IKsTopologyInfo::get_NumCategories method (vidcap.h)

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The get_NumCategories method returns the number of categories for this filter.

Syntax

HRESULT get_NumCategories(
  [out] DWORD *pdwNumCategories
);

Parameters

[out] pdwNumCategories

Receives the number of categories.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code Description
S_OK
The method succeeded.

Requirements

Requirement Value
Minimum supported client Windows XP with SP2 [desktop apps only]
Minimum supported server Windows Server 2003 R2 [desktop apps only]
Target Platform Windows
Header vidcap.h

See also

Error and Success Codes

IKsTopologyInfo Interface