The only app to translate RM and RMVB files in Mac OSX.
Interface is a bit unusual (eg. no mention of mp4). One has to choose "optimize" and then the option "PSP".
I got good results with all my RMVB files. Indeed, the colors and contrast got BETTER in the encoded mp4 than in the initial .RMVB file.
However, the speed of the .mp4 was excessive (about 15%). Some fine tuning may be necessary using the rather cryptic options of the optimize menu.
The app also works on incomplete films but it sticks to the original length of the film => one has to wait until the missing part is also encoded. Alternatively, one can interrupt the encoding at the right moment. In this latter case, I found that only Mplayer OSX extended could read the file ( = no further editing possible).