Originally Posted by dan_hin
you won't retain quality if you resize. you'll need to provide a high-quality, large (in dimensions and bitrate) file before scaling above the true size.
Bear in mind that some people watching your video may well be doing so on 24inch+ monitors. Do you really think that any video smaller than 1920x1080 is going to look great in fullscreen on that monitor?
my recommendation, if you can manage it, is to encode at full HD in h264 quicktime.then of course you have the issue of file size, bandwidth etc.
lastly, you could try encoding at different bitrates/sizes and linking them to larger screen sizes via a custom ui.
Dan