Study On Key Technology Of AVCHD Nonlinear Editing System

With the development of science and technology, camcorder has developed from analog to digital, from standard-definition to high-definition mode. In 2006, Sony and Panasonic jointly issued AVCHD, a new standard for high-definition camcorder. Subsequently, both of them released several AVCHD camcorders, leading the develop direction of high-definition video format for camcorder. However, very little research on AVCHD and its non-linear editing software has been done in our country. The purpose of this paper is to systematically study the AVCHD standard, and to implement of a AVCHD non-linear editing software.This system is implemented on Mac OS platform. It can easily import the material for AVCHD camcorders and accomplish some simple non-linear editing operation, such as merging and splitting, etc. With it, we are also able to preview audio and video, create top menu of various layouts, and export AVCHD data to Blu-ray disc. I this paper, the details of every modules of this system are presented, and some improved and innovative methods for editing and disc burning are proposed. Following are the main achievements:First, AVCHD is systematically introduced, and AVCHD data is divided into physical and logical layer. Afterwards, the function, structure and relationship of AVCHD files in both layers are thoroughly described.Based on the AVCHD structure, a non-linear editing method associated with "virtual editing" is proposed, with which we can easily merge and split files on logical layer without transcoding or modifying the M2TS and Clip information files.As for the function of video frame locating, in this system, we will not use the traditional method to convert all the materials to I-frame format. Instead, a new method based on the EPMap in clip information file is proposed, with which we locate the video frame in three different levels of coarse entry, fine entry and frame. This method saves the transcoding time and space consumption compared with the conventional way.The Blu-ray disc file system UDF will be introduced in the description of exporting AVCHD material to Blu-ray disc. A "burning-chain layer" is introduced, which separates user layer and physical sectors of a optical disc, allowing users to focus on formation of file system, while recording optimization is accomplished on the "burning-chain layer". This method not only improves the burning efficiency, but also solves the problem of the sequential writing of write-once discs.Finally, AVCHD non-linear editing system is summarized and some improvements are discussed.