Was it transcoded or reencoded? That's the question

[Susana]

Not a simple question, but I'd like to know if there is a way to know if a DVD was transcoded (using any of the one click solutions) or reencoded (with dvdrebuilder for example), looking at the mpeg stream inside vobs. So, is there any appreciable difference between them, at bit level?.

Thanks.

[setarip_old]

Hi!

None of the "one click" programs that I know of place any identifying text anywhere in the DVD "packages" they create...

[Susana]

thank you setarip_old. jsoto, in another thread tell me something interesting to look at.

I suppose the question is directed to mpucoder, as he is the MPEG expert. But I think I can give you a trick to detect shrink, w/o looking into the MPEG video

Usually the SCR of the packs follows the sequence:
{
scr+=146;
scr_ext+=86;
if (scr_ext > 299) {scr++; scr_ext-=300;}
}

Shrink, keeps untouched the SCR of all non-video packs, so it has to "distribute" the compressed video along the file using less packs than the original.
Many times one VOBU starts with the NAV followed by a lot video packs (the second pack in the VOBU must be video, but the third can be any kind of pack). Well, in these VOBUs, a "normal" muxer (including DVD-RB) follow the sequence of 146.086 in scr, but shrink breaks the scr sequence just between the first video pack and the second video pack. It is a "dvdshrink signature"

jsoto

EDIT:
BTW, DVDRemake modifies the PROVIDER_ID in the IFO (although it could be changed after..)

[setarip_old]

Others are certainly more knowledgable than I about this. However, logic dictates that this DVD Shrink "signature" may or may not also result from any/many/some other conversion programs...