1-pass quality based encoding

[Marcus Halberstam]

Hello!

I've used Gordian Knot for quite a while now, and I am very pleased with the resulting video files. But now I got a DVD burner, so I get about three movies (quality at ~60%) on one DVD, and for the first two of them the size is not that important anymore. (It would be enough to specify that for the last one depending on the space left on the disk.)

I figure I can skip the second encoding pass, if I could set DivX to quality-based encoding, can't I?

The question would be, how I can achieve that within Gordian Knot, since the rest of GK is still very handy, like the letterbox cropping, frameserving, etc., and I don't have a clue how to encode outside GK, because I've never done that! :)

I just want one pass quality encoding!

Thanks!

Markus

[manono]

Hi-

I can think of a couple of ways to achieve what you want. This is DivX, right? One is to use AutoGK. However, a lot of the choices that you may want to make will be taken out of your hands. But you can do a 1-pass Quality Mode, choosing 60% and the horizontal resolution. It's real easy, real good, and may fit your needs:

http://forum.doom9.org/showthread.php?s=&threadid=64266

The other is to use GKnot for everything up to the actual encoding. Crop, resize, add the filters you want, create the .avs, etc. Then open the saved .avs in VDubMod, choose the DivX codec in Video->Compression, and following the DivX guide for 1-pass quality mode, you'll get what you want. You can mux the audio during the encoding or afterwards. Here's the Guide:

http://www.divx.com/support/divx/guide.php

About a third of the way down it says:
1-Pass Quality Based Mode: The encoder will code everything with the same absolute quality without giving respect to the amount of motion. This mode is accessible after de-activating the enforcement of DivX Certified profiles. When using this mode all frames receive the same amount of compression, without regard to their complexity. While it is not the best choice for making archives, it is a good idea to use this mode when preparing content for future editing. This feature guarantees the preservation of quality in all frames. When selecting the "Quality Based" mode the slider will adjust the Quantizer on a percentage basis while showing the exact number that will be used to compress each frame.
If you want around 60%, then (I think) you'll choose an average quant of 3-3.2 or so.

GKnot itself is for 2-pass encoding, so you won't be able to do the whole thing entirely from within GKnot.

[Marcus Halberstam]

Hello,

thanks a lot for that advice! I just gave autoGK a try, and the result seems to be fine. Two questions, though:

Is the compression/gain for the audio comparable to the "-c normal" parameter for azid? I wouldn't like more compression than that. (oops - I just found out about that. It is indeed the normal setting. next.)

And: the DivX setting I can only guess, right? Timewise it seems to be standard encoding; is the psycho-thing switched to 'fast'? I always do that... and I use B-frames and GMC too. I couldn't find any information about that.

Apart from that - I may use this tool for all rips, why not!


Markus

[manono]

Hi-

One of the reasons for the development of AutoGK was to make .avis that are compatible with standalone DVD/MPEG-4 players. So, no GMC. It does use B-Frames. I'm guessing on the Psychovisual Enhancements, but I'd say no. len0x or someone else will know the answer to that one.

[Marcus Halberstam]

It would be PERFECT if I could bring AutoGK to use GMC; I watch my movies using a TV-out, so standard player support is not crucial for me...

Marcus

[len0x]

Bframes - yes
GMC - no
Psycho - no

It wouldn't be AutoGK if I'd allow manual codec settings :)