Quantcast DVD2one's Method for Quality/Size Prediction is Buggy! - digitalFAQ.com Forums [Archives]
  #1  
02-19-2003, 08:08 PM
kwag kwag is offline
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Just want everyone to be aware of something I've found.
Today I decided to try setting the "Used defined" size on DVD2ONE to 800MB. My idea was just to test what kind of quality it would produce on a 800MB size disk. To my surprise, when DVD2ONE ended the process, this is what I got:

Code:
VTS_01_1.VOB 1,048,547 KB
VTS_01_2.VOB 124,520 KB
VIDEO_TS.BUP 6 KB
VIDEO_TS.IFO 6 KB
VTS_01_0.BUP 68 KB
VTS_01_0.IFO 68 KB
Obviously, something is wrong . So I decided to play the VTS_01_1.VOB in WinDVD, and to my surprise it started looking EXTREMELY GOOD
Look at a screenshot near the beginning of the VOB:



Now look at one near the middle of the VOB :



And look at one near the end of the VOB :



As you can see, DVD2ONE is reducing the bit rate linearly towards the end of the movie, and the quality degrades. Guess I found "the truth" about something internal to DVD2ONE which i don't like

-kwag
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  #2  
02-19-2003, 10:42 PM
black prince black prince is offline
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@Kwag,

Let's take a 2hour movie, use KVCD 704x480, a CQ = 15 in
Tmpgenc and make it fit into 1 CD (800MB) and expect it to have DVD
picture quality. I'm not sure what your trying to prove. I believe a
program with the size of 103KB, transcoding DVD files is not expected
to anticipate situations like that. Even CCE or IC couldn't win a test
like that. KDVD in certain situations will out perform DVD2one, CCE,
and IC. But to make a fair test, make IC perform the same compression
(movie only) and target size of 800MB. Let's see what it's algo
does with that target size. It could be even uglier.


-black prince
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  #3  
02-19-2003, 11:00 PM
kwag kwag is offline
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Quote:
Originally Posted by black prince
@Kwag,

Let's take a 2hour movie, use KVCD 704x480, a CQ = 15 in
Tmpgenc and make it fit into 1 CD (800MB) and expect it to have DVD
picture quality. I'm not sure what your trying to prove. I believe a
program with the size of 103KB, transcoding DVD files is not expected
to anticipate situations like that. Even CCE or IC couldn't win a test
like that. KDVD in certain situations will out perform DVD2one, CCE,
and IC. But to make a fair test, make IC perform the same compression
(movie only) and target size of 800MB. Let's see what it's algo
does with that target size. It could be even uglier.


-black prince
Hi black prince,

I'm just pointing out that DVD2ONE has a "Decaying" quality the longer the movie is. I verified this against my original VOBs, where the average bit rate is very close on all VOBs, but on the new VOBs that DVD2ONE created, on the last VOB the average bit rate is lower than on the first VOBs . That clearly tells me that the size prediction on DVD2ONE is faulty The point is that the quality is not constant throughout a movie done with DVD2ONE, but it is constant with IC ( I just verified that ). The quality on the movie "The Bourne Identity" done with IC simply blew away DVD2ONE! Now I have to agree with the German article and the screen shots they posted. I think it's worth the 2+ hour wait for IC to encode
As for a 2 hour movie done with KVCD 704x480 PLUS on one CD (MPEG-1 of course ), yes it blows away both IC and DVD2ONE, even though it will still have blocks but far less than those two programs
A KDVD MPEG-2 encoded of ~1.5GB gives the same quality of DVD2ONE with a size of ~2GB. That's a huge difference . I'm not saying DVD2ONE is bad. I'm saying it has some flaws that I can't tolerate, and that is un-constant quality throughout a movie. Maybe not noticeable on ~1:45 movies or so, but on 2+ hour movies, it definitively shows

-kwag
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  #4  
02-19-2003, 11:02 PM
rendalunit rendalunit is offline
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kwag, I believe you've shown that the algorithm in this prog kinda sucks because a better algo would create a uniform quality or avg bitrate level throughout the whole thing. I wonder what it looks like in bitrate viewer-- maybe like this:
Code:
  
\
  \
    \
      \
        \
          \
            \  
              \
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  #5  
02-19-2003, 11:11 PM
kwag kwag is offline
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Quote:
Originally Posted by rendalunit
kwag, I believe you've shown that the algorithm in this prog kinda sucks because a better algo would create a uniform quality or avg bitrate level throughout the whole thing. I wonder what it looks like in bitrate viewer-- maybe like this:
Code:
  
\
  \
    \
      \
        \
          \
            \  
              \
Yes, but not that sharp
Actually what you see in bitrate viewer is that at the beginning of the display, the bit rate follows the Q very closely, and further towards the end, you see more distance between the bit rate and the Q. That of course means lower quality.

