DIVX VS. DVD RIP... THE UNANSWERED QUESTION CONTINUES...

[dausone]

Okay I have done many searches and found many topics on this subject but none were really answered...Now understand Im no rocket encoding scientist but I do have a few good months under my belt...

I have downloaded some divx movies and compared the quality to dvd rips of the same movie and when I compare these two why is it that most of the time my divx downloads look a hell of a lot better than my rips??!! I am talking about block noise all in and around the dark areas of the movie. I know some will already say that the compression of the DIVX makes the movie softer, less sharp, thereby making less noise but producting a less appealing picture right or wrong?? Well maybe thats beside the point becuase the picture looks fine and dandy for my eyes. I just want to know why encoding to DivX beforehand can seemingly improve the picture quality by reducing noise??

I want to make a note that when I encode I use CBR just because I'm lazy and want things done faster but this isnt an argument for or against CBR vs. x-pass/ CQ VBR blah blah blah ... so maybe the experts can explain this strange and frustrating problem.

[NeVeRLiFt]

Those DivX rips you got where made by certain groups.
They use Nandub.
It does 2pass SBC encoding and can make great looking 1cd DivX movies, Just as long as the movie is 2hrs or less.
SBC stands for Smart Bitrate Control.

DivX5.02 Pro can also make some very good 1cd rips, if you use the 2pass vbr encoding.

XivD can to, but I would wait on using XviD since its not even in beta yet.

You also gotta remember Microsoft has there WMV9 aka Corona coming out and Pioneer has already made a DVD set top box that supports it and we should be seeing the same for Mpeg4 anytime now.

[Dave B]

You don't say what format your "DVD Rips" are in.

VCD?, SVCD?, Resolution?, Encoder used?. I can guarantee that a home made multipass VBR SVCD encoded directly from the ripped DVD VOB files will look better than any of the DivX files on the internet.

If your home made DVD rips look worse than the downloaded DivX files then this is an issue with your encoding settings, not with the different file formats.

[dausone]

Thanks for the replies, NeVeRLiFt interesting stuff, I will have to look into that more in depth... any links you can provide would be great.

Dave B, my rips are done with Smartripper with 'normal settings' as described in Sefy's guide... I then use dvd2avi also with 'normal settings' as described in the guide as well. I encode both my Divx and Rips with TMPGEnc, XVCD, most of the time using CBR, no filters, no change in GOP, motion search is set to slow....

If it is an issue in using CBR instead of multi-pass, this leads back to my original question: why is it that my cbr divx look better than my cbr rips?

[Akai Rounin]

The Eternal Question...

Welcome, dausone!

Yes, there have been similar topics before, but I rather like the way you put forth your question. I dredged up a rather old one that ended this past January that ended up in pretty nasty shape. The responses here by NeVeRLiFt and Dave B were each pretty good. Here's my take...

I have downloaded some divx movies and compared the quality to dvd rips of the same movie and when I compare these two why is it that most of the time my divx downloads look a hell of a lot better than my rips??!!

Dave B is right, we need more information as this is rather vague... What is "the same movie" for instance? Is the DivX file the same pixel resolution as your own DVD rip? Also, what format is your own DVD rip in: VCD, XVCD, SVCD or DivX? Surely you aren't saying that the DivX file looks better than the original VOB files ripped from your DVD...? Generally, if your own DVD rip is 352x240 pixels or less and the DivX file is 640x480 to 704x576 pixels, it is pretty obvious which will look better.

I just want to know why encoding to DivX beforehand can seemingly improve the picture quality by reducing noise??

There was an extremely lengthy discussion, that I think is still going on here, where someone asked a similar question regarding ASF. He was nearly crucified by those who insist nothing is better than a direct VOB to MPEG-1 or MPEG-2 rip. This is entirely in the Eye of the Beholder however. Many are not willing to admit this when it comes to visual quality issues.

Anyway, The Answer involved the lossy compression techniques that are actually common between ASF, WMV, DivX, MPEG-1 and MPEG-2. Each file format simply implements different means of achieving lossy compression. The idea is that if you encode from a lossy source (say, DivX to MPEG-2), there is less data there (in each frame) to convert (as compared to VOB files), so your final file size will be smaller and with careful tweaking there will be little perceived loss in overall quality from the original DVD source. If done properly even an SVCD, a notoriously disc hungry format, will look very good in a single disc.

There are those who argue vehemently in the reverse, of course. They say that formats such as ASF, WMV and DivX in particular are horrendously inferior to MPEG-2 in terms of maximum possible visual clarity. They say that the lossy techniques employed by those formats leave plentiful artifacts and muddy pictures while discarding vital frame information. They say that going from DVD to DivX to MPEG-2 is not only a waste of time but that it gives terrible results in the end. They naturally say it is perfectly fine to have a single movie encoded to two or three CD-Rs (since that is about the only way you can successfully encode SVCD to their standards anyway).

