divx 5.03 quality

[killingspree]

somehow i'm getting pretty bad results since i've installed divx 5.03.
even at higher bitrates (close to or above 1000kbit) i'm getting blocks and a lot of artifacts around faces bodies etc. also a lot of movement in walls is visible.
i've attached a screenshot of road trip
encoded @ 950 kbit with divx 5.03 pro in 5 passes (no visible improvement between pass 2 and 5 by the way)
used Quarter pixels and GMC (no bframes, no profile selected)
encoding method:
dvd2avi project
avisynth 2.5 script with no (filters) just crop and resize (fastbilinearresize) and mpeg2dec3
afaik no color conversations in the script (always YV12)
then encoded with Vdubmod.
i haven't done a direct comparison encode (don't ahve the time) but when i looked at movies with similar length done in 5.02 with gknot .27 i found that they looked a lot better although i think they had definitely more movement in them (from dusk till dawn was one of them!)

regards
steVe

[jonny]

even at higher bitrates (close to or above 1000kbit)

There is no high or low bitrate, all is movie dependant.
Compressibility test is a good indicator to see if the bitrate is high or low.

i haven't done a direct comparison encode (don't ahve the time) but when i looked at movies with similar length done in 5.02 with gknot .27 i found that they looked a lot better although i think they had definitely more movement in them (from dusk till dawn was one of them!)

You should do a direct comparison with the same movie (without encoding credits separately) to present a good test.
The fact that 2 movies have similar length is not sufficient (the first movie could compress 2 times compared to the second movie).

Only some suggestions, it whould be a really interesting thing if you find the time to make this kind of test (instead of making 5 passes in one movie).

Cheers
jonny

[Evil Andy]

I think it's widely accepted that Road Trip doesn't compress well.

You might try turning off QPel. It was bust a couple of releases ago and I'm not sure it's fixed yet.

[killingspree]

ok i'll see if i can do some testing, i got a week off school right now, so it should work out... just hate installing around with two versions of divx...

anyhow, i've done another movie earlier (actually just the night before i did road trip, and it came out pretty crappy two, way below my expectations...

any reasons why roadtrip doesn't compress so well? i mean it doesn't look too hard to encode at first sight?!?

regards
steVe

[jonny]

Never done this movie, anyway, why don't you make a comp. test?

[killingspree]

ok... i've done the comp test you described in the your thread (manual)

http://forum.doom9.org/showthread.php?s=&threadid=44414

the value i've gotten is 34.02
the question i've got now is: is this the eact same value you get when using gknot?? then compressability wouldn't be too bad ?!

please correct me if i'm wrong

regards
steVe

[Evil Andy]

Ewwwwww!!! That's roughly equivalent to Gordian Knot giving 35% and you should be aiming for at least 60%

What resolution are you encoding at?

[jonny]

!!!

If you are not using b-frames is really near to the real value!
(if you are using b-frames, please, use divx5enc for the test)

Anyway, b-frames or not, the value is for sure TOO LOW :eek:
(why people keep not using the compress test? it's so useful :D)


EDIT: i see you have not used b-frames, so the comp.test value is correct...

[Acaila]

any reasons why roadtrip doesn't compress so well? i mean it doesn't look too hard to encode at first sight?!?I can think of two obvious reasons.
1) It's 4:3 AR. More pixels means more space needed.
2) It's a nice, bright, shiny movie. Most movies of the same type as Road Trip are bright with vivid colors. And that's hard to compress.

[jonny]

Yes i 100% agree.


I can think of two obvious reasons.
1) It's 4:3 AR. More pixels means more space needed.
2) It's a nice, bright, shiny movie. Most movies of the same type as Road Trip are bright with vivid colors. And that's hard to compress.


Another example of bad compressibility is "Knight Tales" (and is a 2.35 movie!)

[killingspree]

Originally posted by Evil Andy


What resolution are you encoding at?

resolution: 576,320

so i think i could go qutie a bit down there... any recommendations?!?

1) It's 4:3 AR. More pixels means more space needed.
well i don't know what the AR means... but afaik it's normal 16:9

anyway... since i'm not going to use 2 CDs... how else could i improve compressability?

regards
and thanks very much for your help!
steVe

[jonny]

B-Frames for sure.
Also you could consider to go for 2CD+B-Frames, so you'll be probably able to raise the resolution.

