CSource Class (Compact 2013)

3/26/2014

CBaseFilter Class

     CSource Class

This class and its corresponding class, CSourceStream, simplify the construction of source filters that produce continuous streams of data comparable to the way the CTransformFilter class assists in the creation of transform filters.

The CSource class provides a wrapper for the CBaseFilter class that performs the pin management and works with the CSourceStream class to provide the pins.

To use the CSource class to build a filter:

Derive your filter-level class from the CSource class. Provide a CreateInstance member function in it to create a new object of the class.

Provide a means of adding objects that are derived from the CSourceStream class to support the output pins during construction of the class. You can either create them yourself during construction or provide the developer with a means of creating them later.

For an example of using the CSource class, see the Ball sample in the Samples\Multimedia\DShow\Src\Ball subdirectory of the DirectX Media Software Development Kit (SDK).

This class does not help build an asynchronous file reader source filter, which requires support of an IAsyncReader interface and a downstream parser filter that supports the CPullPin class.

Protected Data Members

Member	Description
m_cStateLock	Locks this data member to serialize access to the filter state.
m_iPins	Number of pins on this filter; updated by the CSource::AddPin and CSource::RemovePin member functions.
m_paStreams	Array of streams associated with this filter.

Member Functions

Member function	Description
AddPin	Adds a pin to the source filter.
CSource	Constructs a CSource object.
FindPinNumber	Retrieves the number of the pin through the IPin parameter.
GetPin	Returns a pointer to a specified pin.
GetPinCount	Gets the number of pins contained by the filter.
pStateLock	Returns a pointer to the filter-critical section.
RemovePin	Removes a pin from the source filter.

Implemented IBaseFilter Methods

Method	Description
FindPin	Retrieves a pointer to the pin with the specified identifier.

Requirements

Header	dshow.h, Streams.h
Library	ole32.lib, Ole32auth.lib, Strmbase.lib, Strmiids.lib, uuid.lib

See Also

Reference

DirectShow Classes