They say you'd might as well learn today how to encode to SVCD because in the future DVD-R drives and media will come down in price and SVCD or other forms of MPEG-2 rips will be the standard means of backing up DVDs for years to come. They say that CD-Rs will eventually go the way of the Dodo, floppy discs and ZiP so it doesn't matter how incredibly huge their beautiful, pristine SVCD files become. DVD-R will save the day. They say there will never, EVER be a standalone DivX/DVD player so DivX is a dead end.

So did I answer your question? Heck, probably not. But at least you have something to think about.

Unta Glebin Gloutin Globin,

Akai Rounin, The Cyber Sage

[Who waits patiently to be flamed by any and all...]

[dausone]

Thanks for the welcome Akai.. those two posts were excellent, the first I got through but the second... whew, 26 pages.. im going to have to read that over the next few days!!

Anyway, the pixel resolution of my dvd rip is 720 x 480 while my divx is 640 x 480! And just to clarify I am in no way saying that the DivX file looks better than the original VOB files ripped from my DVD, that would just be rediculous! For those that say that the "lossy techniques employed by DivX leave plentiful artifacts and muddy pictures while discarding vital frame information" I guess this is all up to the eye of the beholder, but to my eye it was no big deal maybe losing a little here and there when looking at the bigger picture which was reducing those annoying noise blocks in the dark areas of my movie.

And if that means going from DVD to DivX to MPEG-2 and fitting my movie on no more than 2 cd's while reducing the amount of block noise considerably - than so be it. (possible can of worms?)

I also agree with most people on here that cd's are the way to go, I am not a fan of watching DivX movies on my computer or using tv out in the near future anyway, so I am sticking to vcd/(s)vcd for now. And I am not out to argue this issue either!! haha.

Thanks again all.

[vitualis]

The only way that going from DVD --> DivX (or any other loss encoding scheme) --> S/VCD is going to look better than DVD --> S/VCD directly is as has been pointed out... filtering.

Going to another lossy step first, you are going to loose some of the detail and this may make it easier for the MPEG-1/2 encode to handle. On the other hand, you may or may not (realistically, you will) introduce additional encoding artifacts.

The the point is, if your eyes tell you that video that has been somehow filtered first before encoding looks "better" then, you can achieve this WITHOUT going down the route of encoding to DivX first. Most MPEG encoders have a whole raft of options in terms of filtering the video. Encoding to DivX first (for the ultimate goal of getting a S/VCD) is thus not particularly logical.

Regards.

[NeVeRLiFt]

www.doom9.org

And check the guides section for the DivX guides.

I can make some beautiful 1cd rips using Nandub and DivX5.02Pro
When watched on my TV using TV-out people think there watching the DVD

And I have pleanty of 1cd DivX rips that look as good as any SVCD.
And there only 1cd. There will be DVD units out that support Mpeg4 soon maybe and Pioneer already has a DVD unit coming out that supports WMV9 aka Corona.
You guys need to stop living in the past and wake up! WMV and Mpeg4 is here to stay


http://www.microsoft.com/presspass/Press/2002/Jul02/07-15DigitaLibraryPR.asp


Pioneer’s line of DNE products, will be launched later this year as the first home theater device to include playback support for Microsoft Windows Media Video technology.


Dont forget RealVideo9 either it looks very good to.


And of course everyone here knows that VCD/SVCD can look good when you encode using 2pass vbr using CCE or TMPGEnc.

[adam]

Encoding to an intermediate format before encoding to your target format is no different than just using noise reduction. Your intentially removing detail from the picture so it will therefore compress better.

I think encoding to divx first would be equivalent to using a pretty heavy noise reduction setting. Whether or not this achieves higher quality is up to you. During bitrate intensive scenes there will be less artifacts but the whole movie will be much softer and contain less detail. If you prefer this then thats perfectly ok but its silly to bother encoding to divx first...just use a noise reduction filter.

720x480 is way to large of a resolution to use at VCD/SVCD'ish bitrates, especially when encoding in CBR. Use 480x480 instead and the quality will be much better.

Divx very well may be higher quality than (X)SVCD to your eyes, this is all really very subjective. But I hardly think you are setting up a fair comparison between the two. With more logical settings I think you will find that the quality of the (X)SVCD can be much improved.

[NeVeRLiFt]

http://www.doom9.org/codec3-2.htm

Dude where you been?

The quality speaks for itself, just have a look and learn how to encode using Mpeg4 aka DivX.


PS: I was impressed with RealVideo 9 and must say its the codec of choice for cartoons IMHO.

