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View Full Version : Strange bug with DivX 5.05


emilyo
7th May 2003, 09:31
I encoded Matrix two times using GordianKnot 2.8 with different settings.I only changed the resolution.
Other settings were same.AC3 sound.(I'm sendig the files without sound for file size reduction)(GMC and Bidirectional Enc. on, QPEL off)as Doom9 suggests.
2cd in both encode proccess.2 pass in both encodes.
File size prediction was nearly perfect and file spliting worked well for me.My problem is with visual problems.
First I encoded with res. of 640x256.Movie was encoded perfectly in general.(much better than 5.02).But when I
watched a part (Look attachments[clip1.avi]) of it I noticed a strange bug.(think a scene with a very low bitrate).
I looked for another strange part but I couldn't see in the whole movie.Only this scene was encoded wrong.But EKG seemed Ok to me.
In my second encode(704x288), this part was OK.But I noticed another strange thing.I think there was a keyframe insertion error in this scene.
When you watch it in full speed you can see a short flicker.But when you look at that frame in virtualdubmod you can see a keyframe with full
of macroblocks.There may be other bugs too in my encodes.But these are enough for me to not to encode any movie unless DivX 5.06 distribution.
Also my first encode had a seperate end credits(Q=20).Second didn't.
I think these bugs are 5.05's fault.
I noticed a bug in DivX5.05 gui.(-bvnn 290 -psy 1 -key 300 -log "D:\DVD\matr\matr_1.log" -w -mv "D:\DVD\matr\matr_1.mv" -b -g -pq 5 -vbv *2900000*,3145728,2359296 -profile 0 )
the part between stars "*" does not change when you slide the "Encoding Bitrate" slider.If you change and then click other pages in the gui for a while,
it appears to be OK after that.
I can answer any questions about this post.
http://www.students.itu.edu.tr/~kondur/clip1.avi
http://www.students.itu.edu.tr/~kondur/clip2.avi

-----------------
BARIS KONDUR
-----------------
From TURKEY

EagleDM
16th May 2003, 17:01
Did you encode the movie with multipass method or the old 2-pass?


the new multipass gave me headaches with this movie, I switched back to the old 2-pass and the movie quality is now top-notch.

(I encoded with No GMC, no Psychovisual, B-frames enabled) at 704x288 with AC3)

Ewi
16th May 2003, 18:08
If I check your file with DivX DRF Analyzer it tells me the following:

AverageKeyDRF: 21.00
MAXDRF: 31
AverageDRF: 20.42
Deviation: 13.50

DRF means quantizer. This IS a bug!! It is practically not possible in an overall good rip that somewhere a 31-quant is used. It is interesting that your AverageKeyDRF is exactly 21.00. Since there are 3 keyframes in clip1, it would be possible that it used 2 times quant 31 and one time quant 1. DivX DRF Analyzer is not able to show the quant of a given frame...

emilyo
19th May 2003, 16:09
I encoded the movie with multipass method not the old 2-pass method.
Quality is excellent excempt these clips.I don't understand why it happens.What is the difference between old 2-pass and multipass method.are they same when i use multipass method with 2 passes.

Ewi
19th May 2003, 20:03
They introduced a whole new bitrate control algorithm in 5.03. This was broken in 5.03 cause of a memory leak. That was fixed by 5.04, but it had an issue with inserting only I frames (with non Vdub encoders). 5.05 fixed this; at the moment they are looking for this issue that you are experiencing. In their forums you can read that this 5.05 issue is not directly related to the 5.03 blocky-picture-memory-leak error and that it appears less often; don't know if that's true...