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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 |
|
| Library |
|
See also