DXVA convertion

Hi,
I have a mpeg2 video stream (m2v file extension) and I want to convert it into DXVA standard format in order to feed the IDCT and MCP block.
I am totally new to DXVA.
- Where can I get access to DXVA? by just download DirectX SDK edition?
- Moreover, I wonder how to do the conversion from a bit stream to DXVA standard format, can anyone help me?

Thanks,
Brian