Vertical Interlacing?
by Sondra Selhorn
on
Jan 11, 2008 at 5:26:42 pm
I know this sounds a bit strange but does anyone know an easy way to interlace footage vertically in After Effects (CS3)? Right now I am forced to flip the footage sideways, interlace horizontally, and then flip it back. I am wondering if there is some easier way that I am just not aware of or if there is a plugin that may be helpful. Thanks.
Re: Vertical Interlacing? by Kevin Camp on Jan 11, 2008 at 5:45:32 pm
if it is footage that was shot at either 60p (59.95 fps) or 60i (standard 29.97 interlaced) you could create a comp that is 59.94 fps then bring the footage in.
create a screen of vertical 1 pixel lines with 1 pixel spacing (i imght do this in photoshop, but you could use a solid and the grid effect, etc) to use as a track matte to generate vertical scan lines.
so you have a comp with your footage and a vertical line screen layer. if the footage is 60p you're ready for the next step, if it is 60i make sure that ae is set to separate fields correctly (select the footage in the proejct window and choose file>interpret footage>main) and probably check the preserve edges box. now the 29.97 footage will appear like 60p footage.
duplicate the footage in the comp and offset it by one frame, then choose to use the vertical line layer as a track matte.
this should now create vertical interlacing where even lines are off set by a 60th of a second to the odd lines at a frame rate of 30 fps (29.97). now you can render to 29.97 (no field render option, they already there), or take to another comp for what ever you are using this for....
and i have to ask, what are you using this for...?
note -- i gave ntsc frame rates, but this should also work for pal... 25 fps (50 interlaced) or 50p.
Re: Vertical Interlacing? by Dave LaRonde on Jan 11, 2008 at 6:04:31 pm
Hmmmm...... I have to wonder why you even need to do this.
If you import interlaced footage into AE and interpret the field order properly, you're all set. If you then in turn render an AE comp using that footage -- in the proper field order, of course -- it will be just fine, even if you rotate the footage 90 degrees in your AE comp.
It's all a matter of interpreting and rendering in proper field order. I'm scratchin' my head trying to figure out why you'd need to do anything else, and I'm not comin' up with any good reasons.
Re: Vertical Interlacing? by Kevin Camp on Jan 11, 2008 at 6:23:33 pm
yep.... if this is for a monitor that will be mounted vertically, i would work with a vertical comp until i went to render, then i'd drop it into a standard comp, rotate it and render (with fields if necessary). if all of the footage was interpreted to correctly separate fields, then all should be good in the end.
but maybe this is for some other effect or purpose. i'm pretty curious about the purpose....
