If you want QUALITY don't use b-frames or gmc

[werky]

Why?

I started my tests only with version of DivX 5.02, before i was using DivX 4.12.

Title: Planet of the Apes (2001)
Machine: AMD 1400; S0: Win2000
Method: avisynth + VirtualDub
ReSize: 640*270; neutralbicubic
Encoding: 1-pass Quality Based at 100% (Best quality possible)

Divx 4.12 version
Filesize: 1.18 Gb
Quality: Very Good Quality, the best the codec can achieve.
Almost 0% macroblocks, the image is sharp even in the high action scenes.

DivX 5.02 with b-frames & gmc ON
Filesize: 918 Mb
Quality: Good Quality, not the best we can get with DivX
To much macroblocks in comparison with version without b-frames. And the blurring is to much obvious in the high action scenes.

DivX 5.02 with b-frames & gmc OFF
Filesize: 1.18 Gb
Quality: Completely equal to our 4.12 version

So what can we think about this test?

- Divx 5 is not so diferent from divx 4.
- If you want Little file size, use b-frames.
- If you want Quality don't use b-frames.
- b-frames are good to make movies to put on the net.
- if you want to make a good divx movie to your collection don't use b-frames.


PS: if anyone here wants to see some screenshots, of what i'm talking about. let me know so i can post them in the web.


by the way thankx the wef for your good program (gknot) and a special thankx to doom9, your site is our bible.:cool:

sorry 'bout my english. i'm portuguese :)

[Acaila]

Of course B-frames look bad, they are intentionally encoded at twice the quantizer of a P-frame because they contain less errors. So naturally you'll see more blocks on a still B-frame. It's just that when watching a video containing B-frames you will no longer notice these blocks.

[werky]

What i was talking was not about still frames.
i was talking about moving pictures.

with b-frames in a scene with action, fire and water you can see your b-frames in action blurring everything around.

i never talked about still frames. i talked about screenshots only, because is the easy way to show the problem in the web. but i can post 20 seconds of the movie, just to show you the blurring.

this theory about b-frames not noticeable in moving pictures, is just theory. and can fool the eye if you stay at a good distance from the monitor. but when you look at the picture and analyse it you will see the problems, the artifacts, the blurring, the less detail.

don't forget we're talking about a good backup of a movie. a backup o coulf last some time, and with waht you could in the future make a conversion to a mpeg-2 file, for example, if you want it.

[theReal]

I'd say for a really good backup, just copy the .vob files - it's very fast, you get perfect quality and this on only a couple of cds more than divx ;)

[ChAoS Overlord]

What if you use
a) ONLY B-frames
b) ONLY GMC

Do the test... (btw: you're the first to note this problem...)
I always use only B-Frames

[DJ Bobo]

I agree with theReal, DivX isn't suited for archiving, DivX is far from perfect image quality, even with quality based 100% (with or without b-frames or whatever you want).

So if you want archival quality, keep the DVD!

[Snollygoster]

Guys, this test is useless. Noone uses 1-pass 100% Quality.
We could have kept the vobs...

The thing is that in lower bitrates B-Frames an GMC do the job quite handy. Compare 4.12 to 5.0.2 and tell me. Not for 2GB files but for 600MB or 1GB max...

[werky]

Answering to Chaos.

I tried the test with the 2 settings separate.

You can see what i'm talking in this 4 files. these are video files not stills. but don't worry i cut it to little pieces of 1 mb each.

1) Divx 5.02 without any feature (not b-frames and not gmc)
http://clientes.netvisao.pt/werky/Planet_Divx5_OFF_00.avi
2) Divx 5.02 with only GMC activate
http://clientes.netvisao.pt/werky/Planet_Divx5_gmc_00.avi
3) DIvx 5.02 with Only b-frames activate
http://clientes.netvisao.pt/werky/Planet_Divx5_bframes_00.avi
4) DIvx 5.02 with b-frames and gmc activate
http://clientes.netvisao.pt/werky/Planet_Divx5_bframes+gmc_00.avi

my conclusions

1- GMC doesn't do anything noticeable. with or without it you can't see anything that really matters.
1- b-frames really reduces the file, but shows more macroblocks.

