Edit

CImageDisplay class

  • Article

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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.]

cimagedisplayclasshierarchy

The CImageDisplay class is a helper class for GDI video renderers to manage the display format. The object stores a VIDEOINFO structure that describes the current display mode, which is initialized in the object's constructor method. The object's CheckMediaType method checks whether a proposed media type can be rendered efficiently using GDI.

Protected Member Variables Description
m_Display VIDEOINFO structure that describes the current display format.
Protected Methods Description
CheckBitFields Validates the color masks in a VIDEOINFO structure.
CountPrefixBits Calculates the number of zero bits at the start of a specified bit field.
CountSetBits Returns the number of bits set to 1 in a specified bit field.
Public Methods Description
CheckHeaderValidity Validates a BITMAPINFOHEADER structure.
CheckMediaType Determines whether a proposed media type is compatible with the display format.
CheckPaletteHeader Validates the palette entries in a VIDEOINFO structure.
CheckVideoType Checks whether a specified VIDEOINFO format is compatible with the display format.
CImageDisplay Constructor method.
GetBitMasks Retrieves the color masks for a specified VIDEOINFO format.
GetColourMask Retrieves the color masks for the current display format.
GetDisplayDepth Retrieves the bit depth of the current display mode.
GetDisplayFormat Retrieves a video format that describes the current display mode.
IsPalettised Retermines whether the current display format is palettized.
RefreshDisplayType Updates the object's video format to match the specified display

Requirements

Requirement Value
Header
Winutil.h (include Streams.h)
Library
Strmbase.lib (retail builds);
Strmbasd.lib (debug builds)