Quick Questions about using QuEnc

[Skunk]

I have been using DVD-RB for some time now and have had great success with using HC encoder for most DVDs. Sometimes I will use procoder, mostly for sources with alot of interleaving or CG stuff where the extra sharpness makes a big difference. Anyways, I have finally come across a DVD that I am not happy with the quality that either give me.
What I'm wondering is how do I get maximum quality from QuEnc? What are "use scene detection" and "trellis quantization" and should I use them? Remember, I am going for all out quality here so Im not too concerned with longer encode time.
Also, are there more ways I can customize QuEnc to tweak it a bit more?

[cobo]

From QuEnc_Settings.txt for v.54:

High Quality
------------
This slows down the encoder but gives higher quality. It is the same as using -mbd=2 in ffmpeg.If you only want high speed encoding, turn this off. But otherwise it is recommeneded to leave it on.

Use VBR
-------
This selects whether the bitrate should be allowed to fluctuate or to be a constant bitrate.
VBR will allow for better quality, but turning it off will allow CBR which is useful for streaming...(where you don't want to be the content to be bursty)

Scene Detection
---------------
If scene detection is on, then scene changes are detected and I-Frames are inserted. This can provide better use of GOPs. However, it can produce strange GOP sized. With Scene Detection off, the GOPs are now (as of 0.51) strictly enforced to use a strict GOP format. (i.e. it won't replace B-Frames with P-Frames in High motion)

Use Trellis Quant
-----------------
This greatly slows down the encoder but can give higher quality. Is only recommended when the quality of the encode is the most important thing.

"Extreme & Slow" Settings
-------------------------
This is experimental, not recommended, but turns on many settings that can increase quality but slow down the encoding alot.
The settings it turns on are as follows:
Trellis Quant
HQ
CBP Rate Distortion
MV0 (always try a MB with MV=<0,0>)
Change MB dicisions from SAD to SATD
luma elimination threshold = -4
chroma elimination threshold = -7
ratecontrol qsquish = 1
(These are subject to change ;) )

I use QuEnc59ß4 with "Extreme & Slow" settings checked for DVD's that run about 3 hours or more. The results seem slightly better than with just "Trellis Quant" and "High Quality" ticked, which in turn seems to me to produce slightly better results than using 5 passes of CCE. Also, I always use "Scene Detection" without any problem. Also always use 2pass VBR.

With "Extreme & Slow" settings checked my encoding time is usually about 12 hours per hour of video using a P4 2.66B (ranges from 8 to 13 hours per hour of video). With just "Trellis Quant" and "High Quality" ticked it takes half the time.

There's no option in RB for selecting "Extreme & Slow" settings - it needs to be ticked manually in QuEnc's "Advanced Options..." settings before RB starts the encoding phase. All other QuEnc options can be set through RB.

I've tried v.60 but the results seemed no better to me than using CCE, so I've stuck with v.59.