See the begining of the file the scene is full of macroblocks with b-frames but this happenning much less with b-frames off.


Answering to Snollygoster, bobotns and theReal

I don't see what do you're really talking about. What do we all want? Best quality at a reasonable filesize.

So i've done the test with quality 100%, just because this gonna take me only 2 cds. And 2 cds for movie of 120 minutes i don't think i'm really exagerating.
Like i've show to you the file take 1.18 Gb with b-frames off and 918 mb with b-frames active.

If you want to compare a file (vobs) with 6 Gb with one with 1 Gb (divx) well, it's your problem.

To bobotns, do you really think mpeg4 (divx) is so far from archival quality?????
So why the Big Studios are thinking about Mpeg4 for the next step to High Definition DVDs instead of BlueRay with Mpeg2 ???

To Snollygoster

Like i've said above. Divx 4.12 and Divx 5.02 with b-frames off, is pretty much the same thing.

- i'm just searching for the best quality possible with reasonable filesize, with the tools we all got.
- i'm just looking for some feddback on quality on divx 5.02 about the b-frames

[DJ Bobo]

@ werky
Very simple: you can use what ever settings you want with DivX or MPEG4 in general, you won't be even close to the quality reached by MPEG2 with high bitrate. MPEG2 is almost too good compared to DivX using high bitrates.
DivX is like you said suited to put a movie anyway on 1 or 2 CDs. Quality freaks will keep the DVD, since the very best DivX will never attain the quality of the DVD, it's as simple as that.
And the big studios aren't planning using MPEG4 or what so ever, big studios have other ways to store their movies.
What the customer becomes is another thing.

[Ripping 3ngine]

1) Divx 5.02 without any feature (not b-frames and not gmc)
...
4) DIvx 5.02 with b-frames and gmc activate

@werky:
hu? look at the file size of the two samples!

[werky]

@bobotns

read this article, and search in the net all articles about the future of dvd, blu-ray, mpeg2 and mpeg4.

http://www.cdrinfo.com/Sections/News/Details.asp?RelatedID=2098


@Ripping 3ngine

What do you mean?

1) Divx 5.02 without any feature (not b-frames and not gmc)
- 1.11 kb for 3 seconds of action
if you multiply by 1000 = 1100 Mb

4) DIvx 5.02 with b-frames and gmc activate
- 860 kb for 3 seconds of action
if you multiply by 1000 = 860 Mb

this is aproximately the filesize of the total encoded movie.

[Shuichiro]

You mean 860byte do you? ;)

[jonny]

@werky:

If you want to make a good test, use the same bitrate and encode with & without bframes (2-pass), than tell me what is the best for you.

[DJ Bobo]

@ werky
That's why I said "What the customer becomes is another thing"
"Adopting MPEG4" is not equal to "MPEG4 is suited for archival quality", the same big studios you're talking about released the VideoCD standard which is even worse than MPEG4, I think that says it all!

So setting B-Frames off because they avoid archival quality is bullshit, since one can't talk about archival quality at all using DivX!

Saying that B-Frames makes quality worse is RELATIV, it depends on the setting you're using. If you use quality based 100% and you still can put the movie on 2 CDs, I won't bother myself with B-Frames or what so ever. In any other case, especially in 1CD rips, B-Frames & GMC are vital and will give you BETTER quality.

That's why there is a theory in this world, called "theory of the relativity" ;)

[JimmyBarnes]

Originally posted by bobotns
I agree with theReal, DivX isn't suited for archiving, DivX is far from perfect image quality, even with quality based 100% (with or without b-frames or whatever you want).

So if you want archival quality, keep the DVD!

In a very real sense the DVD is just a shadow or reflection of the original film frame (or directly digitally acquired image) - vastly more than 720x576. I've seen some DVDs full of compression artifacts (Jumanji a notable example). DivX in turn is just a shadow or reflection of the DVD.

