Hi Rajat, > I have been going through the project ideas of the *openCast*, and I > came across the idea of *Variable Playback Speed**. *However I have > some doubts regarding the project. Such as how are we going to reduce > the time of the playback. Are we going to increase the speed of the > playback (which I don't believe is the idea), or are we going to > remove some part of video from the original file ? Can anyone help > me. Or does anyone know how to contact the mentor.
There are two ways to do this, either increase the speed of playback, or compress playback by removing uninteresting parts of the video (called "video skims"). Either of these methods are interesting to me as a feature, but require a different background. Increasing the speed of playback would require investigating gstreamer, specifically how gstreamer can read and write to file descriptors in order to hook it up with the SOX project to pitch shift audio so it doesn't sound too "chipmonky". Fairly minimal java code would need to be written for this integration, and the majority of code would need to be gstreamer related with a little UI work to show alternate videos. Creating video skims is much more involved, but a much less naive approach to speeding up playback. You can think of video skims as similar to lossy compression for video, where duplicate frames or frames of video that aren't important are removed. e.g. when an instructor has written something on the board and hasn't said anything because he is waiting for students to transcribe it, you can delete some seconds video. You could imagine some parameters to creating skims to determine how aggressive they might be (e.g. ignore one video feed over another, ignore audio, etc.). Of course, both approaches could be used together as well, to create a lossy high speed playback. I'm willing to mentor this project, but it does require a fair amount of self study and self interest. It's not by any means a trivial project, and would probably require hanging out in #gstreamer and asking alot of questions. A background in gstreamer would be great. Feel free to drop me a question if you have any more thoughts, Chris -- Christopher Brooks, BSc, MSc ARIES Laboratory, University of Saskatchewan Web: http://www.cs.usask.ca/~cab938 Phone: 1.306.966.1442 Mail: Advanced Research in Intelligent Educational Systems Laboratory Department of Computer Science University of Saskatchewan 176 Thorvaldson Building 110 Science Place Saskatoon, SK S7N 5C9 _______________________________________________ Community mailing list [email protected] http://lists.opencastproject.org/mailman/listinfo/community To unsubscribe please email [email protected] _______________________________________________
