IAMVideoAccelerator::GetUncompFormatsSupported method (videoacc.h)

Article
4/26/2023

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 GetUncompFormatsSupported method gets a list of uncompressed pixel formats that can be rendered using a specified DirectX Video Acceleration (DXVA) profile.

Syntax

HRESULT GetUncompFormatsSupported(
  [in]      const GUID      *pGuid,
  [in, out] LPDWORD         pdwNumFormatsSupported,
  [in, out] LPDDPIXELFORMAT pFormatsSupported
);

Parameters

[in] pGuid

Pointer to a GUID that specifies the DXVA profile. To get a list of supported profiles, call IAMVideoAccelerator::GetVideoAcceleratorGUIDs.

[in, out] pdwNumFormatsSupported

On input, specifies the number of elements in the pFormatsSupported array. If pFormatsSupported is NULL, the value of *pdwNumFormatsSupported must be zero.

On output, if pFormatsSupported is NULL, pdwNumFormatsSupported receives the number of supported pixel formats. Otherwise, pdwNumFormatsSupported receives the actual number of pixel formats copied to the pFormatsSupported array.

[in, out] pFormatsSupported

Address of an array of DDPIXELFORMAT structures, or NULL. If the value is non-NULL, the array receives a list of pixel formats.

Return value

This method can return one of these values.

Return code	Description
DDERR_MOREDATA	The method returned fewer formats than the total number that are supported, because the array was too small. Although this value is a failure code, you can ignore the error if you intentionally allocated a smaller array.
S_OK	The method succeeded.

Remarks

Call this method twice. On the first call, set pFormatsSupported to NULL. The pdwNumFormatsSupported parameter receives the number of formats. Allocate an array of DDPIXELFORMAT structures with the required size, and call the method again. This time, set pFormatsSupported to the address of the array. The method fills the array with the list of pixel formats.

The driver should return the formats in decreasing order of preference, with the most preferred format listed first.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	videoacc.h
Library	Strmiids.lib

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