-kwag
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  #6  
02-19-2003, 11:18 PM
black prince black prince is offline
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@Kwag,

If what you found is true, maybe we should invite DVD2one into this
discussion and have them verify your findings (if their willing). They
are registered with Doom9 and respond to their questions. I'll
PM them with you findings and invite them to resopnd here or
at their own forum (if you don't mind)

-black prince
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  #7  
02-19-2003, 11:24 PM
kwag kwag is offline
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Quote:
Originally Posted by black prince
I'll
PM them with you findings and invite them to resopnd here or
at their own forum (if you don't mind)
Of course Maybe they can explain or acknowledge some bugs
Go ahead . But I'm positive they didn't even test their "User defined" setting before releasing the software. That is, to consider every end used changes ( even if they're absurd ). That's real SOP ( standard operating procedures ) for software testing

-kwag
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  #8  
02-19-2003, 11:38 PM
black prince black prince is offline
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@Kwag,

I PM'ed ReneB, the developer working with Erwin and invited him to
respond to your findings. Let's wait and see what he says. If this is
true that bitrate decreases, albeit slowly, towards the end of a movie,
that is something which I DON'T LIKE EITHER

-black prince
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  #9  
02-20-2003, 07:45 AM
black prince black prince is offline
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@Kwag,

I posted this link on DVD2one and here are some responses about
your findings of quality/size prediction:

http://club.cdfreaks.com/showthread....threadid=64673

They seem to feel, so far, you are abusing the software and your
tests are not normal use situations. DVD2one is anticipating DVD
movie sizes (5GB to 8GB) compressions and not 5GB compressed to
800MB. I'd still like to know why bitrate can't be consistant to the
end of the movie.

-black prince
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  #10  
02-20-2003, 08:27 AM
black prince black prince is offline
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@All,

ReneB (DVD2one) wrote:
Quote:
ReneB
Moderator



Registered: Jan 2003
Posts: 162
Re: DVD2one has problem with quality/size prediction

quote:
--------------------------------------------------------------------------------

black prince wrote on 20-02-2003 05:34:
@Hi ReneB,

I would like to invite you to KVCD.net and respond to questions
about DVD2one's quality/file size prediction. It seems there are
some problems and we hope you would be kind enough to
answer the questions at our forum:

http://www.kvcd.net/forum/viewtopic.php?p=17377#17377

I have DVD2one v1.01 and believe it's a great product. Others
at our forum are questioning it's ability distribute bitrate over
movies 2+ hours and found it decreases bitrate the closer it
get to the end of a movie. Please respond when you can

-black prince

--------------------------------------------------------------------------------



Thank you for your support,really apriciate that

Let me tell you the original goal of DVD2one that Erwin and I had in mind while developing DVD2one.

The idea was that we wanted a tool to shrink movies that where a bit to large to fit on a blank DVD-r.
Say a 5.3 Gb movie, so we needed to decrease it a bit and that within 15 minutes on my system (athlon xp2100).

Todo this we build the current engine, which does a aprox estimiate of the ending size and constantly measuring the end-size.

In the real world people (including me) started to use this tool to shrink movies from 7.1 Gb to 4.3 Gb.
Unfortunally our engine wasn't really build for that, it works but not as good as Tmpeg or CCE would.
But that's because we only compress the movie instead of rebuilding it frame by frame. Like you would with a encoder,

That's why we are improving the engine as we speak. Erwin and I had a good discussion about the Quality factor last night, and we came up with an idea to improve that.
(by making some sort of multipass engine)

The making of this engine is going to cost us some time for sure.
Because like you know we build everything ourselves from scratch
But the quality factor for larger movies is going to be improved in newer versions, i can personally asure you that!.
But please be a little bit patient with us, we are only a one and half man show
__________________
--
Rene
Here's the response from DVD2one.

-black prince
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  #11  
02-20-2003, 09:32 AM
urban tec urban tec is offline
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Well I added my 2cents to that thread, you would think that they would take a more informed view.

