IFilterInfo Interface

IFilterInfo is an interface that manages information about a filter and provides access to the filter and to the IPinInfo interfaces representing the pins on the filter. It is essentially an IBaseFilter interface that can be accessed through Automation. This was created to provide access to the IBaseFilter methods from Microsoft® Visual Basic® applications without incurring the overhead of Automation in the IBaseFilter interface itself.

When to Implement

This interface is implemented by the filter graph manager for use by Automation client applications, such as Microsoft Visual Basic.

When to Use

Use this interface from an application to retrieve information about a filter and to retrieve individual pin objects in the filter or a collection of all pin objects belonging to the filter. This can be used when adding filters to a filter graph and connecting pins together.

Methods in Vtable Order

IUnknown methods	Description
QueryInterface	Returns pointers to supported interfaces.
AddRef	Increments the reference count.
Release	Decrements the reference count.

IDispatch methods	Description
GetTypeInfoCount	Determines whether there is type information available for this dispinterface.
GetTypeInfo	Retrieves the type information for this dispinterface if GetTypeInfoCount returned successfully.
GetIDsOfNames	Converts text names of properties and methods (including arguments) to their corresponding DISPIDs.
Invoke	Calls a method or accesses a property in this dispinterface if given a DISPID and any other necessary parameters.

IFilterInfo methods	Description
FindPin	Locates a pin and returns an IPinInfo interface.
get_Name	Retrieves the filter name.
get_VendorInfo	Retrieves a string containing optional information supplied by a vendor about the specified filter.
get_Filter	Retrieves the IBaseFilter interface for the filter.
get_Pins	Retrieves an IAMCollection interface which provides access to the IPinInfo interfaces for this filter.
get_IsFileSource	Determines if the filter is a file source filter.
get_Filename	Retrieves the file name associated with the source filter.
put_Filename	Sets the file name containing the media source.

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IFilterInfo::FindPin

IFilterInfo Interface

Locates a pin, given an identifier, and returns an IPinInfo interface.

HRESULT FindPin(
  BSTR strPinID,
  IDispatch **ppUnk
  );

Parameters

strPinID

[in] String pin identifier.

ppUnk

[out] IPinInfo interface.

Return Values

Returns an HRESULT value.

Remarks

This method corresponds to the IBaseFilter::FindPin method. This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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IFilterInfo::get_Filename

IFilterInfo Interface

Retrieves the file name associated with the source filter.

HRESULT get_Filename(
  BSTR *pstrFilename
  );

Parameters

pstrFilename

[out, retval] File name containing the source media.

Return Values

Returns an HRESULT value.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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IFilterInfo::get_Filter

IFilterInfo Interface

Retrieves the IBaseFilter interface of the filter.

HRESULT get_Filter(
  IUnknown **ppUnk
  );

Parameters

ppUnk

[out, retval] IBaseFilter interface of the filter represented by IFilterInfo.

Return Values

Returns an HRESULT value.

Remarks

The object that implements IFilterInfo is a wrapper and is not the same COM object as the filter itself. Thus a call to IFilterInfo::QueryInterface for IBaseFilter will fail. The IFilterInfo::get_Filter method allows an application to obtain the filter object itself. This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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IFilterInfo::get_IsFileSource

IFilterInfo Interface

Determines if the filter is a file source filter.

HRESULT get_IsFileSource(
  LONG *pbIsSource
  );

Parameters

pbIsSource

[out, retval] Returned Boolean value.

Return Values

Returns an HRESULT value. Returns OATRUE if filter is a file source filter; otherwise, returns OAFALSE.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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IFilterInfo::get_Name

IFilterInfo Interface

Retrieves the filter name.

HRESULT get_Name(
  BSTR *strName
  );

Parameters

strName

[out, retval] Name of the filter.

Return Values

Returns an HRESULT value.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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IFilterInfo::get_Pins

IFilterInfo Interface

Retrieves an IAMCollection interface, which provides access to the IPinInfo interfaces for the pins on this filter.

HRESULT get_Pins(
  IDispatch **ppUnk
  );

Parameters

ppUnk

[out, retval] IAMCollection interface.

Return Values

Returns an HRESULT value.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations. Visual Basic applications can enumerate the IPinInfo interfaces in the returned IAMCollection object by using the For Each ...Next syntax.

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IFilterInfo::get_VendorInfo

IFilterInfo Interface

Retrieves a string containing optional information supplied by a vendor about the specified filter.

HRESULT get_VendorInfo(
  BSTR *strVendorInfo
  );

Parameters

strVendorInfo

[out, retval] String containing vendor information.

Return Values

Returns an HRESULT value.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

---

IFilterInfo::put_Filename

IFilterInfo Interface

Sets the file name containing the media source.

HRESULT put_Filename(
  BSTR strFilename
  );

Parameters

strFilename

[in] Name of the file for the source filter to read from.

Return Values

Returns an HRESULT value.

Remarks

This method is exposed for use by Automation clients and is not expected to be used by C or C++ applications because of performance limitations.

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