[Evil Andy]

Well your screenshot looks 16:9 to me.

I agree with jonny I think you'll have to bite the bullet, put on B-Frames and go for 2 CDs.

[killingspree]

i've heard that b-frames can f*** up your movie too... anything true about that... what about Qpel and GMC, do you recommend using it??

thanks again...
steVe

[killingspree]

ok fu** it anyway.. i'm going for two CDs with ac3... probably add another sound too...

anyway thanks for your help...
regards
steVe

[jonny]

No problems for me with B-Frames and the 5.0.3, i know others have problems... but the best way is that YOU test this.
I don't like to use GMC & QPel, mainly because my pc is slow... so i can't answer to this ^^'

[Evil Andy]

I've heard mixed reports about b-frames in 5.0.3, some people have no problems others get artifacts. I personally haven't had any problems and they DO improve compressibility significantly. GMC and QPel supposedly give slight quality improvements but not enough to justify the longer encoding time.

[killingspree]

it's probably best to use b-frames and GMC and Qpel don't do any harm but over their use can be argued...

steVe

[N_F]

I actually ran some tests on B-frames, GMC and QP earlier today (with DivX 5.03).

My results confirmed what people usually say: Only use B-frames, forget about the other two "pro features". GMC didn't really make any difference that I could see, but QP made the frames more blocky (just like one can observe in your attached screenshot).


I have Roadtrip on 1 CD encoded with DivX 3 SBC (not by me...), and from what I can remember it was nothing special about it, not bad quality, not the best ever (don't take this as DivX 3 SBC would give better results, I'm confident DivX 5 is just as good (or better)).

[Assault]

@ killingspree
You could try different smoothers like deen or fluxsmooth to improve compressibility. Then you could perhaps go for one cd.

Regards
Assault

[codename_46]

Actually the picture you've posted looks almost just like the copy that I have of Road Trip which I think came out pretty good actually. I used DivX 5.2 (regular not pro), no B-frames, and fit it all on a single CD.
If you want to try encoding a movie that comes out beautiful on single CD try Pitch Black ;)

[codename_46]

I'm having another interesting problem with DivX 5.03. I've encoded a copy of We Were Soldiers. In the slow scenes the video comes out looking ok, but during action scenes it turns very blocky and pixelated. Also the .avi isn't comming out the right size. I set it for 700MB and instead am getting about 900MB.
Anyone else having similar problems?

[killingspree]

Originally posted by codename_46
I'm having another interesting problem with DivX 5.03. I've encoded a copy of We Were Soldiers. In the slow scenes the video comes out looking ok, but during action scenes it turns very blocky and pixelated.
this sounds like you chose a low bitrate... iirc we were soldiers is a pretty long movie - 2 hours+; and since it is a war movie with lots of explosions, fast fight szenes, etc it will need quite a lot of bitrate anyway, so my recommendation would be to go for 2 CDs... IMHO you cannot fit every movie on one CD. and i think the movie is worth the 2 CDs !!
of course this is your personal choice and no one forces you to use more than one CD, if you don't want to.... (:

Also the .avi isn't comming out the right size. I set it for 700MB and instead am getting about 900MB.
Anyone else having similar problems?
ok this sounds like a faulty settings, but i can't judge anything, since you didn't state your encoding method, avs file, etc...

[crahak]

Well, GMC wise, the only movies I've encoded with it have grey "blotches" that stick around for a couple seconds, and problem went away when I disabled the setting... B-Frames only work very well for me :)

As for 5.0.3 and pixelization and such, I had that too. About the filesize problem (I've been encoding for a little over 2 years, mainly with Gordian Knot, or directly from Virtualdub), using 5.0.2 Pro, I get the proper filesize give or take a meg... With 5.0.3, my encodes that (with the same bitrates and all) turn out to a nice 700 meg turn out to be sometimes a Gig... It didn't seem to improve quality (rather the inverse), multi pass don't seem to make such a great deal of a difference (especially at very high bitrates), filesize problems, so I gave up on it. I'd probably convert to xvid before I try 5.0.3 again.