Undoing DVDShrink compression?

[lonwa]

Ok, here is my question.

I just tested out one of my backups using DVDShrink on a Front projector = 60 inch, and obviously the quality is noticeably poorer than on my 27 Inch. The original looks fine on the FP.

So, my question to you guys is, when say dual layered DVD-Rs become available, or some new technology that allows us to burn more stuff per media, how do I go about reversing the compression DVDShrink performed on my backup?

Maybe its not possible, but my understanding is that DVDShrink just performs another level of compression, so in theory, we should be able to uncompress back to the original, just like we do with WinZIP or WinRAR right?

Thanks for any help in this matter

Lonwa

[Kedirekin]

Undoing the compression is easy. Throw the DVDShrink backup in the trash and create a new backup from the original.

Seriously though, there is no way to undo the compression. MPG is a lossy codec. What DVDShrink (and the other transcoders) do is to increase the quantization of the MPG stream. In other words, it makes the stream *more* lossy.

Unlike WinZip (which uses a lossless compression scheme) it is not possible to undo lossy compression; the information to do so has been lost.

[scharfis_brain]

DVDshrink is a LOSSY transcoder/compressor.
That means that you cannot undo the losses (blocky- and blurryness) introduced by DVDshrink.

[lonwa]

Thanks for the quick replys. Is there a non-lossy program available today for compressing dvds?

Thanks


Jeff

[Kedirekin]

Nope - at least not one that will do anything. You could certainly run the files off a DVD through WinZip or WinRAR, but the compressed files would hardly be any smaller - they might even be bigger.

And I wouldn't hold my breath waiting either. I don't like to say anything is impossible, but someone inventing a way to losslessly compress MPG to half its size is so extremely unlikely, it might as well be impossible.

[lonwa]

thanks, one last question, although its a little off topic.

is the MP3 format also lossy?


Lonwa

[gooki]

Yes it is.