ICodecAPI::GetParameterRange method

The GetParameterRange method gets the range of values for a codec property.

This method applies only to properties whose values form a linear range.

Syntax

HRESULT GetParameterRange(
  [in]  const GUID    *Api,
  [out]       VARIANT *ValueMin,
  [out]       VARIANT *ValueMax,
  [out]       VARIANT *SteppingDelta
);

Parameters

Api [in]

Pointer to a GUID that specifies the property to query. For a list of standard codec properties, see Codec API Properties.

ValueMin [out]

Pointer to a VARIANT that receives the minimum value of the property. The caller must free the VARIANT by calling VariantClear.

ValueMax [out]

Pointer to a VARIANT that receives the maximum value of the property. The caller must free the VARIANT by calling VariantClear.

SteppingDelta [out]

Pointer to a VARIANT that receives the stepping delta, which defines the valid increments from ValueMin to ValueMax. The caller must free the VARIANT by calling VariantClear.

If the VARIANT type is VT_EMPTY, any increment is valid.

Return value

This method can return one of these values.

Remarks

The valid range for the property is [ValueMin... ValueMax], with increments of SteppingDelta. If a property supports a linear range of values, the property must use one of the following variant types:

• Unsigned types: VT_UI8, VT_UI4, VT_UI2, VT_UI1
• Signed types: VT_I8, VT_I4, VT_I2
• Floating-point types: VT_R8, VT_R4

If the property supports a list of values, instead of a range, the method returns VFW_E_CODECAPI_ENUMERATED. In that case, call ICodecAPI::GetParameterValues to get the list of values.

Requirements

See also

Codec API Reference

ICodecAPI

Encoder API