separatefields duplicates pitch. Why?

[AVIL]

Hi,

Avisynth 2.5.8 (30.12.2008)

avisource("elige_fin.avi").info()

Info : Clip YUY2 width 752 pitch 1504

After separatefields:

avisource("elige_fin.avi").separatefields().info()

Info: Clip YUY2 width 752 pitch 3008

It's a bug or a feature?

[IanB]

separatefields() just recasts the pitch and bumps the start pointer for odd frames without actually changing any of the pixel data. That way it does the work for zero cost, i.e. with just pointer arithmetic.

There are quite a few filters like this.

[AVIL]

@IanB:

OK. Many thanks