale for both encoder and decoder . One Time Search (OTS) is used I this work to get the best match between frames. The interframe approach selects a number of frames that will be compressed .These frames called Reference frames, the compression system depend on DCT transform, the DCT will enhance the quantizing step to get acceptable quality of video. Next stage, zigzag process is used for converting the 2-D matrix obtained from quantization stage into a serial string of quantified coefficient. To code these serial data string of coefficient, Run-length 100Mbs (LAN cards of speed) coding follow by S-shift is used to count the number of zero and non zero value coefficient .All these techniques in the encoder side are repeated but inversely in decoder side where the H.263 standard simulation to the video coder/decoder, and the objective video quality reveals that PSNR results are found acceptable. The combined results ultimately increase the computational of compression ratio of the original sample video by thirty times its original value with good video quality. System design can be used to construct the error control system from the valuation of the system results. The developed system is implemented using Visual Basic Language (ver 6.0) under Windows Xp operation systems. The system is executed using personal computer (processor Pentium4 2.4 GigaHz), and LAN cards of speed 100Mbs are used.