As you say, it's all relative

JB

[DJ Bobo]

@ JimmyBarnes
You're right, every time I see a bad mastered DVD, I tell myself "man, if I was the author, I would have done it better" :D
But hey, DVD is the best a home user can get ;)

[JimmyBarnes]

Originally posted by bobotns
@ JimmyBarnes
You're right, every time I see a bad mastered DVD, I tell myself "man, if I was the author, I would have done it better" :D

But hey, DVD is the best a home user can get ;)

At the moment.

Can't wait til these blue laser 27 GB DVDs are the norm for home use -then standard DVD res will be something like 1440x1152 (betcha some klutz will still make crappy masters) and we'll all have 60" flat panel plasma displays ($299 from WalMart)

Course by then the studios will be into full colour, life size 3-D holographics ;)

I'll stop buggin' ya now :devil:

JB

[werky]

I know that DivX(Mpeg4) can't be a good way to make archival quality.
Neither mpeg2 and even less mpeg1.

But i was wondering, where can i find a good suport for archival quality???

Do you realize that this guaranteed suport doesn't exist!!

Even the film, the master who can serve as source to every other kind of support isn't as good to archival purposes.

It's necessary to spend a very large amount of money to store the film in good conditions and even with that conditions the film will be damaged anyway, after years.
And after that years, you'll got to spend even more money to restore the film.
And at last we need to thank's, digital technology, who gives us tools to make that restore in some good conditions.

This isn't just relative. This is our Time and our Life.
And we just need to choose the better path to follow.


enjoy good movies

[JimmyBarnes]

Originally posted by werky
Even the film, the master who can serve as source to every other kind of support isn't as good to archival purposes.

It's necessary to spend a very large amount of money to store the film in good conditions and even with that conditions the film will be damaged anyway, after years.

And after that years, you'll got to spend even more money to restore the film.

enjoy good movies

George Lucas has shot much of the new StarWars in Australia. According to someone who had a small acting part in one of the the films, he's using direct digital acquisition for "filming".

Filmmakers are used to saying, If it's on film it's important, If it's on video, it's not important. But this new digital "video" is now equal in visual quality to film.

I hope this gives you hope :)

JB

[DJ Bobo]

Oh yeah, I read about it somewhere, he's using some brand new hi-res digital cameras from Sony or Panavision.
Well, I think we already have the technologies to store a film perfectly. They should put their films on High Quality digital Bands or Discs with lossless compression and high error protection.
I think that could last for at least 100 years without any quality degradation.

Talking about those BlueRay Discs, at that time, we won't be talking about CDs anymore, we will be talking about 1-DVD Rips, and other wanting 2-DVD Rips with double DTS-ES sound and stuff at any price, that will be exciting!

Like the man said: History repeats itself!

[theReal]

Can't wait til these blue laser 27 GB DVDs are the norm for home useSomeone posted a link to an article recently that said that blue laser will not be the next upcoming standard, because the industry leaders agreed that it was too expensive. The article also said they already agreed on using high-bitrate mpeg 4 compression on standard dvd media for hdtv content.
So much about "master quality" ...

Sorry, I don't have the link to the article anymore.

[JimmyBarnes]

Originally posted by theReal
Someone posted a link to an article recently that said that blue laser will not be the next upcoming standard, because the industry leaders agreed that it was too expensive. The article also said they already agreed on using high-bitrate mpeg 4 compression on standard dvd media for hdtv content.
So much about "master quality" ...

Sorry, I don't have the link to the article anymore.

See
http://www.cdrinfo.com/Sections/News/Details.asp?RelatedID=2098

Leading paragraph states:

DVD Forum chooses RED than BLUE laser for the next DVD format
Friday, 1 March 2002

The look of the next generation of digital video disks got harder to call when the DVD Forum's Steering Committee voted this week to approve the use of low-bit-rate compression for high-definition DVD. The DVD Forum's decision, made at a meeting Tuesday (Feb. 26) in Tokyo, to stick with a red-laser-based scheme but switch to low-bit-rate compression, came only a week after nine of the world's biggest electronics companies agreed to promote a blue-laser-based format for next-generation video and computer optical disks.


JB