Make Video Fields

Quick Reference to Scripting Command
a=MAKEFIELDS(DOMINANCE, REPLACE)
Items in CAPS are 0/1 switches or switches with more options than 0/1.

This operation is designed primarily for timeline usage. The idea is that you have a series of full video resolution frames for either pal or NTSC as your action images. You have 60 of these, one for each field interval in the video stream.

The objective is to output a series of field resolution rather than frame resolution images, with the images taken from the correct odd or even set of scan lines. That's what this operator does - it extracts the correct scan lines from the correct full-frame, based on the odd or even position of the frame in the timeline. The resulting image has half of the scan lines (and so is a field image rather than a frame image.)

Sometimes, the odd/even parity of the images is switched, either because the sequence starts on an odd frame, or because the device you are feeding the images to requires odd lines first. In that case, change the state of the Field Dominance switch, and the fields will be generated in reverse order.

Tip: In order to generate animated sequences that are perfectly NTSC or PAL compatible, always generate the animation using the full frame resolution for the video standard you are working with. For instance, to generate a 1-second, proper NTSC field mode morph, you would set the output resolution to 768 x 482, and generate 60 frames. You would then take those 60 frames and "feed" them to this operator, which would generate the correct fields, 60 of them, from the 60 input frames. These fields would then be 768 x 241, correct for NTSC (for most hardware.) If the fields are reversed, remember, all you have to do is run the sequence again with the Field Dominance check in the other state. From now on, always run your conversions that way, and they should always be correct for your particular video encoding hardware.

Make Fields Controls

Field Dominance Switch

If your field conversion is reversed for any reason, so that the fields are produced in the wrong order, change the state of the checkmark and re-generate.

Replace Image

You need this checked for timeline operation, so that the output of the operator in the timeline is the new image. You can leave it unchecked in one-at-a-time operation if you want to keep the original full-frame intact.

WinImages F/x Manual Version 7, Revision 5, Level B