egur look @
http://forum.doom9.org/showthread.php?t=159486 i tested with the oceanic samsung x264 encode and CoreAVC 3.0.1 and Arcsofts DXVA2 survive it
and i confirmed that they don't fallback to Software decoding either (some implementations do that after a bitstream check)
Vivan strange i tested several over ref frames clips from several x264 builds and it seems CoreCodec at least found a workaround the same as Arcsoft did, its impressive other solutions either switch to Software or error per frame areas
egur this though isn't a problem that should interest you as you don't use DXVA your decoder will not suffer from this
Cyberlinks DXVA has really to fight with this erroring out every frame with core 56 bitstreams