IMemInputPin::Receive

  • Article
 
Microsoft DirectShow 9.0

IMemInputPin::Receive

The Receive method receives the next media sample in the stream.

Syntax

  HRESULT Receive(
  IMediaSample *pSample
);

Parameters

pSample

[in] Pointer to the sample's IMediaSample interface.

Return Values

Returns an HRESULT value. Possible values include those shown in the following table.

Return code Description
S_OK Success.
S_FALSE The sample was rejected.
E_POINTER NULL pointer argument.
VFW_E_INVALIDMEDIATYPE Invalid media type.
VFW_E_RUNTIME_ERROR A run-time error occurred.
VFW_E_WRONG_STATE The pin is stopped.

Remarks

This method is synchronous and possibly blocking. The pin does one of the following:

  • Rejects the sample.
  • Returns immediately and processes the sample in a worker thread.
  • Processes the sample before returning.

In the last case, the method might block indefinitely. If this might happen, the IMemInputPin::ReceiveCanBlock method returns S_OK.

If the pin uses a worker thread to process the sample, it holds a reference count on the sample. In any case, the output pin cannot directly re-use this sample. It must call the IMemAllocator::GetBuffer method to obtain a new sample.

If this method returns S_FALSE or an error code, the upstream filter should stop sending samples until the graph stops or completes a flush operation. Typical reasons for an S_FALSE return value include:

  • The downstream pin is flushing; that is, it received a BeginFlush call and has not yet received an EndFlush call.
  • The downstream filter detected the end of the stream. (See End-of-Stream Notifications.)

Requirements

Header: Declared in Strmif.h; include Dshow.h.

Library: Use Strmiids.lib.

See Also