Backup strategy: Better to 'Shrink' or DivX?

[beagley]

I've searched the forums but can't find a discussion on this.

I'm new to backing up DVDs. I've got a DivX DVD player, so I could either go the 'Shrink' route or the MPEG4 route.
Which is likely to give the best quality?

I can imagine the answer depends on a number of factors, so assume the following: I'd shrink to a single-sided DVD and would be prepared to do the same for MPEG4 (unless that's overkill); ignore problematic and unusually long DVDs; I'd only want to keep one audio track (surround sound if available) and I don't need to keep sub-titles.

Any advice greatfully received.

[Teegedeck]

1) Do you want to play the result on your current hardware-player? In that case I wouldn't go for MPEG-4.

The following suggests that best quality really is your top priority:
2) If you have to shrink your movie by only, say, 10% I'd go for, well, 'Shrink' or Instant Copy.
3) If 10% won't do, you have the option of either recompressing with, say, CCE or QuEnc (both together with DVD-Rebuilder) to MPEG-2 or with XviD to MPEG-4. IF your movie compresses, again: say, with QuEnc and the QLB-matrix at quantizer=2 to a size you can burn, then both options are alright:
XviD would be smaller, QuEnc or CCE would be faster.
4) If QuEnc+QLB @quant=2 produces too big a file, XviD would seem preferable - if you have a fast PC, are willing to learn some not-so-easy procedures and have p a t i e n c e. XviD at full anamorphic resolution with best-quality options enabled is not exactly fast.
From my experience XviD can rival best CCE quality (i.e. it can produce a copy which cannot be told from the original = 'transparency'), at half or less the size CCE produces.

In all, I cannot recommend this for you at the moment. If you stay around, you might find it more entertaining to use XviD than to use Shrink or CCE, but if you are ready to spend one DVD-R per movie, Shrink or DVD-Rebuilder+CCE/Quenc seems your best option.

Edit:
Try and find out where Shrink starts to look worse than QuEnc to you yourself; that is subjective and 10% compression are not an absolute value. With a noisy source you might find even 30% Instant Copy results more true to the original than QuEnc or CCE results.