The Key Technologies Of AVS Real-time Encoder (D1) Under SOA Architecture

AVS is the second generation digital audio and video coding standard with independent intellectual property of our own country.The coding efficiency of AVS is more than twice as MPEG-2 and the same as the international standard-H.264. AVS video part is a series of highly efficient new technologies, including the operations based on the smallest data's pieces of 8x8, symmetric mode of B-frame prediction method, integer DCT, quantization,2D-VLC entropy coding and inter prediction based on multiple reference frames. While the lower cost of AVS standard patent, but the high computational complexity in the code does restrict the application and promotion of the AVS encoder, making no mature Dl format AVS video encoder. This paper uses TIs embedded video system chip TMS320DM6446 as a platform to complete the Dl format AVS real-time encoder. The main research contents and results are as follows:First, this paper uses three-tier architecture of SO A to analyze AVS encoder, and details the atomic component sets of AVS Jizhun Profile. In the semantic layer, it defines a set of language, using which can be formal description of AVS coding process. Then, the paper takes full advantage of VLIW and SIMD, as much as possible to write efficient assembly codes. All key modules of AVS encoder are written in assembly code, the optimizations are obvious. The real-time realization of P-frame code, we use parallel program of DSP and VICP, using VICP to complete the residual, DCT, quantization, inverse quantization, IDCT, reconstruction and find cbp operation, greatly enhancing the P-Frame code optimization efficiency. Reasonable distribute CACHE memory to improve CACHE hit rates and use DMA by using technologies such as ping-pong buffer for data transmission, which improve the efficiency of the coding module.Finally, combine AVS encoder and the SIP protocol, built into a network video surveillance system which can be real-time encoded.The coding frame rate of I-frame of the final implementation of AVS encoder in the format of Dl reached 32 fps, while the coding frame rate of P-frame reached 24 fps, basically meet the real-time requirements. The network video surveillance system can work well.