Whoops. Sorry to bring “bad news”, ..
.. sad to here since ffmpeg isn't really a replacement for mencoder, since it:
a. doesn't support DVD and BD Input
b. has no chapter and title support (for DVD/BD and files with chapters)
c. doesn't have usable filters for deinterlacing and filtering (no ivtc, denoise,...)
d. can't decoder formats through vfw and qt filters (i.e. AppleProRes, 10bit DNxHD,..)
anyways: Thanks for the heads up.
BTW, it looks like FFmpeg will get 10-bit H.264 support very soon (decoding already seems to work).
Whooo, nice, 10bit decoding would be cool, since then one could finally use x264 10bit encoding without having to buy the mainconcept decoder. (which is a bit pricey for private only use)