Key Technology Research On Avs-based IPTV

IPTV is a brand new technology providing a variety of interactive digital multimedia services including digital television to home users through broadband network. It has gradually been adopted by operators in many countries and deployed in large. Since IPTV is bring into Chinese Mainland, with the joint effort, the Chinese IPTV market has seen significant development, and the majority of provinces and cities have launched the domestic IPTV service. In 2009, the number of IPTV users in Chinese Mainland reached 4.7 million, and continued to grow steadily.AVS standard, the second-generation source coding standard of China with independent intellectual property rights, established as an open standard basing on our innovative technologies and open techniques with technical program profile, high efficiency and low royalties, is very suitable for the IPTV system in China. Nowadays, China's major telecom operators are experimentally using AVS standard in their IPTV network.The main research object of this paper is IPTV system based on AVS Standard. IPTV system is a complex system, and the core of the frame typically includes encoding and decoding systems, content distribution, storage, authentication and accounting systems, digital copyright protection system and user terminals and some other. This article focuses on the client and digital rights protection. For these two parts, this paper mainly discusses the AVS decoder optimization in user terminal and digital watermarking technology in video for copyright protection. The main research content and innovation are as follows:1. Reviewing the IPTV historical development and the present situation, we have analyzed the IPTV system's core frame and the key technologies, and elaborated the user terminal system and the digital copyright protective system's key technologies emphatically: the AVS decoder optimization techniques and the research present situation of the digital video watermark technology . Simultaneously I have introduced the main feature of the AVS video standard, as well as the superiority compared with other standards including H.264.2. We have proposed an ACP optimization method for the AVS video decoder. From the algorithm, the code, the platform, we optimized the AVS video decoder in three aspects in ensuring the video decoding quality, effectively improving the decoder's decoding speed.3. We have proposed one invisible digital watermark algorithm based on the movement vector. This algorithm makes full use of the correlation between the macro block, which makes the watermark embedding rule simple and effective. Experimental results indicate that after applying the algorithm by embedding the watermark, the video peak value signal-to-noise radio loses slightly, and the watermark embedding quantity is big. The extraction algorithm has the blind measuring ability, which can auto-adapted extract the watermark precisely.4. We have proposed a partial decoding and then encoding visible video watermark embedding plan. By the way I frame and P,B frames should be taken a different embedding strategy, the algorithm carries on embedding and eliminating operation in the affected area, which can embeds visible watermark in the AVS video stream in real-time(for example station logo and so on).This method brings smaller loss to the original video, and can achieve real-time watermark embedding.