IEnumPins::Next method (strmif.h)

Article
07/27/2023

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 Next method retrieves a specified number of pins in the enumeration sequence.

Syntax

HRESULT Next(
  [in]  ULONG cPins,
  [out] IPin  **ppPins,
  [out] ULONG *pcFetched
);

Parameters

[in] cPins

Number of pins to retrieve.

[out] ppPins

Array of size cPins that is filled with IPin pointers. The caller must release the interfaces.

[out] pcFetched

Pointer to a variable that receives the number of pins retrieved. Can be NULL if cPins is 1.

Return value

Returns one of the following HRESULT values.

Return code	Description
S_FALSE	Did not retrieve as many pins as requested.
S_OK	Success.
E_INVALIDARG	Invalid argument.
E_POINTER	NULL pointer argument.
VFW_E_ENUM_OUT_OF_SYNC	The filter's state has changed and is now inconsistent with the enumerator.

Remarks

This method retrieves pointers to the specified number of pins, starting at the current position in the enumeration, and places them in the specified array.

If the method succeeds, the IPin pointers all have outstanding reference counts. Be sure to release them when you are done.

If the number of pins changes, the enumerator is no longer consistent with the filter, and the method returns VFW_E_ENUM_OUT_OF_SYNC. Discard any data obtained from previous calls to the enumerator, because it might be invalid. Update the enumerator by calling the IEnumPins::Reset method. You can then call the Next method safely.

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