DVD Shrink - rule of thumb?

[DRP]

What's the general concensus on here as to how far you can shrink a retail DVD before the reduction in quality becomes noticeable?

I've done a few now, but none has required a shrinkage to less than 84% of original size (according to DVD Shrink's GUI). I'm now faced with one that I can either shrink to 55% of original size to fit on DVD-R or burn to DVD+R9.

I'm thinking that a 55% shrinkage will definitely be noticeable even though I can't see any negative effect on any of the > 84% shrunk ones I've done so far, but 55% just sounds too radical to me.

Is there a rule of thumb that can be applied here?

[steve2713]

Only you can judge what's acceptable and what's not. Having said that, on a disc compressed to 55%, use deep analysis (always use deep analysis for that matter) and set AEC to 'max smooth'. It will take longer but the results will be much better. Try it out and judge for yourself how satisfied you are with the results, using AEC max smooth + Deep Analysis, it's certainly possible to get 'acceptable' results.

[guns1inger]

DVD Shrink is a transcoder and works by using the compression data already in the file. Depending on the quality of the original encoding, you might be able to compress it substantially before things get too ugly, while on others you won't have much head room at all. Other factors include the quality of your DVD player, and the size and quality of your TV, the quality of your eyesight, and just how much you are will to put up with. It never ceases to amaze me just how bad it can get before some people even notice.

Having said all that, my general rule (always ready to be broken, of course) is that Shrink is fine down to 90%, 89%-80% depends on the quality of the original, 80% - DVD Rebuilder with CCE. I am pretty particular about the quality of my movies, so I have been known to through DVD Rebuilder at 80 - 90% compressions.

[DRP]

Thanks for that. That's the answer I was kinda looking for. In my own mind I kinda had 80% pegged as the limit for using DVD Shrink, though up until now I didn't really have any idea what I was going to do if I really had to go below 80%

Never tried this DVD Rebuilder program before. It certainly has some glowing comments, so I better become aquainted quick smart I think. I'm not a CCE user (TMPGEnc for me), so I've tended to steer clear of CCE tools thus far, but if this DVD Rebuilder can put a friendly face on CCE it might be worth a go.

Thanks for the tip.

[gman4life]

I've used DVD Shrink to do all of the LOTR dvd's and the last one was down to around 55% and i used deep analysis and max smooth, as steve said, and it produced an un-noticeable change in qaulity for me. It did take a very long time however, around 2.5 hours, but it was worth it.

Just make sure that you drop all of the un-needed audio and languages.

DVDShrink is still the bomb for me.

[Gurm]

People will claim that 55% is unnoticeable. It really depends on what you're looking for and how critical you are.

Personally I think anything down to 75% is ok, considering my TV is only 32" and by the time I can afford a better TV, I'll be able to afford dual-layer backups. LOL.

[Shocker Milwaukee]

It all depends on the bitrate of the original.

[DRP]

It all depends on the bitrate of the original.

Bitrate of original is 5.53Mbps 720x576 PAL 25fps

[DRP]

People will claim that 55% is unnoticeable. It really depends on what you're looking for and how critical you are.

Well, sharpness and a crisp image is very important to me. I don't like the idea of going full-smooth to hide the macroblocks to get down to 55%.

considering my TV is only 32"

My god, are you kidding? That's an 81cm TV. That's friggin' HUGE. Just for the record, I tried it. I let DVD Shrink do the shrink down to 55% and it took the full 2.1/2 hrs as someone else said. I burnt it to DVD+RW and tried it on my 51cm TV. It looks (not unsurprisingly) absolutely horrible. Macroblocking everywhere all the time and a huge reduction in sharpness with furry lines around all sharp colour changes like across shoulders etc.

I was 90% sure that was going to be the case, but I tried it out anyway and so now I know. So just for benefit of everyone else let me just say, Using DVD Shrink to get down to 55%... not a good idea!

[mrswla]

I was 90% sure that was going to be the case, but I tried it out anyway and so now I know. So just for benefit of everyone else let me just say, Using DVD Shrink to get down to 55%... not a good idea!

Not always the case. Like gman4life, I also did LOTR but I did the Extended cuts. On The Return of the King, when I put both Titles together it said that it wouldn't fit on one dvd at max compression. So I set it up as a dual layer and let it re-code to my hard drive. After that was finished I re-opened the new files and then compressed that. So in the end, I think mine was finally compressed down to something like 40% or below. I have a 47 inch widescreen tv and barely noticed any differences. I was really shocked at how well it looked. I think it has everything to do with the bitrate, like Shocker Milwaukee said. The higher the original bitrate is, the more you can compress it without noticable effects. Of course there is a limit to this.

[mrswla]

Bitrate of original is 5.53Mbps 720x576 PAL 25fps

At this bitrate I wouldn't try compressing it too much.

[mrswla]

Is there a rule of thumb that can be applied here?

And to answer your original question, no there is no real rule of thumb. Just try to do everthing in your power to use the least amount of compression. And as you have already done, when in doubt as to the final quality, use dvd+-rw discs first.

[Cinemagic]

I agree that it really is a subjective decision. If you have a trained eye (such as working in the video industry), you can see differences between the original shot footage and the commercial DVD. Most people will not see a noticable difference even at 60% unless they have two TVs sitting side-by-side with a compressed DVD in one and a commercial DVD in the other. IMO, a 65% compressed DVD is just aboutnas good as a commercial VHS. Were you happy with commercial VHS tapes? The other thing to consider is that DVDR media is quite cheap. DVD dual layer is still expensive. I personally will try to keep compression at or higher than 68%. I will forego extras and do just the movie to decrease the compression. But then I've never been one for watching the extras anyway. I figure that I'll burn 98% of my DVDs on DVDR until DVD dual layer becomes more affordable. Then I'll re-burn on dual-layer if I really want. I think it's more important to burn on a high quality DVDR first and look at compression second.

