Begins an asynchronous request to write a media sample to the stream.
HRESULT BeginWriteSample( [in] IMFSample *pSample, [in] IMFAsyncCallback *pCallback, [in] IUnknown *punkState );
- pSample [in]
A pointer to the IMFSample interface of the sample.
- pCallback [in]
A pointer to the IMFAsyncCallback interface of a callback object. The caller must implement this interface.
- punkState [in]
A pointer to the IUnknown interface of a state object, defined by the caller. This parameter can be NULL. You can use this object to hold state information. The object is returned to the caller when the callback is invoked.
If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.
When the sample has been written to the stream, the callback object's IMFAsyncCallback::Invoke method is called. At that point, the caller should call IMFSampleOutputStream::EndWriteSample to complete the asynchronous request.
Minimum supported client
|Windows 8 [desktop apps | Windows Store apps]|
Minimum supported server
|Windows Server 2012 [desktop apps | Windows Store apps]|