IEnumMediaTypes Interface
This interface enumerates the preferred formats for a pin.
When to Implement
This interface must be implemented and made available by the IPin::EnumMediaTypes method. The CBasePin::EnumMediaTypes member function automatically does this in the DirectShow class library and uses the CEnumMediaTypes class 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 IEnumMediaTypes interface of a downstream input pin to the connecting output pin of the upstream filter, instead of providing its own IEnumMediaTypes interface.
Methods in Vtable Order
The following table shows the methods that appear in the Vtable beneath the standard COM methods inherited from IUnknown.
| Method | 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. |
Requirements
DirectShow applications and DirectShow filters have different include file and link library requirements. See Setting Up the Build Environment for more information.
OS Versions: Windows CE 2.12 and later. Version 2.12 requires DXPAK 1.0 or later.
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Last updated on Wednesday, April 13, 2005
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