DAR for 720 x 432 anamorphic encodes in MeGui

[aguy]

Hi there.

Just a quick question about DAR.

I am encoding Star Wars Attack of the Clones with Megui and x264. I want to encode anamorphically without resizing. My source is PAL DVD.

After cropping I am left with an image 720 x 432.

If I tick "Maintain Resolution and set AR in encoder" in Megui and don't resize then it sets the AR at 47:20 in the x264 encoder config page. This equates to a DAR of 2.35:1

However doing the maths the DAR should really be 2.37:1. (720 wide gets expanded to 1024 with a PAR of 64:45 and 1024/432 equals 2.37:1). The simplified fraction for 1024/432 is 64/27.

What do people think. Should I leave the AR in the x264 config page at 47:20 (which gives an image 1015 x 432) or manually change it to 64:27 which would give the 1024 x 432 image again.

BTW I know that the Sample Aspect Ratio in config page should be labelled DAR.

Thanks

[berrinam]

2.37 / 2.35 = 1.008
which gives an aspect error of 0.008 = 0.8%. This isn't really much to be concerned about.

[aguy]

Fair enough berrinam. I appreciate your advice.

I just tend to be picky about doing things properly (often to my own detriment).

[berrinam]

Well, if doing it 'properly' is important to you, then it's not overly much work to adjust the AR value somewhere... I would say that the best place to do that is to modify the two values in the AviSynth script: MeGUI_darx and MeGUI_dary, but you could also do it in the codec config dialog once you have opened your AviSynth script in the main window.

I'm working on a few updates to MeGUI's AR handling at the moment, which will give you more flexibility in these regards...

[aguy]

'Properly' wasn't really the best word. I always take note of what you have written Berrinam.

Really just wondering what different people would tend to do. Encode with a DAR of 47:20 or 64:27?

[berrinam]

You can configure the maximum aspect errror you will put up with in the settings. Since 0.2.3.2129, this also works with anamorphic encodes.

[delacroixp]

Getting it right is always nice...

:):D:eek:
Pascal