IKsInterfaceHandler interface (ksproxy.h)

The IKsInterfaceHandler interface provides methods that marshal samples into the kernel based on the KSPIN_INTERFACE structure specified for the established connection. The IID for this interface is IID_IKsInterfaceHandler.

Inheritance

The IKsInterfaceHandler interface inherits from the IUnknown interface.

Methods

The IKsInterfaceHandler interface has these methods.

IKsInterfaceHandler::KsCompleteIo The KsCompleteIo method cleans up extended headers and releases media samples after input and output (I/O) complete.
IKsInterfaceHandler::KsProcessMediaSamples The KsProcessMediaSamples method processes media samples.
IKsInterfaceHandler::KsSetPin The KsSetPin method informs the streaming interface handler about the pin with which to communicate when passing data.

Remarks

In order to keep the proxy neutral with regard to the interface used to stream data, interface handlers are loaded to translate DirectShow media samples to and from a kernel-level driver. An interface handler implements the methods of the IKsInterfaceHandler interface to perform preprocessing and postprocessing on all media samples and to signal the completion of input and output (I/O).

Each interface handler can marshal media samples using its own method. The standard interface handler that KS proxy implements uses IOCTL_KS_WRITE_STREAM for the receive operation and IOCTL_KS_READ_STREAM for the send operation, but a custom interface handler can use some other method.

When a pin is connected, the proxy uses the GUID in the Set member of the KSPIN_INTERFACE structure to determine what interface handler to load. The interface handler is registered as a COM server under that GUID class. The interface handler must handle all variations of the interface within the interface set. Bridge pins are not expected to stream data, and interface handlers are not loaded for them.

On an interface handler create request through CoCreateInstance, the server is always presented an outer IUnknown with which to create the COM object. This IUnknown is an interface on the pin object that is loading this interface handler. The IUnknown interface pointer can be used to query information or interfaces, such as the IKsControl interface, from the pin, although the kernel-mode pin may not have been created at the time the interface handler is loaded. No reference should be left on the outer object through acquiring any interfaces, as it will result in a circular reference count. Using the interfaces without a reference count is acceptable, because the outer object owns the handler and, by definition, is destroyed when the outer object's reference count reaches zero.

Requirements

Requirement	Value
Target Platform	Windows
Header	ksproxy.h

See also

CoCreateInstance

IKsControl

KSPIN_INTERFACE