Jpg to FLV converter

I am looking to have an app programmed which will take a number of jpg photo files and convert them into flv video files. There also be a function for the user to watermark the files either with text that they type into the UI or a photo file they upload. There will be a place on the UI to select an input folder of jpg files. There will also be a place to select a a range of numbers (for example, 5-10) which, for each flv output, the app will select a random number of jpgs from the file to include in that output. There will also be a place to (optionally) select a file of mp3s for which one will randomly be selected for each flv output. If the audio option is enabled, then the jpgs will automatically be stretched to match the length of the audio file. If the audio is not enabled, then the user will define how long each jpg should last in the flv. The user will define how many flvs should be output and into what folder.