x264 encoding options with MeGUI

[Ryu77]

I am in the midst of experimenting with x264 via MeGUI to refine my encoder settings. I have been encoding for quite some time and have been quite impressed with the results but I just got a bug to see if I can improve some settings. I am mainly concerned with quality vs. speed and how different settings affect these variables.

One setting I am unclear about in particular is the "Turbo" mode that MeGUI offers in the x264 configuration window. As the command line doesn't show any alteration, it is hard to discern what changes are made.

I have read through quite a lot of threads and posts found through google and I am still a little vague here.

Here is my x264 command line...

program --pass 2 --bitrate 8000 --stats "D:\Applications\MeGUI\x264 Log" --keyint 24 --min-keyint 1 --ref 4 --mixed-refs --no-fast-pskip --bframes 3 --b-adapt 2 --b-pyramid --weightb --direct auto --subme 9 --trellis 2 --partitions all --8x8dct --qpmin 8 --ipratio 1.1 --pbratio 1.1 --vbv-bufsize 15000 --vbv-maxrate 17500 --qcomp 0.5 --me tesa --threads auto --thread-input --progress --no-dct-decimate --no-psnr --no-ssim --output "output" "input" --mvrange 511 --aud --nal-hrd --sar 1:1

I would mainly like to know if any of the settings I have made become redundant through enabling turbo? If yes, which settings?

Also, what other settings are altered by enabling the turbo option?

[Kurtnoise]

From the code:

if (xs.Turbo)
{
xs.NbRefFrames = 1;
xs.SubPelRefinement = 1; // Q-Pel 2 iterations
xs.METype = 0; // diamond search
xs.I4x4mv = false;
xs.P4x4mv = false;
xs.I8x8mv = false;
xs.P8x8mv = false;
xs.B8x8mv = false;
xs.AdaptiveDCT = false;
xs.MixedRefs = false;
xs.X264Trellis = 0; // disable trellis
xs.noFastPSkip = false;
}

[Ryu77]

Thank you very much Kurtnoise... I think I read that (or something similar) somewhere earlier tonight.

I guess to clarify my question, are any of the settings that I have made in my command line dependent on those same settings being applied in the first pass? Do I need to enable these settings in both passes for it be effective?

This is what I meant by redundant. I would like to know if any of those settings are made useless by not being able to gain the required information from the first pass due to turbo mode.

[Sharktooth]

simple answer: no.

[Ryu77]

Thank you Kurtnoise and Sharktooth for prompt answers. I was experiencing extremely good results with MeGUI and x264 already and I recommend it exclusively for Blu-ray/AVCHD encoding over at AfterDawn.com. I just always had this nagging feeling that maybe I am missing something with the turbo option. Thank you for putting my mind at ease. :cool:

I have made a few profiles to help those newer on the scene to get straight into h264 encoding targeted for AVCHD or Blu-ray. Once again, thank you for your help.

BTW, if anyone is interested in using these profiles, here is a link: http://www.mediafire.com/file/zmhjvyo1mr1/Ryu77%20MeGUI%20x264%20Profiles.zip

[b66pak]

thanks for sharing...
_