* ffmpeg was *silently* rejecting to deinterlace NTSC DV. The problem
      is generic for any video with yuv411. Seems like a trivial fix,
      but we really have to clean up all of the pix_fmt business a bit more.


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@2169 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b