• Article

VideoSink.OnFormatChange Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

When overridden in a derived class, is invoked when a video device reports a video format change.

Namespace:  System.Windows.Media
Assembly:  System.Windows (in System.Windows.dll)

Syntax

'Declaration
Protected MustOverride Sub OnFormatChange ( _
    videoFormat As VideoFormat _
)

protected abstract void OnFormatChange(
    VideoFormat videoFormat
)

Parameters

Remarks

The current VideoFormat for a sink can differ from the format that is requested in VideoCaptureDevice.DesiredFormat.

When a video capture starts in the sink, OnFormatChange is invoked at least one time by the system for the first capture by that sink. Therefore, you can use OnFormatChange to determine current video format, instead of using DesiredFormat or SupportedFormats.

The VideoCaptureDevice properties help you determine whether your application logic can support capture and sample conversion for a particular device based on its formats. (You can also prompt users to change devices in their configuration UI if there are alternatives reported by GetAvailableVideoCaptureDevices that might work if the current default device is not supported.)

A format change from the video device (including getting the initial format of the capture) would typically also be relevant to your OnSample implementation.

Version Information

Silverlight

Supported in: 5, 4

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.