want AR Formula with crop

[DvdKhl]

Now please don't send me a reply with "rule 1" I have searched the Forum and found nothing! (maybe it's me :))

Now to business:
I have a
720x576 (4:3) Movie
I want to resize it to 400x304 (it has to be a mult of 16) obviusly that isn't 4:3.

So now i want a formula were I put the bottom&top crop in it and get the left&right crop.

I know I could use the calc from gknot but lets say it's for my personel intrest :)

[DJ Bobo]

It doesn't matter, just crop all black bars, and resize to a valid 4:3 format.
Better choose 384x288 or 448x336 by the way.

[Neo Neko]

Resizing to a multiple of 8 should work. I am not aware of what codec you are using that would require multiples of 16. In any case if you want perfect 4:3 aspect ratio near that size it is a simple matter.

You want near 400xXXX at 4:3 aspect ratio.
400/4=100 100/16=6.25

round 6.25 up or down to the nearest integer. 6 or 7.
[6*16=96 96*4=384 96*3=288 (384x288)]
[7*16=112 112*4=448 112*3=336(448x336)]

Those are your two perfect choices to resize to 4:3 at a multiple of 16. Then you can crop or not and you are done.

[DvdKhl]

thx for your replys!
and thx again @ Neo Neko
after you wrote that the mult of 8 shuold work I tried it and it worked. Now it's easier to pick a good res.

[Didée]

Originally posted by Neo Neko
Resizing to a multiple of 8 should work. I am not aware of what codec you are using that would require multiples of 16.
Some time ago, I compared encoding of mod8 and mod16 resolutions with XviD. I found that mod8 gives a ~3% compression penalty.