Microsoft Windows CE 3.0  

IEnumMediaTypes Interface

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The IEnumMediaTypesinterface enumerates the preferred formats for a pin.

When to Implement

This interface must be implemented and made available by the IPin::EnumMediaTypesmethod. The CBasePin::EnumMediaTypesmember function automatically does this in the Microsoft DirectShow class library and uses the CEnumMediaTypesclass to create the enumerator object.

When to Use

This interface is normally used by a connecting pin to determine the media type when negotiating a connection. It can also be passed through to other pins, either upstream or downstream of the filter, when intervening filters do not have a list of preferred media types. For example, a transform-inplace filter might pass the IEnumMediaTypesinterface of a downstream input pin to the connecting output pin of the upstream filter, instead of providing its own IEnumMediaTypesinterface.

Methods in Vtable Order

IUnknown methods Description
QueryInterface Returns pointers to supported interfaces.
AddRef Increments the reference count.
Release Decrements the reference count.
IEnumMediaTypes methods Description
Next Retrieves the specified number of items in the enumeration sequence.
Skip Skips a specified number of elements in the enumeration sequence.
Reset Resets the enumeration sequence to the beginning.
Clone Returns another enumerator containing the same enumeration state as the current one.