Research And Implementation Of The Avs And Mpeg-2 Video Transcoding

Digital videos are ideal vehicles for the dissemination of information at the multimedia age,but the huge mass of video data need to be coded for efficient transmission and processing. For different application areas, industrial communities and international organizations for standardization have developed a variety of video coding standards. Of these standards, MPEG-2, drawn up by ISO/IEC, has got widely used in our country and has been the preferred encoding format in many areas such as digital TV, DVD store, and studio editing. In contrast, as one of the second-generation video coding standards, AVS was developed by our country with independent intellectual property rights. It has higher coding efficiency and avoids expensive international patent costs of MPEG-2, so it can be used to replace MPEG-2 in many relevant areas. On the one hand, with the transcoding of existing MPEG-2 videos to AVS, the technological advantages of AVS can be fully used. On the other hand, with the transcoding of AVS videos to MPEG-2, the existing video terminal equipments will not be wasted. Therefore, the study of video transcoding between MPEG-2 and AVS is of great significance.Firstly, the video transcoding technology and research at home and abroad are briefly introduced in this dissertation, and the main research content and main tasks are also described meanwhile. Secondly, the relevant theoretical bases are outlined, focusing on transcoding architecture and key technologies. On the former, three typical architectures are analyzed, comparing their respective advantages and disadvantages. On the latter, three key technologies, combined with research issues in this dissertation, are analyzed, including MV reuse, MVR and MB mode mapping. Thirdly, through the comparative analysis of their technical characteristics, video stream structure and decoding process, the MPEG-2 and AVS standards are studied and their main differences are proposed. In this way, the general idea of transcoding between these standards is proposed, giving out the clue of the following tasks. Finally, the fast video transcoding schemes between MPEG-2 and AVS are proposed and so the MPEG-2-to-AVS and AVS-to-MPEG-2 transcoding softwares are designed and implemented. According to the test results, it has been proved that these schemes may greatly improve the efficiency of transcoding than traditional CPDT while maintaining video quality to meet the needs of subjective visual.