Compression and quality with DVD Shrink

[AlucardXXVII]

I've been backing up some movies with DVD Shrink and I have had to use compression on a handful of them. I really can't tell any difference in the quality either.

My question, though: I want to start backing up the entire DVD, not just the movie, but that will obviously make me have to use more compression. At what point in the compression scale should I start to notice a difference in the quality? I think Star Wars Empire Strikes back needed 82% just for the movie and I didn't see or hear any noticeable quality loss.

So basically, how far can I compress a movie and still be safe to not see any difference in the picture?

I also want to know because I want to put a bunch of south park episodes onto one disc and those are already crappy quality.

[NickSaunders]

That is a very subjective question. There is no one answer. It depends on a number of things including compressibility of the source, size of your TV and viewing distance from it along with what looks acceptable to you. It is a very personal decision. What I think looks good you may think sucks.

You can always do a movie only (with menus) with DVDShrink and VOB Blanker, and a second one with menus and extras.

[jimmalenko]

Nick nailed it - home run!

- How often do you watch the extras ? (could you survive by using your originals when you want to watch the extras)
- Is splitting to 2 discs, or using DL media worth considering ?

There's no true answer unfortunately. I find any compression is fine, but that's just my experience on a 27" TV. You really need to try a couple for yourself and find your own acceptable compression level, or try the alternatives I've listed above.

[AlucardXXVII]

does otpw mean Off Topic Post Whore?

Also, thanks guys

[jimmalenko]

does otpw mean Off Topic Post Whore?

Also, thanks guys

Yes.

[shelbyGT]

Yes, too subjective of a question.
Personally, on long movies (troy, LOTR, King Arthur, etc) I prefer to split to two discs (or, if I ever get a DL burner, use that).

Personal preference. On the other hand, I backed up my CSI discs using about 60% compression on all of them and for the most part they look just like a normal TV broadcast. So see? it differs.

[videsiboy]

It is acceptable upto 60% for me. If it goes less than that, I split it into two DVDs.

If there are fast movements (action sequences) in the movie, even at 60% I observed some distortion (grains).

I always do deep analysis before shrinking.

[Gurm]

You just have to play with it. My PERSONAL rule is that I don't accept anything below 75% for an action flick, or anything below 65% for a slower movie - but then again, I only have a 27" TV in the living room and it's only running S-Video. On my friend's 32" with component, I can already see that some of the backups I make aren't the greatest.

If it's something I think there's a good chance I'll actually LOSE the original (something I'm backing up because it's scratched or getting worn out) I tend to run DVD Rebuilder, or else do a movie-only backup in order to preserve quality.

But everyone is different.

[RickTheRed]

So basically, how far can I compress a movie and still be safe to not see any difference in the picture?

Like Nick said, if the source is high quality video, you can compress alot. If the source is average, split it. It will get worse.

Rules of thumb: from 75 to 80%, it should be fine with deep analysis and AEC set at sharp. For lower compression setting, select a "tough" scene of 30 sec and run three small tests. The first one is the original, another one is compressed using aec at max smooth and finally, the last one is compressed with either sharp or max sharp.
With dvdshrink, you add the three files in reauthor mode, and you play them in full screen mode.
From that, you should be able to select the right method (aec smooth, sharp, extra smooth, or split the disc).

I've done the first two harry potter (both were between 55 and 60%) and I was not able to see something on a 19" crt monitor.

I also want to know because I want to put a bunch of south park episodes onto one disc and those are already crappy quality.

If they are already crap quality, you may not want to shrink it more, it may become ugly to watch.