Hello, currently ffmpeg2theora-0.24 requires either <ffmpeg-9999[vhook] or >=ffmpeg-9999. This is wrong now, because ffmpeg-0.5_p19787 suppors vhook no longer and it is not needed to build ffmpeg2theora now. That's why dependency should be corrected to check vhook flag for pre 0.5_p19787 versions.
Created attachment 203388 [details, diff] ebuild update
Already did that yesterday