Study element based adaptation of lecture videos to mobile devices

With devices like mobile phones and PDAs becoming pervasive especially among students, there is a demand for viewing lecture videos on such devices, to get quick access to educational content. But, being traditionally designed for desktop computers, lecture videos have high video bit-rates, due to which viewing them on low network bandwidth connections like GPRS incurs long delays and high costs. In this paper, we propose a novel method for adapting lecture videos, to make them viewable on low bandwidth connections, at low cost. Our idea is to exploit redundancy present in lecture videos, such as non-changing presentation slides. We define study-elements within the video that have varying levels of redundancy and user-expectations. We send images at different intervals, such as one image every five seconds, according to the Study-Element involved along with continuous audio. In our experiments, we have found that for a video of size 432MB, our method achieved 97% reduction in size, that was better than that achieved by standard codecs for that video. Additionally, our method can be customized according to the level of user experience desired.