CBaseOutputPin Class

Microsoft DirectShow 9.0

CBaseOutputPin Class

The CBaseOutputPin class is an abstract base class that implements an output pin.

This class derives from CBasePin. It differs from CBasePin in the following respects:

• It connects only to input pins that support the IMemInputPin interface.
• It supports local memory transport through the IMemAllocator interface.
• It rejects end-of-stream, flush, and new-segment notifications. (These should not be sent to an output pin.)
• It provides methods for delivering samples downstream.

When the pin connects, it requests a memory allocator from the input pin. Failing that, it creates a new allocator object. The output pin is responsible for setting the allocator properties. It does this through the pure virtual method CBaseOutputPin::DecideBufferSize. Override this method in your derived class. If the input pin has any buffer requirements, they are passed to the DecideBufferSize method.

Call the CBaseOutputPin::GetDeliveryBuffer method to obtain an empty media sample. Call the CBaseOutputPin::Deliver method to deliver samples downstream.

Your derived class must override the pure virtual CBasePin::CheckMediaType method to validate the media type during pin connections.

Requirements

**  Header:** Declared in Amfilter.h; include Streams.h.

**  Library:** Use Strmbase.lib (retail builds) or Strmbasd.lib (debug builds).

Protected Member Variables
m_pAllocator	Pointer to the memory allocator.
m_pInputPin	Pointer to the input pin connected to this pin.
Public Methods
CBaseOutputPin	Constructor method.
CompleteConnect	Completes a connection to an input pin. Virtual.
DecideAllocator	Selects a memory allocator. Virtual.
GetDeliveryBuffer	Retrieves a media sample that contains an empty buffer. Virtual.
Deliver	Delivers a media sample to the connected input pin. Virtual.
InitAllocator	Creates a memory allocator. Virtual.
CheckConnect	Determines whether a pin connection is suitable.
BreakConnect	Releases the pin from a connection.
Active	Notifies the pin that the filter is now active.
Inactive	Notifies the pin that the filter is no longer active.
DeliverEndOfStream	Delivers an end-of-stream notification to the connected input pin. Virtual.
DeliverBeginFlush	Requests the connected input pin to begin a flush operation. Virtual.
DeliverEndFlush	Requests the connected input pin to end a flush operation. Virtual.
DeliverNewSegment	Delivers a new-segment notification to the connected input pin. Virtual.
Pure Virtual Methods
DecideBufferSize	Sets the buffer requirements.
IPin Methods
BeginFlush	Begins a flush operation.
EndFlush	Ends a flush operation.
EndOfStream	Notifies the pin that no additional data is expected.