the Windows platform via DirectX Video Acceleration APIs. The native Windows WMV9/VC-1 decoder (wmvdecod.dll) only supports DXVA profiles A, B and C, while 3rd party VC-1 decoders such as CyberLink's support the full DXVA Profile D decode acceleration. There is no support for GPU-accelerated VC-1 decode on the MacOS platform. Raspberry Pi hardware prior to Raspberry Pi 4 supports VC-1 hardware-accelerated decoding, although it requires purchasing of a license key. Legal status Although heavily associated with Microsoft, there are 18 member companies within the VC-1 patent pool. The majority of patents are held by four companies: Microsoft (324 patents), Panasonic (122 patents), LG Electronics (96 patents), and Samsung Electronics (96 patents). As an SMPTE standard, VC-1 is open to implementation by anyone, although implementers may be required to pay licensing fees to the MPEG LA, the LLC licensing body or directly to its members, who claim to hold essential patents on the format (since it is a non-exclusive licensing body). Over 72.7% of the patents have expired as of January 29, 2022. Patent holders The following organizations hold one or more patents in the VC-1 patent pool, as listed by MPEG LA. See also AV1 Comparison of H.264 and VC-1 Video compression VC-2 (Dirac) References External links VC-1 reference software analysis at the MultimediaWiki – IETF RTP Payload Format for Video Codec 1 for the Raspberry Pi American inventions HD DVD High-definition television Japanese inventions Microsoft initiatives Open standards covered by patents Microsoft Silverlight SMPTE standards South Korean inventions Video codecs Video compression