The display mode has changed.
(IUnknown*) Pointer to an array of IPin interfaces for the video renderer's input pins. If lParam2 is zero, this parameter can be NULL.
If lParam2 is zero, lParam1 contains a single IPin pointer or equals NULL. If lParam2 is greater than zero, lParam1 contains an array of IPin pointers, and the number of elements in the array is given by lParam2.
The filter graph manager temporarily stops the graph, and then disconnects and reconnects the video renderer. It does not pass the event to the application.
Video renderers can send this event in response to a WM_DISPLAYCHANGE message. The WM_DISPLAYCHANGE message indicates that the user has changed the display resolution.
During pin connection, most video renderers pick a format based on the current display mode. If the display mode changes, the video renderer might need to choose another format. By sending this message, the renderer signals to the filter graph manager that it needs to be reconnected. During the reconnection, the renderer can select a new format. If the reconnection fails, the filter graph manager sends an EC_ERRORABORT event to the application.
A custom presenter for the Enhanced Video Renderer (EVR) should send this event to the EVR if the presenter's Direct3D device changes. Set lParam1 and lParam2 to zero; the EVR ignores the event parameters.