CBaseControlVideo.GetVideoPaletteEntries method

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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 GetVideoPaletteEntries method retrieves a range of palette entries for the video.

Syntax

HRESULT GetVideoPaletteEntries(
   long StartIndex,
   long Entries,
   long *pRetrieved,
   long *pPalette
);

Parameters

StartIndex: Zero-based start palette entry.
Entries: Number of entries required.
pRetrieved: Pointer to the number of colors obtained.
pPalette: Pointer to output buffer for colors.

Return value

Returns NOERROR if successful, VFW_E_NO_PALETTE_AVAILABLE if the video samples has no color palette, E_OUTOFMEMORY if there is not enough memory available, E_INVALIDARG if StartIndex is invalid, or S_FALSE if there are no colors in the palette.

Remarks

This member function returns the current palette of the video as an array allocated by the user. To remain consistent, use the members in the Win32 PALETTEENTRY structure to return the colors, rather than the members in the RGBQUAD structure (although the parameter is a LONG). The memory is allocated by the caller, so simply copy each in turn. Determine that the number of entries requested and the start position offset are both valid. If the number of entries evaluates to zero, return an S_FALSE code.

Requirements

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