What Source a VOB is ?

[0verd0ze]

Is there is software that can check if the source is interlaced and so on ...

[unskinnyboy]

Yes and No.

There are softwares (http://neuron2.net/dgmpgdec/dgmpgdec.html) which will read the MPEG flags and tell you what they say, if the flags were correctly set while authoring the DVD. But the only true way is to check for yourself frame-by-frame.