How does DVD Shrink differentiate between main movie and extras

[Chetwood]

Since dvdshrink is still out of the loop and ppl here have extensive knowledge of the DVD structure I thought I'd ask here rather than in the 1-click forum. I've always been wondering how DVD Shrink knows which title of the DVD belongs to extras and which is the main movie. I'm quite certain it can't be size alone since there's also DVDs with really short main movies which are still recognized as such. Any ideas?

[jeanl]

I think I read somewhere that it's based on the number of chapters...
jeanl

[sweetness]

i'm not 100% sure. i put a episodes dvd, and title 1-3 where the main movie. all are in the same title set(which is the biggest in size). All titles are around the same size and time with the same number of chapters.

So i made a little blank dvd. one title with two PGC. one had 4 chapters and the other 24. dvdshrink recognized the one with 24 chapters as the main movie [Title 1 (continued)] and the other one as extras [Title 1].

then i made another dvd with two titlesets(each titleset was the same as above) and now shrink has both title 1 and title 2 as the main movie(the ones with the most chapters) with the other titles as extras.

hope i'm making sense.

so all in all, it would probable look at size, time, and number of chapters.
that's my guess.

EDIT: man i have to learn to type faster. :p

[blutach]

I'm pretty sure it is size. I blanked everything in the DVD and it reported ALL the titles as main movie. As you can see, title 11 was it (it had 30 odd chapters of 1/2 second each).

http://img227.echo.cx/img227/6784/untitled7xj.png (http://www.imageshack.us)

Regards