Poor quality problem in some DVD below 4000 kbits

[DaRtHmAuL]

hi guys,
i'm just wondering about the quality of the ouput stream.
I've just finished to encode T3: RotM (PAL) with the BIG3 at 3900 kbits, bias set to 30, IQP to 26 (using CCE 2.67.00.27)... the whole process in 4 passes.
I'm using DIF4U 1.4.7 + BatchCCEWS 0.9.1.5 + CCE 2.67 (ECL 1.81/AviSynth 2.5.4)
The result is poor (i presume)... artefacts and very blocky in high motion scenes and some artefacts in slow motion scenes.
Something wrong ?
thks for help
cya

[Chubmeister]

I don't have this disk to hand, but I have done the very same including the DTS soundtrack and I bet I couldnt encode above 2500, 3 passes and it looks superb on a 32" wisescreen! Will check bps when I get home.

I have noticed on a couple of occasions that the assests imported into BATCHCCEWS are showing tiny kbps, like 1400 or less when it should be much more, it's as if I havent had the check for duplicate vob ids set in DOITF4U. Whenever this happened I started over and run DOITF4U again, without changing anything and it worked as expected, maybe you've run into one of these strange blips. Have you checked the kbps rates in a software player or are you reporting what DOITF4U selected and what you assume BATCHCCEWSs actually used?

Chubs

[DaRtHmAuL]

Hi Chubmeister,
there is no prob with the assets. I checked the bitrate using PowerDVD and it looks good. the bitrate oscillates between roughly 2.75 and 4.5mbps (maybe 5.0). The results remains unpleasant anyway.
The video is slobbery, blocky. It's the same for many recents backups i've done like HP and the philosopher's stone, etc...

thks for help
bye

[influenza]

What encoding method are you using? Multipass or roba? cause there have been an issue with roba not doing multiple passes, but starting a single pass over and over again (need to change some things in the eclcce ini).

Well we all know that bitrate isn't a really good predictor for quality, but i would say it's safe to assume that a progressive source would look really well using a 3900 bitrate.

[DaRtHmAuL]

Hi influenza,
my project is pal interlaced (detected by DIF4U) but i've choosen to not deinterlace with decomb.
I'm using multipass template in BCCEWS with standard matrice.
I set the VafFix=1 parameter in eclcce ini file.
can i send you some screenshots ?
thks
bye

[influenza]

But is the source truly interlaced? Most pal sourced are flagged interlaced, but are progressive. If the source is interlaced it needs a lot more bitrate and in that case 3900 could be not enough.

[DaRtHmAuL]

Well the stream is flagged interlaced of course but there is no black lines visible... so it should be progressive isn't it ?
And in this case, have i to check the progressive box instead of leaving it unticked ?
cya

[Chubmeister]

Just checked my back-up and it also looks to be around the 3900 kbps average checking on powerdvd, i have kept the dvd same as original including DTS track, lowest scene I see is about 2250 upwards to 7000+ in the high action sequences and not a pixel out of place, it is truely superb.

Sorry, not much help, except that it looks like something has gone wrong for you.

[DaRtHmAuL]

Yes, it seems something goes wrong.
I tried to reencode in progressive but without success.
I don't see what i have to do to get better quality. Could it be a codec/software issue ? Wrong decoder installed ?
The quality is comparable to a dvdshrink output stream... mosquito noise, blocky artifacts, etc...
I need some advice plz.
thks you
cya

[Trahald]

2 questions.. what is your max bitrate.. and how does it compare to the original. ive done some encodes that have ringing and blocking.. . then i look at the original and its just as bad(and yes im talking about commercial dvds). At 3900 your really should be getting great quality.. even with the demands of pal/interlace. you can try lowering bias to 20 to give the encoder more room to breath around fast scenes. also qp of 16 may improve things as well (16 is default )

on other thing.. when you use progressive. make sure zigzag scanning is on. you may have already.. just making sure

[DaRtHmAuL]

Hi,
bitrate variation seems to be ok.
The video stream i'm talking about is encoded with the following settings : Bias=30, IQP (CCE 2.67.xx.xx)=26, Qfactor=30, Pass=4.
I've tested to encode a short high motion clip of the film of 5000 frames with CCE 2.50 using the following settings : Bias=20, IQP=16, Qfactor=30, Pass=4. The result is about the same. Apparently, i can't get a better result. It's rather odd.
cya