If you want to really know what is best for your eye, take a DVD that will fit on a DVDR without compression, then burn the same movie at several different compression rates and see what is acceptable to you. If you don't want to go through a few DVDRs, then use a DVD-RW.

[jntaylor63]

Sorry folks, but anything less than 90 is not good in MHO.

Many of my back-ups were 85 to 70%. and thats with Movie only, 1 audio track and subs, the Deep Analysis and different Smooth Sharp settings. The looked fine on my Standard 32" TV with S-Video.

BUT.. when I moved to a 50" DLP HDTV and used the DVI input, iy looked on par with the good VHS Movie tapes.

Now, if its less than 90%, I back-up to Xvid with AutoGK. I set the file size to 3.85 gigs and get a movie that looks just as good as the DVD on my HDTV. I have gone the HTPC route and get away with this type of back-up. There are HD DivX players that can spin AVI files this size from a UDF DVD-R. (Avel Player comes to mind)

From what I have seen, the dual layer DVD+-R's aren't that great. Too much $$ per disk and iffy play back.

All in all, back-up to what best suits you. One of these days we will be able to back-up several DVD's to one HD-DVD/Blu-Ray disk and not have to go through this transcode/Encode/Conversion BS.

[Shocker Milwaukee]

Bitrate of original is 5.53Mbps 720x576 PAL 25fps

At this bitrate I wouldn't try compressing it too much.

I agree. That bitrate is a little over half what is possible for PAL DVD.

PAL

Video:
Up to 9.8 Mbps* (9800 kbps*) MPEG2 video

[gman4life]

I have a Sony Progressive Scan DVD player hooked up to my Hitachi 52" WS HDTV and it looks just like the original. My DVD is hooked up using just component cables.

Just my .02.

[DRP]

I've bought a couple of DVD+R9 discs now and am backing it up to those. Maybe down the track when I've had a chance to learn DVD Rebuilder a bit, I'll use these discs as a test to see if that could have done a better job, but I can't see DVD Shrink ever being able to get acceptable quality at the compression rates required for fitting to DVD5.

For the record, the video length on each dual layer disc is > 3hrs with 3 camera angles to choose from, so Id suggest that there isn't much headroom on the originals which is probably why they suffer so badly when trying to squeeze them further. Being a music concert as well there are lots of flashing "disco" light effects going on as well which tend to show up the macroblocks rather well.

[nickyboy4]

I have a 36" Panasonic TV, Shrink does a great job for me on many DVD's at 55%
For me 55% is about as far as you can go.

[guns1inger]

mrswla - let me get this straight. You took two disks and compressed the hell out of each of them, then put them both together and squeezed the living crap out of them a second time (transcoding, not encoding), and you can barely tell the difference ?

What does your seeing-eye dog think ?

[Deku Scrub]

For me it kinda depends on what type of movie it is.
For example, I backed up Jackass, which is just a bunch of guys going around doing stupid things, no special effects, no special sound effects.
I compressed it down to like 55% and kept all menus. The quality loss was noticable (but not as bad as I thought it would be), but I didn't really care; the quality of the film is in its humor, not visuals.

Then there are movies like Star Wars, in which case any quality loss is unacceptable for me.
I had to re author and chop off the credits for that.

[kisrum]

On LOTR at ~75% compression with a 32" digital tv and a Panasonic stand-alone, I could see some blocks in very dark areas of the picture, but I'm perfectly happy. On smaller sets it looks as good as the original. Haven't done anything under 70% yet. Old black and whites might look fine, but they're usually not long enough to need compression.

[jimmalenko]

Once and for all, there's no consensus possible .... nada, none.

Why ?

• Your viewing device (PC/TV/Projector) - think of a 15" pc monitor to a 27" TV to a 6ft projector screen.
• Different DVD's can be compressed differeing amounts, dependent upon the original bitrates used.
• Your eyesight is different to someone else's eyesight. Attention to detail, etc etc.

Now IF you could find someone with the same eyesight characteristics as yourself, the same viewing device and you just HAPPENED to be watching the same DVD, THEN you might be able to make some concensus. All you can really do is make some personal rules, but keep in mind that what you find acceptable on a 27" TV now, you may not find acceptable on that 50" plasma TV you'll buy in 3 years' time.

[MOVIEGEEK]

My general rule is if <70% split the DVD,I get SL DVDR's for <$.40US a piece so it's no big deal.
I only use Deep Analysis w/o AEC because the benefits at >70% aren't noticable...at least on my TV's.

[NiteLite]

All the factors above plus the quality of your TV. Digital or analog...quality of your DVD player, accurate picture reproduction as found at the top of the list at the DVD Benchmark test site or DVD players such as Sony that have a softer picture to start. Test away.
BTW...backing up TNG at 58 - 60% I use AEC "Sharp" and find very acceptable quality for getting four episodes on one disc. No fluctuations in quality seen. If two TVs side by side with original and copy playing maybe a noticable difference.
Using my 36" calibrated high quality analog TV may be a factor in having a good picture whereas a digital may not. Using top rated DVD players may be a factor whereas a no name brand may show a disturbing image.
So 60% is not a problem for me for episodic DVDs. (AEC sharp not smooth)