IMediaParamInfo::GetParamText

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Microsoft DirectShow 9.0

IMediaParamInfo::GetParamText

The GetParamText method retrieves a series of text strings that describe the parameter.

Syntax

  HRESULT GetParamText(
    DWORD dwParamIndex,
    WCHAR **ppwchText
);

Parameters

dwParamIndex

[in] Zero-based index of the parameter.

ppwchText

[out] Address of a variable that receives a pointer to a series of Unicode™ strings.

Return Values

Returns an HRESULT value. Possible values include the following.

Return Code Description
E_INVALIDARG Index out of range.
E_POINTER NULL pointer argument.
S_OK Success.

Remarks

If the method succeeds, *ppwchText points to a string with the following format:

Name\0Unit\0Enum1\0Enum2\0...EnumN\0\0

where

  • Name is the name of the parameter.
  • Unit is the name of the units; for example, milliseconds.
  • Enum1 through EnumN are descriptive names for the parameter's enumerated values. (Applies only to parameters of type MPT_ENUM.)

The application can display these values within its user interface. They are not guaranteed to follow a consistent naming scheme. If the user's computer is using an international code page, the method might return a localized string corresponding to that code page.

The object uses the CoTaskMemAlloc function to allocate memory for the string. After you call this method, call CoTaskMemFree to free the buffer.

Requirements

  Header: Medparam.h
  Library: Dmoguids.lib.

See Also