Lots of good information here from gmccomb but I think all you need to do for your issue is add scaling: fit to your clip properties, see below:
This will always keep the video at 16:9, so if you go fullscreen on a 4:3 monitor or on a 16:10 monitor the video will automatically be letterboxed to keep the aspect ratio.
Hope this helps
flowplayer("player", "flowplayer-3.2.2.swf", {
clip: {
scaling: 'fit'
},
This will always keep the video at 16:9, so if you go fullscreen on a 4:3 monitor or on a 16:10 monitor the video will automatically be letterboxed to keep the aspect ratio.
Hope this helps