ffmpegGUI is a frontend to ffmpeg that allow you to set most important conversion parameters. Choose your preferred preset or make and save your own. Batch convert multiple videos with an html log. It automatically add a padding if necessary.
...This is a Video on Demand Web Based Application. You have to select your video listed in a web page then click for encoding in Theora format. It's use the "<video>" tag from HTML5 for streaming.