ISampleGrabber::SetCallback method

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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.]

Note

[Deprecated. This API may be removed from future releases of Windows.]

 

The SetCallback method specifies a callback method to call on incoming samples.

Syntax

HRESULT SetCallback(
   ISampleGrabberCB *pCallback,
   long             WhichMethodToCallback
);

Parameters

pCallback

Pointer to an ISampleGrabberCB interface containing the callback method, or NULL to cancel the callback.

WhichMethodToCallback

Index specifying the callback method. Must be one of the following values.

Value	Description
0	The Sample Grabber filter calls the ISampleGrabberCB::SampleCB method. This method receives an IMediaSample pointer.
1	The Sample Grabber filter calls the ISampleGrabberCB::BufferCB method. This method receives a pointer to the buffer that is contained in the media sample.

 

Return value

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

The data processing thread blocks until the callback method returns. If the callback does not return quickly, it can interfere with playback.

The filter does not invoke the callback function for preroll samples, or for samples in which the dwStreamId member of the AM_SAMPLE2_PROPERTIES structure is anything other than AM_STREAM_MEDIA.

Note

The header file Qedit.h is not compatible with Direct3D headers later than version 7.

 

Note

To obtain Qedit.h, download the Microsoft Windows SDK Update for Windows Vista and .NET Framework 3.0. Qedit.h is not available in the Microsoft Windows SDK for Windows 7 and .NET Framework 3.5 Service Pack 1.

 

Requirements

Requirement	Value
Header	Qedit.h
Library	Strmiids.lib

See also

Using the Sample Grabber

ISampleGrabber Interface