How to tell if a stream have been transcoded

[GZZ]

I have been asked alot of times from people, if its possible to make some program that scan the DVD stream and maybe compare it to the original DVD, to tell if a Transcoder or a real encoder (like CCE) have been used...

Is it possible to code somekind of program that can scan the main movie stream or any other part of the DVD to tell if a transcoder have been used or not.

I know that you sometimes can read the application ID, implementation ID, the Provider ID and so on, but they don't allways tell truth and can be change afterwards.

I have been thinking if you can count the number of I, P, B picture in the stream to tell if transcoder have been used or not?.. But I'm not really sure or maybe there are NO way to tell ?

GZZ

[int 21h]

The I, P, & B pictures will remain constant.

[GZZ]

so there is no other way to tell ?

GZZ