AddPac D1 video codecs like as AP-NC600, AP-NC500 are DSP based next generation high performance 1~2 channel D1 video encoder devices which has compact chassis. It is applicable to various real time fields, for instance, surveillance, traffic management, and environment surveillance. AddPac D1 video codecs are designed to support outstanding stability and high quality video transmission and provide various features to meet changing market needs by leveraging the programmable high performance DSP. These market-ready video encoder/decoder systems enable realization of complete IP based video network surveillance and security solution targeting for cost effective high-quality hardware type network cameras. AddPac D1 video codecs provide the video encoding solution over various WAN environments such as xDSL, cable TV and internet leased line. AddPac D1 video codec are RTSP based standard compliant and interoperates efficiently with video solutions from other vendors as well as pre-existing video solutions from AddPac, such as the network DVR solution.