Is result of IMF2DBuffer::ContiguousCopyTo always top-down?

The documentation is not really clear on wether the data written by the ContiguousCopyTo method of the IMF2DBuffer interface is always top-down or if it preserves/depends on pitch/stride of the source data.

I stumbled upon the MFCreateDXSurfaceBuffer function which increases my confusion:

fBottomUpWhenLinear [in]
If TRUE, the buffer's IMF2DBuffer::ContiguousCopyTo method copies the buffer into a bottom-up format. The bottom-up format is compatible with GDI for uncompressed RGB images. If this parameter is FALSE, the ContiguousCopyTo method copies the buffer into a top-down format, which is compatible with DirectX.

So how can I find out if the pitch/stride of the contiguous result data is positive or negative?