# YV12InterlacedReduceBy2

## Abstract

author: Tom Barry
version: 0.1.0.0
download: http://mywebpages.comcast.net/trbarry/downloads.htm
category: Resizers
requirements:

- YV12 Colorspace
- SSEMMX (=ISSE) support

## Description

`YV12InterlacedReduceBy2` is a fast Reduce By 2 filter. It works by taking only the even (starting with 0) pixels from the top field. So it will reduce both the width and height by a factor of 2. It blends the chroma slightly to avoid YV12 chroma delay.

USAGE - To use it just:

1) Place the InterlacedReduceBy2.dll in a directory somewhere.
2) In your Avisynth file use commands similar to

    LoadPlugin("F:\YV12InterlacedReduceBy2\YV12InterlacedReduceBy2.dll")
    AviSource("D:\wherever\myfile.avi")
    YV12InterlacedReduceBy2()

Of course replace the file and directory names with your own. There are no parameters. This is usefull as a very fast downsize that needs no deinterlacing.

USAGE 2

There is a second similar function enclosed in the dll called YV12InterlacedSelectTopFields(). This will select top fields only and adjust for chroma delay but leave the width unchanged.

    LoadPlugin("F:\YV12InterlacedReduceBy2\YV12InterlacedReduceBy2.dll")
    Avisource("D:\wherever\myfile.avi")
    YV12InterlacedSelectTopFields()

`$Date: 2004/08/17 20:31:19 $`