(How) Does AutoGk detect "burnt-in" Widescreen?

[kilivipin]

I am currently making a backup of MPD-Psycho. This video has an aspect ration of 4:3, but it is displayes a widescreen image,. What I mean by this is that the video has black bars on top and bottom which are "burnt-in", as apposed to an anamorphic transfer. I made a preview with AutoGK, and the black bars are gone, leaving just the video itself, in a 1.85 aspect ratio!
How does AutoGk detect this? Is this an intentional feature? Whatever it is, I love it!
I am using 1.93 beta, by the way.

[chilled]

I guess its the autocrop thing on the compressibility test uh?

[len0x]

It is indeed intended feature called "autocrop" :)

[chilled]

yes, err... thought that autocrop uses frames taken from the comptest avi. just guessing

[kilivipin]

Thanks. It is a really fantastic feature. I guess if those black bars remained, they would just use up valuable bits.

[chilled]

not many though (guess), as they would be encoded as two plain black rectangles...

[len0x]

It depends. If black-color border is inside an encoding block then it would take more bits than if it was just color block. That's why its always recommended to crop them away.

[obieobieobie]

Also, isn't it possible that the black borders can screw up the ratecontrol?