DVD Shrink v3.2b3 comparative tests

Thanks again, Sophocles, if "No Compression" did actually modify the video stream that would have skewed my comparison tests.

 

Who made the statement? It would skew all of our results. In high compression on large movies the video gets soft but lower the compression then better the results
_X_X_X_X_X_[small]

"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]

 

A member of the Digital Video Forums. I can't recall his/her username.

 

Thanks for the confirmation, vurbal, I appreciate it.

 

vurbal, if it's not too much to ask, could you repeat the same test, this time switching DVD Shrink to "Custom Ratio: 100%"?

 

This sounds very interesting indeed, and could be very useful to dvdshrink (if he's not already using it).
In any case I'd very much appreciate if you could give me more details about SSIM - where to get it, a few pointers on how to use it to make comparisons...

P.S: thanks for running the test.
_X_X_X_X_X_[small]~ ddlooping~
For DVD Shrink and related softwares guides and downloads, please visit http://www.dvdshrink.info[/small]

 

Ok, I know this may not seem fair to some, but I've decided to give Vurbal access to the betas if he wants it.
He seems to be very knowledgeable, and his comparison method could be very useful for DVD Shrink development.

So Vurbal, would you be interested, and would you have the time to do some testing?

Edit: I was writing this post while you were posting your reply, Vurbal.
Thanks for the information and detailed explanation.
The offer still stands.
_X_X_X_X_X_[small]~ ddlooping~
For DVD Shrink and related softwares guides and downloads, please visit http://www.dvdshrink.info[/small]

 

I don't know what level of compression was used in your test, but v3.1.7 used to try and compress the I-frames as a last resort.
This could in turn create the effect you described (affectionaly known as pumping").
v3.2 new quality settings/compression algorithms work in a different way and should hopefully minimise this effect by spreading the compression in a different manner.

 

Done.
Off to bed now. See you all if a few hours.

 

I have a little bit of information to add to the discussion about contrast output by DVD Shrink. My methods may not be as scientific as those of vurbal, but they were done in a manner which tried to eliminate any bias. Before I get jumped, the bias of testing, I'm not talking about personal bias.

P4, 2.8GHz, 1GB RAM, 2WD HDs-330GB, ATI 9800 Radeon card, Memorex Dual Format 4X DVD Recorder, Win XP, DVD Shrink 3.2b4 Beta, DVD Decrypter 3.2.3.0, Nero ShowTime player and WinDVD Platinum 6 player software, 20" color monitor, Samsung DVD Player with S-Video to 60" rear projection TV (with more bells and whistles). Just a little of the setup so one can get a picture of the equipment in use.

[bold]I noticed a slight variation in contrast that varied from the original and from a file ripped with DVD Decrypter.[/bold] It was a slight variation but noticable to the naked eye. It is most noticable with light and colors. The shift might not be noticable against dark backgrounds or with subdued cinematography techniques, i.e. The Godfather. In movies with sunny outdoor scenes, The Pirates of the Caribbean, The Gladiator, and Lord of the Rings: Return of the King , one can see the difference. It is not a problem. I would say more of an idiosyncracy. The picture is just a little less sharp and the colors just a bit subdued. I have heard the term 'softened' used to describe the phenomenon.

I ripped 2 files with DVD Shrink, 1 at 100%, the other set at No Compression. Those 2 appeared identical. I ripped 1 file using DVD Decrypter. The original DVD was used to show the clip segment as well. I used a family member for a subject due to accessability on short notice (come here a few minutes). I used a blind setup so the viewer could not see which clips were being shown. I used the opening of the slave/gladiator sale scene in The Gladiator; sunlight, vivid color and sharp cinematography. I played 2 minutes from each file and the original disc. The subject chose the original and DVD Decrypter file as appearing the same, with the 2 DVD Shrink files appearing the same. The difference was described as the original and Decrypter files being sharper and the colors more vivid. DVD Shrink files were described as being just a little less sharp and the colors a little dull. The files were shuffled so the 2 Shrink files were mixed between the original and the Decrypter file. The test was repeated twice and the order of the clips changed. In both cases the DVD Shrink files were noted to be 'soft'. The clips were played through both the Nero Showtime and WinDVD 6 Platinum player software.
All clips were burned using CMC Magnetics +R media and the Nero 6 Burning ROM. BTW, no problems with the media. It may go south down the road, but at present is good. The soft effect was more noticable on the big screen. The order of the clips had been changed again and the two Shrink files were again described as 'soft'. The Shrink clips produced a good video, just a slight variation in contrast.

 

Thanks for this detailed report, brobear.

I do not doubt the unbiased nature of your test, neither the efficiency or thoroughness of your comparison method, but I still have to experience the "softening" effect (or any other effect) you describe when using "No Compression".
This leaves me extremely puzzled.

I hope others will be able to shade some light on this matter.
dvdshrink, for one, has always maintain "No Compression" would leave the video stream untouched.

P.S: is it something you've also experienced with other transcoders - DVD2One, IC8, Nero Recode DVDCopy...?

 

When I used the Shrink beta to transcode the movie The Gladiator, I used deep analysis and checked the boxes in Quality Settings. I removed one audio file from the Full Disc backup. The files were 6915MB and the compression level was at 57.1% (compressed 42.9%). The software worked well even under this high compression level.

I got a good picture with none of the compression woes attributed to the earlier versions of DVD Shrink. All in all, Mr Shrink has done an excellent job of improving his software to work well with higher compression loads. The deep analysis and quality settings produce a video as good as the current Shrink at low or no compression. Recording time was just over 2 hours. I give this program a big thumbs up. Well done.

 

Thanks for the positive feedback, it's very much appreciated.

 

dvdshrink is lurking on the Digital Video Forums as we speak, and has been informed of your experience.
Hopefully he will respond to it, and I'll then relay his reply (as I do not think he's an Afterdawn member).

 

ddlooping
I don't have IC8 and don't use DVD2One enough to really comment. I used DVD X Copy Platinum for a while, Clone DVD2, DVDCopy2, and Recode2. I never noticed this anomaly with these. You act as though this is earth shattering. I noted this is minor and let me add, almost trivial; but it is there. If I was the only person to ever see it, then I would wonder.

An interesting side note. The program DVDCopy2 actually enhances the contrast of a copied movie. Some of the backups are actually sharper and brighter than the original. Go figure.