how to convert mp4 format video files to other formats like .ogg and .webm to run in all browsers during upload using php and jquery. And is there any solution to use encode one format to other formats according to browser's need so that it will occupy less space on server.
If you want to have multiple files to use with HTML5 for browser compatibility, use FFMpeg to do the conversions on file upload.
If you want to just use one mp4 file and have a flash fallback for all browsers, I would recommend MediaElement.js.