DGIndex vs. DGIndexNV

[Marin85]

Hi,

I am wondering about the following thing. From what I gather, DGIndex is intended for work only with MPEG-1/2 streams, while DGIndexNV is intended for usage with H.264 streams. In this regard, I have the following questions:

1) Can DGIndexNV also be used for MPEG-1/MPEG-2 streams? And, similarly, can DGIndex be used for H.264 streams? Can any of these be used for VC-1 streams as well?

2) In case both tools are complimentary, should both DGDecode.dll and DGDecodeNV.dll be placed in the Avisynth folder or does DGDecodeNV also cover the functionality of DGDecode (assuming suitable nVidia card installed)? Is DGSource() then automagically associated with the correct .dll, depending on the nature of the source?

Thanks in advance for any input!