While attempting to use ffmpeg to convert mp4 video, it appears that there's a fun little bug when attempting to use the preset files in /usr/local/share/ffmpeg in order to determine the encoding speed. However, when passing -vpre normal (or any of the other presets in the folder, this error occurs:
Unrecognized option 'directpred'
/usr/local/share/ffmpeg/libx264-normal.ffpreset: Invalid option or argument: 'directpred=3', parsed as 'directpred' = '3'
There doesn't appear to be much online, but this mentions it's been a problem with the git repository for just over a month now. Time to figure this thing out!
EDIT 01-07-2012 - I didn't find a direct solution to this error, but I believe I found a workaround. Specifying -preset instead of -vpre seems to have fixed the issue. I haven't been working on it for about a month now though, so I may be mistaken. Take with a grain of salt, but I hope it helps.