IAMStreamConfig::GetNumberOfCapabilities method (strmif.h)

Article
02/22/2024

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 GetNumberOfCapabilities method retrieves the number of format capabilities that this pin supports.

Syntax

HRESULT GetNumberOfCapabilities(
  [out] int *piCount,
  [out] int *piSize
);

Parameters

[out] piCount

Pointer to a variable that receives the number of format capabilities.

[out] piSize

Pointer to a variable that receives the size of the configuration structure in bytes. See Remarks for more information.

Return value

Returns an HRESULT value. Possible values include the following.

Return code	Description
S_OK	Success.
E_POINTER	NULL pointer value.
VFW_E_NOT_CONNECTED	The input pin is not connected.

Remarks

An output pin can support more than one set of format capabilities. This method returns the total number of capabilities that the pin supports; the number is returned in the piCount parameter. To retrieve a particular set of capabilities, call the IAMStreamConfig::GetStreamCaps method. Format capabilities are indexed from zero, so the value returned in piCount is one more than the upper bound.

Depending on the pin's format type, the VIDEO_STREAM_CONFIG_CAPS structure (for video) or an AUDIO_STREAM_CONFIG_CAPS structure (for audio). The piSize parameter receives the size of the structure, in bytes.

On some compression filters, this method fails if the filter's input pin is not connected.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	strmif.h (include Dshow.h)
Library	Strmiids.lib