So, I tried to follow the steps described in the "How to run Media SDK samples on Skylake" post at https://software.intel.com/en-us/forums/intel-media-sdk/topic/593838 . The encoding steps worked for me, but the decoding steps do not. The post says to use the following command-line for decoding: sample_decode h265 -i <inputfile> -o <outputfile> -hw .
This definitely does not work. For the encoding command-line, it says to use -p 6fadc791a0c2eb479ab6dcd5ea9da347 to load the Skylake HEVC plug-in, but this isn't done for the decoding command-line. As a result, it uses the default for HEVC, the MFX_PLUGINID_HEVCD_SW plug-in, and this doesn't work, since the plug-in cannot be loaded. The call to MFXVideoUSER_Load() fails with MFX_ERR_NOT_FOUND. I don't know what is needed to install this plug-in, but it is definitely not provided by the latest Intel graphics driver package. Note that I'm using all the prerequisites as described in the post on a Windows 10 Skylake system. Plus, based on the name of the #define, it would seem that this GUID is associated with a SW HEVC plug-in, and I wouldn't want to use that anyway.
If instead, I use -p 6fadc791a0c2eb479ab6dcd5ea9da347 , it still doesn't work, unfortunately. It is able to load the plug-in just fine, but it fails when it calls m_pmfxDEC->DecodeHeader() with MFX_ERR_UNSUPPORTED. As an input file, I used the output file of HEVC encoding using sample_encode.exe, so I would expect that the input file is good. I also tried it with the test_stream.h265 file included with the samples in the _bin/content directory, and it failed the same way. I tried with -d3d and also with -d3d11, which didn't make any difference, and those wouldn't really make any difference for the DecodeHeader() call anyway.
Also, if anyone copies the command-line from the post exactly, it won't actually work. That's because in some cases (such as with -p), it uses a "long dash", and that results in a syntax error with the sample, which expects a '-' character as the option separator.
So, what is needed to get HEVC decoding working on Skylake?