I am impressed by ReneB's reponse, sounds like Dvd2one will only get better from here.
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  #12  
02-20-2003, 11:53 AM
kwag kwag is offline
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It's good to hear they have a great positive attitude
Let's hope that their next version does correct the problems. For now, I'll be using IC, as I rather wait ~3 hours and have better quality. I really like DVD2ONE's speed, but I'll use it only on movies ~5GB or so. For larger DVDs, IC is really much better (for now )

-kwag
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  #13  
02-20-2003, 05:28 PM
DVD Master DVD Master is offline
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@Kwag:

Have you tried InstantCopy from Pinnacle Systems? Is better than DVD2one (better transcoder an can make a 1:1 copy of DVD9 ), also is cheaper ($19.00 after rebates at J & R, and they deliver to P.R.)

DVD Master
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  #14  
02-20-2003, 05:45 PM
black prince black prince is offline
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@DVD Master,

IC is InstantCopy which Kwag uses to compare with DVD2one.

-black prince
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  #15  
02-20-2003, 06:44 PM
kwag kwag is offline
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Quote:
Originally Posted by DVD Master
@Kwag:

Have you tried InstantCopy from Pinnacle Systems? Is better than DVD2one (better transcoder an can make a 1:1 copy of DVD9 ), also is cheaper ($19.00 after rebates at J & R, and they deliver to P.R.)

DVD Master
Hi DVD Master,

black prince just answered the question
As you are here in Puerto Rico, you can get all Pinnacle producs at "Computer House" Tel (787)-792-8726.
They carry the complete line of Pinnacle products

-kwag
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  #16  
02-20-2003, 08:50 PM
DVD Master DVD Master is offline
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@kwag:

Well, I think that DVD2one has lost to much time since its first release. Even when it is extremely fast some options are needed. Recently they add an option to decrease the file size, this option doesn't work for small files, like previews, menus, etc. So if we want to do a 1:1 copy we still have to use jdobb's "Makeiteasy".
Automatic 1:1 option is still not implemented. And the most important, when transcoding big files (larger than 6 GB.), transcoded movie has a lot of artifacts (macroblocks; especially in darks scenes, some trembling or shaking of the movie, some softening, lost of contrast, etc.), so some modifications most be done to the transcoder.
Some people are having problems with InstantCopy, but it really do a decent job transcoding big movies to fit in a DVD5, and it also copy menus and extras.
So, even if InstantCopy is slower, I will keep using it intead of DVD2one...

Regard,

DVD Master
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  #17  
02-20-2003, 09:47 PM
kwag kwag is offline
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Yes, I agree with you. DVD2ONE needs a lot of work. It really shines on short (~5-6GB) movies, but not on longer movies. And if you want to blast away DVD2ONE and InstantCopy, go for KDVD
If you haven't seen what it looks like, take a look here and download the first sample in this thread: http://www.kvcd.net/forum/viewtopic....=asc&start=540

-kwag
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  #18  
02-21-2003, 06:41 AM
DVD Master DVD Master is offline
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@kwag:

Any real encoder (TMPGEnc, CCE, PROcoder, etc.) can easily beat DVD2one or IC in quality. But at this moment I don't have enough time to do all this process the "old way" (DVD2AVI, TMPGEnc, Subrip, DVD Maestro,...), so I am looking for a good transcoder...

DVD Master

PD: Have you tried Chatwalker's DVD2DVDr program? http://www.dvd2dvd-r.de/index.php
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  #19  
02-21-2003, 09:46 AM
kwag kwag is offline
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Quote:
Originally Posted by DVD Master

PD: Have you tried Chatwalker's DVD2DVDr program? http://www.dvd2dvd-r.de/index.php
Yes. I believe that's the program that uses CCE as an encoder?
I looked at it about a month ago, but when I found out it used CCE, I didn't try it. We just get equal results with TMPEG and our own optimized Q Matrix. This way, and CQ mode, matches ( or exceeds ) CCE in MPEG-2. At least on bitrates ~5,000Kbps which is what KDVD Full D-1 template is set to work at.

-kwag
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  #20  
02-21-2003, 11:10 PM
black prince black prince is offline
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@All,

I guess I've become spoiled by the speed of DVD2one. I'll be happy if
Erwin and ReneB improve picture quality only by sacrificing a little more
transcoding time with a single pass of the vob's to determine bitrate
distribution and a transcode phase. I can wait 1 hour for a final copy.
As for backups, I don't need an exact copy, with menus, subtitles, etc.
I just want the movie only, with good quality. I suport DVD2one for
putting transcoding programs on the software backup map. I encourage
them to stay the course just as KVCD has successfully done.

-black prince
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