DVDShrink, what do I lose ?

[vcd_user]

I am new to DVD authoring. I had problem writing DL DVD using my DL DVD writer. Also DL DVD media are more expensive. So I always use DVD Shrink to shrink DVDs bigger than 4.7G so that I can make a bakup on a 4.7G DVD media ? I know that I probably lose some quality because of the smaller amount of data storing on the DVD. As I am a beginner, I am just using full bakup on DVD Shrink without changing any parameters. What do I really lose when I shrink using DVD shrink ? What parameter should I start to play with if I don't want to lose too much sound quality and willing to sacrifice picture quality ?

[samijubal]

You won't lose audio quality, it doesn't compress audio. Take out any extras you don't need like foreign langauge tracks. For the best video quality, use deep analysis and AEC (adaptive error compensation). It takes a lot longer, but the results are definitely better.

[handyguy]

Its depends on what kind of tv you watch it. Most of the time you won't notice much. Have you watched divx? They compress a 4 gig to a cd & look extremely decent.

[MOVIEGEEK]

My rule is:if I have to compress >35% I split to two DVD's(no compression) or use a DL.I get my DVDR's for ~$.33 a piece so it's no big deal and it takes 5 minutes to split.

[redwudz]

It depends on how much you shrink and how particular you are. I like to keep them in the 70% or higher area. If it would end up lower, I dump all the extras and second languages, subtitles, and anything I can live without. I can always put them on a second disc. And you can use deep analysis to make the most of the higher shrinkage.

For DL backups, use a program like DVD Decrypter to burn. ISO read> ISO write. And Verbatim DL discs seem to be the most problem free.

[Recca421]

I personally never shrink, I always split DVD9 to 2 (or more) DVD+/-R.

It uses a lot of discs, but I've never really been satisfied with the quality of the transcoded files. Others migh be, but *I* notice the quality loss.

My other reason for doing this is that I'm not a fan of complicated, animated, useless menus. I'd much rather re-author with useful, clean, compact menus that actually work. This also allows me to strip extras and Easter Eggs to their own discs with ease.

The downside to this, of course, is that a 2xDVD-9 set can take 4 or 5 disks to back up.

When i want to fit more than one movie on a did I generally accept the quality loss and drop to 352x480 - fit 2 to 3 movies per DVD+/-R using this method.

[slimpickins]

unless u have a 42"plus plasma or lcd screen then u wont notice any major quality loss, if u have got a 42" plasma or lcd then i suggest u buy a dvd up-converter (they come standard with hd and blu-ray players) the upconverter will make more of a difference than the compression rates,

a commercial dvd is never really full and also the extras take up a bit so if u only copy the movie and menu u will be fine,

i dont like 2 split it into 2 disc cos it sems pointless, especially if use printable dvd's

the only thing id consider splitting into 2 dvd's are tv epsisode disks that have 4 45min eps on 1 disk, but i dont think u can split those

[vcd_user]

Thanks for the quick responses. I am watching DVD on a regular TV. I had not noticed any major reduction of picture quality when watch my single disk backup. I was concern about the audio quality which one of the responses said the audio is not affected. I'll be quite happy with the single DVD backup until I have money for the plasma.

[jtoolman2000]

I really enjoy listening to people that claim to see the diference in even slightly compressed copies. REALLY???? I have a top of the line DLP 52 TV fully calibrated and most movies that are top quality transfers to begin with look great even when I compress to 70%. Deep analysis and error compensation helps as well.

Yes, less than 70% and you can see some compression artifacts but for most flicks it's acceptable. What original movie really looks GREAT on the original disk anyway? Not many. There are some excellent movie or digital to disk transfers but until Hollywood realizes or decides that the movie is ultimately what we want and not stupid extras they seem so insistant to cram, maybe the overall original quality will increase.

The higher the original quality, the more compression you will be able to get away with with minimal apparent loss.

Besides if you really want it at its best, go to DL media.

Lately, I don't back up that mich anyway, only the accassional DVD I purchase as I have everything already on my library backed up and I f I really want to see the extras I dust off the original.

[fritzi93]

What you lose is some of the DCT coefficient data, that's how a transcoder works.
If you really want to know, look here:

http://forum.doom9.org/showthread.php?&threadid=63587

Not much use to a novice, though, is it? Simple answer: To retain the maximum quality when backing-up to single-layer, do movie only and de-select all but one audio stream. Do a whole disc backup and the quality will inevitably suffer. Or compromise in some areas, selectively discarding unwanted bits with something like VobBlanker.

But, as already stated, you have to decide what's acceptable to you.

[Recca421]

What original movie really looks GREAT on the original disk anyway? Not many. There are some excellent movie or digital to disk transfers but until Hollywood realizes or decides that the movie is ultimately what we want and not stupid extras they seem so insistant to cram, maybe the overall original quality will increase.

It's not the ones that do look good, or are at least transferred well, that I am concerned with backing up in this fashion. It's the ones that don't look that great to start with (low bitrate transfers etc), or where the menus are so poorly authored (or overly bloated) as to be un-navigable (Rammstein's "Lichtspeilhaus" DVD springs to mind).

[slimpickins]

i say just accept what u get and just foccus on switching to high defintion

[ROF]

Since you are backing up something which is obviously important and there is vital data contained within this backup which requires you to back it up you might as well invest a few bucks in media which doesn't compromise the quality of the backed up data.

In other words, Dual Layer media is quite cheap when you realize that you are backing up something important to you.

I never use shrink. At even 10% compression you can start seeing a visual difference in your backup which defeats the entire purpose of backing up.

Of course, there will always be those who have a different tolerance for compressed backups. Some people even claim that MP3 audio when recorded at a high bit rate sounds just as good as an original.

[slimpickins]

i have so many dvd's i can nbever worry about just 1, id just back it up again if i was that concerned, dual layer is out of the question, and splitting into 2 discs is a possibility but that would lead to loads of other problems

my plan is if the dvd looks fine on my eventual big gd tv then thats great but if not ill find the best tv to display averagely backed up dvds, e.g my 28 crt never sees the difference of backed up dvd's so if i can get maybe a 42crt that also doesnt show the difference then im fine with having 2 tv's

[slimpickins]

to confirm, the film dr strangelove that i made a complete backup with, (over 90mins of extras) so probably well over 200mins of video, it was totally unwatchable on my 19inch lcd computer screen but on my 28inch crt it is completely watchable so ill cross my fingers that it is totally watchable on a 42"crt, one of those rear projectiopn tv's