Merge commit '1194a410807bac3eafbeb632578b937656d273e7'

* commit '1194a410807bac3eafbeb632578b937656d273e7':
  indeo5: reject negative motion vectors

The added check is wrong and thus not merged.
A correct check already exists in avcodec.

Merged-by: Michael Niedermayer <michaelni@gmx.at>