Better, more general fix for importing AVIs without codec parsers.
Better, more general fix for importing AVIs without codec parsers.

JanX2/Perian,JanX2/Perian,JanX2/Perian,MaddTheSane/perian,JanX2/Perian,MaddTheSane/perian,MaddTheSane/perian,MaddTheSane/perian,MaddTheSane/perian,MaddTheSane/perian,JanX2/Perian