EC_DISPLAY_CHANGED

Article
07/27/2023

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The display mode has changed.

Parameters

lParam1: (IUnknown*) Pointer to an array of IPin interfaces for the video renderer's input pins. If lParam2 is zero, this parameter can be NULL.
lParam2: 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.

Default Action

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.

Remarks

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.

Enhanced Video Renderer

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.

Requirements

Requirement	Value
Header	Dshow.h