In view of recent developments in use of video signals in computer networks, mobile, video conferencing etc, digital transmission and storage of digital signals have become very important issues. In that regard different video standards have been proposed for compression of video information, in different rates, and for different applications. Optimization and design of new algorithms for implementation of these standards have attracted a lot of attention from researchers and engineers interested in such issues. In this thesis, after introducing some of important video compression standards, the main blocks of video codec structures and new algorithms for computing and implementation of them are discussed. To that end, after brief reviewing of color spaces and picture and video formats, discrete cosine transform (DCT) as a main block in video codecs, and it’s properties and implementation algorithms are reviewed in details. also, quantization, entropy coding, motion estimation and compensation are discussed. At the end, after introducing a sample video source coder, that can be used in many standards, its operation in bit-level is explained and related simulation results are presented. The Sample video source coder is implemented on Xilinx FPGA’s and results are presented.