On Windows 8 load the mfcore.dll and invoke the MFStartup API in the

content/common/gpu/media/dxva_video_decode_accelerator.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/gpu/media/dxva_video_decode_accelerator.h"
 
 #if !defined(OS_WIN)
 #error This file should only be built on Windows.
 #endif   // !defined(OS_WIN)
 
 #include <ks.h>
 #include <codecapi.h>
 #include <mfapi.h>
 #include <mferror.h>
 #include <wmcodecdsp.h>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_handle.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
+#include "base/win/windows_version.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_surface_egl.h"
 #include "ui/gl/gl_switches.h"
 
 namespace content {
 
 // We only request 5 picture buffers from the client which are used to hold the
 // decoded samples. These buffers are then reused when the client tells us that
 // it is done with the buffer.
@@ skipping 352 matching lines @@
   for (int i = 0; i < arraysize(kDecodingDlls); ++i) {
     if (!::LoadLibrary(kDecodingDlls[i])) {
       DLOG(ERROR) << "Failed to load decoder dll: " << kDecodingDlls[i]
                   << ", Error: " << ::GetLastError();
       return;
     }
   }
 
   RETURN_ON_FAILURE(CreateD3DDevManager(),
                     "Failed to initialize D3D device and manager",);
+
+  if (base::win::GetVersion() == base::win::VERSION_WIN8) {
+    // On Windows 8+ mf.dll forwards to mfcore.dll. It does not exist in
+    // Windows 7. Loading mfcore.dll fails on Windows 8.1 in the
+    // sandbox

[scherkus (not reviewing), 2013/08/29 23:56:00]

end sentences with periods.

[ananta, 2013/08/30 02:21:15]

Done.

+    if (!LoadLibrary(L"mfcore.dll")) {
+      DLOG(ERROR) << "Failed to load mfcore.dll, Error: " << ::GetLastError();
+      return;
+    }
+    // MFStartup needs to be called once outside the sandbox. It fails on
+    // Windows 8.1 with E_NOTIMPL if it is called the first time in the
+    // sandbox.
+    RETURN_ON_HR_FAILURE(MFStartup(MF_VERSION, MFSTARTUP_FULL),
+                         "MFStartup failed.",);
+  }
+
   pre_sandbox_init_done_ = true;
 }
 
 // static
 bool DXVAVideoDecodeAccelerator::CreateD3DDevManager() {
   HRESULT hr = Direct3DCreate9Ex(D3D_SDK_VERSION, &d3d9_);
   RETURN_ON_HR_FAILURE(hr, "Direct3DCreate9Ex failed", false);
 
   D3DPRESENT_PARAMETERS present_params = {0};
   present_params.BackBufferWidth = 1;
@@ skipping 757 matching lines @@
 
   for (index = picture_buffers.begin();
        index != picture_buffers.end();
        ++index) {
     DVLOG(1) << "Dismissing picture id: " << index->second->id();
     client_->DismissPictureBuffer(index->second->id());
   }
 }
 
 }  // namespace content