CBaseInputPin class

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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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

The CBaseInputPin class is an abstract base class for implementing input pins. This class adds support for the IMemInputPin interface, in addition to the IPin interface support provided by CBasePin.

To use this class, derive a new class and override at least the following methods:

• CBaseInputPin::BeginFlush
• CBaseInputPin::EndFlush
• CBaseInputPin::Receive
• CBasePin::CheckMediaType
• CBasePin::GetMediaType

Depending on the function of the pin, you might need to override additional methods in CBaseInputPin or CBasePin.

Protected Member Variables	Description
m_pAllocator	Pointer to the memory allocator.
m_bReadOnly	Flag that indicates whether the allocator produces read-only media samples.
m_bFlushing	Flag that indicates whether the pin is currently flushing.
m_SampleProps	Properties of the most recent sample.
Public Methods	Description
CBaseInputPin	Constructor method.
~CBaseInputPin	Destructor method.
BreakConnect	Releases the pin from a connection.
IsReadOnly	Queries whether the allocator uses read-only media samples.
IsFlushing	Queries whether the filter is currently flushing.
CheckStreaming	Determines whether the pin can accept samples. Virtual.
PassNotify	Passes a quality-control message to the appropriate object.
Inactive	Notifies the pin that the filter is no longer active. Virtual.
SampleProps	Retrieves the properties of the most recent sample.
IPin Methods	Description
BeginFlush	Begins a flush operation.
EndFlush	Ends a flush operation.
IMemInputPin Methods	Description
GetAllocator	Retrieves the memory allocator proposed by this pin.
NotifyAllocator	Specifies an allocator for the connection.
GetAllocatorRequirements	Retrieves the allocator properties requested by the input pin.
Receive	Receives the next media sample in the stream.
ReceiveMultiple	Receives multiple samples in the stream.
ReceiveCanBlock	Determines whether calls to the CBaseInputPin::Receive method might block.
IQualityControl Methods	Description
Notify	Receives a quality-control message.

Requirements

Requirement	Value
Header	Amfilter.h (include Streams.h)
Library	Strmbase.lib (retail builds); Strmbasd.lib (debug builds)