[betamac]

I was having the same problem making a good quality DIVX as i want to rip my 30 DVD collection but i found this guide below

http://nickyguides.digital-digest.com/DVD2AVI.htm
using DVD2AVI to start with then going onto

http://nickyguides.digital-digest.com/nandub.htm
Using Nandub and finally for audio

http://nickyguides.digital-digest.com/audio-extract.htm
Using grephedit,

I am ripping to 800 MB file sizes (90MIN CDS) and for 2 hour movies or less the quality is excellent (for more than 2 hours i will use 2 CDs)
The resolution i use is 576x320 for widescreen movies

Hope this helps

[Greg12]

i do not see why would want to put your video into a format you cannot get it out of.

[dausone]

Good stuff...
well I have tried using filters before to minimize noise and have messed with floating point, motion search, soften block noise in TMPGEnc with some fairly good results but I just can't get it to playback on my vcd without the audio and video wigging out on me. I am having doubts about my dvd player, Mintek 2580 becuase of this and the fact that I cant play back SVCD's, or VBR VCD's, (X)VCD's.

NeVeRLiFt, thanks for the info on DivX, but I am not 100% sure that I am willing to give in to this format just yet although it does have its good points when compared to the problems I have been running into. It will always be a possibility to consider if I decide to go with a good video out card in the future.

Adam sorry if I wasnt clear, the input resolution for my DVDRips was 720X480, input resolution for DivX was 640X480. Output resolution for both after encoding was 352X240. I have tried CVD but cant get my dvd player to accept that format.

betamac, thanks I will try your advice on that.

Just a side note, I know there are a lot of posts on this but I am still amazed at the quality of the screener for LOTR. Compared to any DVDRip I have made in the last two months, it is way better in quality, and this is coming from a DivX file. It seems like instead of tring a (x)vcd with 2 pass VBR in TMPGEnc (which my dvd player cant handle), I will experiment with DivX compression to do this (since some have said that DivX compression is more efficient than Mpeg1, Mpeg2) and then use the final DivX to endcode to VCD in CBR? We'll see... the struggle continues.

[NeVeRLiFt]

You will get the best quality if your source is not loss-less meaning this....
If you convert a DivX to VCD it will never look as good as say a Huffyuv or Mjpeg thats been converted to VCD. And if its a DVD then please just rip it and encode it to VCD. Everytime you Convert or encode to something else you lose quality.
As for Mpeg4's future we should be seeing DVD units that support it within the year. And Microsoft already has Pioneer making DVD units that supports WMV9 aka Corona.
And there is nothing wrong with making VCD or SVCD's, just use TMPGEnc or CCE and the quality will be great, just not 1cd
I love using TV-out to watch my movies, works better than any DVD unit IMHO.

I will experiment with DivX compression to do this (since some have said that DivX compression is more efficient than Mpeg1, Mpeg2) and then use the final DivX to endcode to VCD in CBR? We'll see... the struggle continues.

[NeVeRLiFt]

Seems like you dont know what your talking about....
Mpeg4/AVI is really easy and simple to convert.
It can be edited and converted very easy.
So stop talking shit.
RealVideo and WMV are the hardest and worst when it comes to editing and converting.

i do not see why would want to put your video into a format you cannot get it out of.

[vitualis]

It should perhaps be noted that S/VCD playback exists and works consistently on almost all DVD players. Beyond the video, it is also important to note that the format also allows for a standardised system of menuing. For a video disc at present, there is nothing that compares better than S/VCD except for DVD.

Yes, MPEG-4 video can provide excellent quality for size but the issue isn't really that is it? It doesn't really matter how good the quality of the video as it isn't going to look as good as DVD if you are going to use MPEG-4 in conjunction with CD media. Furthermore, there is still the issue of a standardised form of user interactivity. I don't know about you, but popping a VCD or SVCD (or indeed a DVD) into a stand-alone player that is played through a good set of speakers and relaxing with a remote control is somewhat more enjoyable than using the video out of a PC with a keyboard (and yes, I know you can get a remote control system working but for the cost, you might as well have bought another DVD player).

And of course, the clincher still is that no stand-alone MPEG-4 player exists. You talked about not living in the past. Well, I believe in living in the present. There is no indication as yet on whether a stand-alone player capable of playing back ISO MPEG-4 will ever be released. With licensing as it is, there may be all sorts of "copyright" impediments put in place -- or even some sort of MPEG-4 based proprietary format altogether. IMHO, you should never make something that you anticipate will be supported in the future. You should only make something that is supported NOW. Thus, for DivX video, it is still PC playback only.

Regards.

[NeVeRLiFt]

You are right vitualis.
Here it is that Microsoft already has Pioneer making a DVD unit that supports their WMV9 aka Corona and where yet to see a DVD unit coming out that supports Mpeg4.
There is that Archo's jukebox thing though but thats another story.


Cant forget to mention DVD burners, there getting cheaper and people can burn alot VCD's to one DVD