A general architecture of video codec for real time communication at 64 kbit/s

摘要

In the field of videocoding high computational power is needed to perform special functions such as movement detection, DCT, quantisation, Huffman coding and decoding, etc. A DSP-based parallel architecture can efficiently realize a moving image communication system operating at low bit rate, without using specialized hardware: the main advantage of this approach is that it allows to change easily the coding algorithms, by simply modifying the software which controls the system, so that the same equipment can be used to realize different codecs.The flexibility of this solution was exploited in designing a video codec able to act as a moving image communication system for inter-personal communication, with sufficient spatial resolution for moving images, or as a still picture transmission system, working at full CCIR resolution, which gives a good image quality in a rather short time (5–6 s) for several applications such as device monitoring, photography or document transmission, etc.