摘要:
MOOCs (Massive Open Online Cours，大规模网络开放课程)的大力推广与盛行下，作为其中的主要教学方式的课程教学视频也开始备受关注。作为课堂教学和远程网络教学的一种手段，课程教学视频能够记录下比课本更丰富、更多功能的在线学习内容。由于网络速度与快速浏览的限制，学习者对课程教学视频的接受的程度有限。本文提出了具有视频索引、关键字搜索、在线字幕呈现与编辑的ICS (Indexed, Captioned and Searchable)教学视频，改善与强化用户体验。通过分析与介绍课程教学视频中高效的索引算法、运用隔帧采样与二进制搜索方法分析教学视频，利用对图片的预处理与OCR技术识别视频中的文字，使用关键字匹配来搜索与识别所需教学视频；并运用语音自动转换成文字，进行半自动化的字幕校正与呈现。ICS课程教学视频的应用，提供了更灵活的教学视频课程方式，能帮助学生在更灵活的时间、任何地方，以学生为主控角色进行更有效的学习。也为MOOCs中教学视频的发展与录制提供智慧参考。
Abstract: Under the promotion and popularization of MOOCs (Massive Open Online Courses), lecture video as one of the main teaching medium, begins to catch peoples’ attention. As a means of classroom and remote network instruction, curriculum lecture videos can record more versatile and multi-functional learning contents compared to a textbook. As the restrictions of the network speed and fast browsing, learners’ acceptable level of lecture video is limited. In this paper, ICS lecture video was introduced with technology of video indexing, keywords search, online subtitle rendering and editing, which can improve and strengthen the users’ experience. Through analysing and present-ing the effective algorithm of the indexing of lecture video, one frame per sample interval was examined and the binary searching method was used. Image pretreatment and OCR tools were used to identify the option, keywords matched to search the required index of lecture video; option of lecture video is automatically recognition to text by a semi-automatic generate processing. ICS lecture video provides a more flexible way of teaching lessons to help learners as master roles in a more flexible time, in any place, to learn effectively. Also it provides a wisdom reference for the development and recording of lecture video in MOOCs.