HRESULT
GetDefaultStride(IMFMediaType *aType, uint32_t* aOutStride)
{
// Try to get the default stride from the media type.
HRESULT hr = aType->GetUINT32(MF_MT_DEFAULT_STRIDE, aOutStride);
if (SUCCEEDED(hr)) {
return S_OK;
}
// Stride attribute not set, calculate it.
GUID subtype = GUID_NULL;
uint32_t width = 0;
uint32_t height = 0;
hr = aType->GetGUID(MF_MT_SUBTYPE, &subtype);
ENSURE(SUCCEEDED(hr), hr);
hr = MFGetAttributeSize(aType, MF_MT_FRAME_SIZE, &width, &height);
ENSURE(SUCCEEDED(hr), hr);
hr = MFGetStrideForBitmapInfoHeader(subtype.Data1, width, (LONG*)(aOutStride));
ENSURE(SUCCEEDED(hr), hr);
return hr;
}
HRESULT GetDefaultStride(IMFMediaType *pType, LONG *plStride)
{
LONG lStride = 0;
// Try to get the default stride from the media type.
HRESULT hr = pType->GetUINT32(MF_MT_DEFAULT_STRIDE, (UINT32*)&lStride);
if (FAILED(hr))
{
// Attribute not set. Try to calculate the default stride.
GUID subtype = GUID_NULL;
UINT32 width = 0;
UINT32 height = 0;
// Get the subtype and the image size.
hr = pType->GetGUID(MF_MT_SUBTYPE, &subtype);
if (FAILED(hr))
{
goto done;
}
hr = MFGetAttributeSize(pType, MF_MT_FRAME_SIZE, &width, &height);
if (FAILED(hr))
{
goto done;
}
hr = MFGetStrideForBitmapInfoHeader(subtype.Data1, width, &lStride);
if (FAILED(hr))
{
goto done;
}
// Set the attribute for later reference.
(void)pType->SetUINT32(MF_MT_DEFAULT_STRIDE, UINT32(lStride));
}
if (SUCCEEDED(hr))
{
*plStride = lStride;
}
done:
return hr;
}
HRESULT CaptureClass::setVideoType(IMFMediaType *aType)
{
HRESULT hr = S_OK;
GUID subtype = { 0 };
// Find the video subtype.
hr = aType->GetGUID(MF_MT_SUBTYPE, &subtype);
DO_OR_DIE;
// Choose a conversion function.
// (This also validates the format type.)
hr = setConversionFunction(subtype);
DO_OR_DIE;
//
// Get some video attributes.
//
subtype = GUID_NULL;
UINT32 width = 0;
UINT32 height = 0;
// Get the subtype and the image size.
hr = aType->GetGUID(MF_MT_SUBTYPE, &subtype);
DO_OR_DIE;
hr = MFGetAttributeSize(aType, MF_MT_FRAME_SIZE, &width, &height);
DO_OR_DIE;
hr = MFGetStrideForBitmapInfoHeader(subtype.Data1, width, &mDefaultStride);
mCaptureBuffer = new unsigned int[width * height];
mCaptureBufferWidth = width;
mCaptureBufferHeight = height;
DO_OR_DIE;
return hr;
}
