Microsoft published the following documents describing DirectX acceleration for Video a little while ago.
Now I am wondering whether this would lower the Hardware Requirements for HD video in Lync?
The Current Hardware Requirements for VGA & HD Quality video are the following: Video: Dual Core 1.9 GHz processor or the latest version for VGA; Quad Core 2.0 GHz or the latest version for high definition
More info on the Hardware Requirements here : http://technet.microsoft.com/en-us/library/gg412781
DirectX® Video Acceleration Specification for Windows Media Video® v8, v9 and vA Decoding (Including SMPTE 421M "VC-1")
http://www.microsoft.com/en-us/download/details.aspx?id=25228
Defines extensions to DirectX Video Acceleration (DXVA) to support decoding of Windows Media Video.
Note : VC-1 is actually the Video Codec used by RTVideo
DirectX Video Acceleration (DXVA) Specification for H.264/MPEG-4 Scalable Video Coding (SVC) Off-Host VLD Mode Decoding
http://www.microsoft.com/en-us/download/details.aspx?id=30154
This document is the specification for support of Scalable Video Coding (SVC) according to the H.264/MPEG-4 video coding standard within the Microsoft Windows DirectX Video Acceleration (DXVA) API/DDI context.
Note : H.264 SVC is the Video Codec used by Lync 2013