Zoom Method

Microsoft DirectShow 9.0

Zoom Method

This component is available for use in the Microsoft Windows 2000, Windows XP, and Windows Server 2003 operating systems. It may be altered or unavailable in subsequent versions.

The Zoom method zooms the video display in or out, centered on a given set of screen coordinates.

Syntax

  MSWebDVD
  .Zoom(
  iXPos
  , iYPos, iZoomRatio);

Parameters

iXPos

Specifies the x-coordinate at the center of the rectangular zoom area as an Integer.

iYPos

Specifies the y-coordinate at the center of the rectangle to be zoomed as an Integer.

iZoomRatio

Specifies the magnification factor applied to the current zoom value as an Integer. The total maximum value depends on what the hardware overlay can support; this is typically a factor of 32 to 64 times the original size.

Return Values

No return value.

Remarks

The new zoom ratio stays in effect until it is restored to the original size or changed again. In other words, two calls to this method specifying an iZoomRatio of two will result in a zoom ratio four times larger than the original video size. If the user tries to zoom beyond what the hardware can support, this method will succeed but do nothing.

The SetClipVideoRect method is another way to zoom in; the only difference between the two methods is the way in which the zoom rectangle is specified.