DXVA2_VideoDesc structure

Describes a video stream for a DXVA decoder device or video processor device.


typedef struct _DXVA2_VideoDesc {
  UINT                 SampleWidth;
  UINT                 SampleHeight;
  DXVA2_ExtendedFormat SampleFormat;
  D3DFORMAT            Format;
  DXVA2_Frequency      InputSampleFreq;
  DXVA2_Frequency      OutputFrameFreq;
  UINT                 UABProtectionLevel;
  UINT                 Reserved;
} DXVA2_VideoDesc;



Width of the video frame, in pixels.


Height of the video frame, in pixels.


Additional details about the video format, specified as a DXVA2_ExtendedFormat structure.


Surface format, specified as a D3DFORMAT value or FOURCC code. A FOURCC code can be constructed using the D3DFORMAT or MAKEFOURCC macros.


Frame rate of the input video stream, specified as a DXVA2_Frequency structure.


Frame rate of the output video, specified as a DXVA2_Frequency structure.


Level of data protection required when the user accessible bus (UAB) is present. If TRUE, the video must be protected when a UAB is present. If FALSE, the video is not required to be protected.


Reserved. Must be zero.


The InputSampleFreq member gives the frame rate of the decoded video stream, as received by the video renderer. The OutputFrameFreq member gives the frame rate of the video that is displayed after deinterlacing. If the input video is interlaced and the samples contain interleaved fields, the output frame rate is twice the input frame rate. If the input video is progressive or contains single fields, the output frame rate is the same as the input frame rate.

Decoders should set the values of InputSampleFreq and OutputFrameFreq if the frame rate is known. Otherwise, set these members to 0/0 to indicate an unknown frame rate.


The following code converts a Media Foundation media type, represented using the IMFMediaType interface, into a DXVA2_VideoDesc structure.

// Fills in the DXVA2_ExtendedFormat structure.
void GetDXVA2ExtendedFormatFromMFMediaType(
    IMFMediaType *pType, 
    DXVA2_ExtendedFormat *pFormat
    // Get the interlace mode.
    MFVideoInterlaceMode interlace = 
            pType, MF_MT_INTERLACE_MODE, MFVideoInterlace_Unknown

    // The values for interlace mode translate directly, except for mixed 
    // interlace or progressive mode.

    if (interlace == MFVideoInterlace_MixedInterlaceOrProgressive)
        // Default to interleaved fields.
        pFormat->SampleFormat = DXVA2_SampleFieldInterleavedEvenFirst;
        pFormat->SampleFormat = (UINT)interlace;

    // The remaining values translate directly.
    // Use the "no-fail" attribute functions and default to "unknown."
    pFormat->VideoChromaSubsampling = MFGetAttributeUINT32(
        pType, MF_MT_VIDEO_CHROMA_SITING, MFVideoChromaSubsampling_Unknown);

    pFormat->NominalRange = MFGetAttributeUINT32(
        pType, MF_MT_VIDEO_NOMINAL_RANGE, MFNominalRange_Unknown);

    pFormat->VideoTransferMatrix = MFGetAttributeUINT32(
        pType, MF_MT_YUV_MATRIX, MFVideoTransferMatrix_Unknown);

    pFormat->VideoLighting = MFGetAttributeUINT32(
        pType, MF_MT_VIDEO_LIGHTING, MFVideoLighting_Unknown);

    pFormat->VideoPrimaries = MFGetAttributeUINT32(
        pType, MF_MT_VIDEO_PRIMARIES, MFVideoPrimaries_Unknown);

    pFormat->VideoTransferFunction = MFGetAttributeUINT32(
        pType, MF_MT_TRANSFER_FUNCTION, MFVideoTransFunc_Unknown);


HRESULT ConvertMFTypeToDXVAType(IMFMediaType *pType, DXVA2_VideoDesc *pDesc)
    ZeroMemory(pDesc, sizeof(*pDesc));

    GUID                    subtype = GUID_NULL;
    UINT32                  width = 0;
    UINT32                  height = 0;
    UINT32                  fpsNumerator = 0;
    UINT32                  fpsDenominator = 0;

    // The D3D format is the first DWORD of the subtype GUID.
    HRESULT hr = pType->GetGUID(MF_MT_SUBTYPE, &subtype);
    if (FAILED(hr))
        goto done;

    pDesc->Format = (D3DFORMAT)subtype.Data1;

    // Frame size.
    hr = MFGetAttributeSize(pType, MF_MT_FRAME_SIZE, &width, &height);
    if (FAILED(hr))
        goto done;

    pDesc->SampleWidth = width;
    pDesc->SampleHeight = height;

    // Frame rate.
    hr = MFGetAttributeRatio(pType, MF_MT_FRAME_RATE, &fpsNumerator, &fpsDenominator);
    if (FAILED(hr))
        goto done;

    pDesc->InputSampleFreq.Numerator = fpsNumerator;
    pDesc->InputSampleFreq.Denominator = fpsDenominator;

    // Extended format information.
    GetDXVA2ExtendedFormatFromMFMediaType(pType, &pDesc->SampleFormat);

    // For progressive or single-field types, the output frequency is the same as
    // the input frequency. For interleaved-field types, the output frequency is
    // twice the input frequency.  
    pDesc->OutputFrameFreq = pDesc->InputSampleFreq;

    if ((pDesc->SampleFormat.SampleFormat == DXVA2_SampleFieldInterleavedEvenFirst) ||
        (pDesc->SampleFormat.SampleFormat == DXVA2_SampleFieldInterleavedOddFirst))
        pDesc->OutputFrameFreq.Numerator *= 2;

    return hr;


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]



See also

Media Foundation Structures