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IVideoProcAmp::get_DigitalMultiplier

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Microsoft DirectShow 9.0

IVideoProcAmp::get_DigitalMultiplier

This topic applies only to Windows XP Service Pack 2 and later.

The get_DigitalMultiplier method returns the camera's digital zoom level.

Syntax

  HRESULT get_DigitalMultiplier(
  long*  pValue,
  long*  pFlags
);

Parameters

pValue

[out]  Receives the digital zoom multiplier.

pFlags

[out]  Receives one or more flags. See VideoProcAmpFlags.

Return Values

Returns an HRESULT value.

Remarks

Digital zoom is applied after the image is captured. The effect of digital zoom is to multiply the optical magnification by a factor m, which can be calculated as follows:

m = ( (Z'cur - Z'min) * (m-max - 1) ) / (Z'max - Z'min) ) + 1

where

  • Z'cur = Current digital zoom level.
  • Z'min, Z'max = Minimum and maximum digital zoom. See IVideoProcAmp::getRange_DigitalMultiplier.
  • m-max = Maximum digital magnification. See KSPROPERTY_VIDEOPROCAMP_DIGITAL_MULTIPLIER_LIMIT, documented in the Windows DDK.

Requirements

Header: Include Vidcap.h.

Library: None.

See Also