--- a/dom/media/platforms/wmf/DXVA2Manager.cpp
+++ b/dom/media/platforms/wmf/DXVA2Manager.cpp
@@ -106,16 +106,17 @@ public:
                       const nsIntRect& aRegion,
                       Image** aOutImage) override;
 
   bool SupportsConfig(IMFMediaType* aType, float aFramerate) override;
 
   bool CreateDXVA2Decoder(const VideoInfo& aVideoInfo,
                           nsACString& aFailureReason) override;
 
+  uint32_t GetVendorId() const override { return mVendorId; }
 private:
   bool CanCreateDecoder(const DXVA2_VideoDesc& aDesc,
                         const float aFramerate) const;
 
   already_AddRefed<IDirectXVideoDecoder>
   CreateDecoder(const DXVA2_VideoDesc& aDesc) const;
 
   RefPtr<IDirect3D9Ex> mD3D9;
@@ -123,16 +124,17 @@ private:
   RefPtr<IDirect3DDeviceManager9> mDeviceManager;
   RefPtr<D3D9RecycleAllocator> mTextureClientAllocator;
   RefPtr<IDirectXVideoDecoderService> mDecoderService;
   RefPtr<IDirect3DSurface9> mSyncSurface;
   RefPtr<IDirectXVideoDecoder> mDecoder;
   GUID mDecoderGUID;
   UINT32 mResetToken = 0;
   bool mFirstFrame = true;
+  uint32_t mVendorId = 0;
 };
 
 void GetDXVA2ExtendedFormatFromMFMediaType(IMFMediaType *pType,
                                            DXVA2_ExtendedFormat *pFormat)
 {
   // Get the interlace mode.
   MFVideoInterlaceMode interlace = MFVideoInterlaceMode(MFGetAttributeUINT32(
     pType, MF_MT_INTERLACE_MODE, MFVideoInterlace_Unknown));
@@ -389,17 +391,18 @@ D3D9DXVA2Manager::Init(layers::KnowsComp
   D3DADAPTER_IDENTIFIER9 adapter;
   hr = d3d9Ex->GetAdapterIdentifier(D3DADAPTER_DEFAULT, 0, &adapter);
   if (!SUCCEEDED(hr)) {
     aFailureReason = nsPrintfCString(
       "IDirect3D9Ex::GetAdapterIdentifier failed with error %X", hr);
     return hr;
   }
 
-  if (adapter.VendorId == 0x1022 && !gfxPrefs::PDMWMFSkipBlacklist()) {
+  mVendorId = adapter.VendorId;
+  if (mVendorId == 0x1022 && !gfxPrefs::PDMWMFSkipBlacklist()) {
     for (const auto& model : sAMDPreUVD4) {
       if (adapter.DeviceId == model) {
         mIsAMDPreUVD4 = true;
         break;
       }
     }
   }
 
@@ -620,16 +623,17 @@ public:
 
   bool IsD3D11() override { return true; }
 
   bool SupportsConfig(IMFMediaType* aType, float aFramerate) override;
 
   bool CreateDXVA2Decoder(const VideoInfo& aVideoInfo,
                           nsACString& aFailureReason) override;
 
+  uint32_t GetVendorId() const override { return mVendorId; }
 private:
   HRESULT CreateFormatConverter();
 
   HRESULT CreateOutputSample(RefPtr<IMFSample>& aSample,
                              ID3D11Texture2D* aTexture);
 
   bool CanCreateDecoder(const D3D11_VIDEO_DECODER_DESC& aDesc,
                         const float aFramerate) const;
@@ -643,16 +647,17 @@ private:
   RefPtr<MFTDecoder> mTransform;
   RefPtr<D3D11RecycleAllocator> mTextureClientAllocator;
   RefPtr<ID3D11VideoDecoder> mDecoder;
   RefPtr<layers::SyncObject> mSyncObject;
   GUID mDecoderGUID;
   uint32_t mWidth = 0;
   uint32_t mHeight = 0;
   UINT mDeviceManagerToken = 0;
+  uint32_t mVendorId = 0;
 };
 
 bool
 D3D11DXVA2Manager::SupportsConfig(IMFMediaType* aType, float aFramerate)
 {
   MOZ_ASSERT(NS_IsMainThread());
   D3D11_VIDEO_DECODER_DESC desc;
   desc.Guid = mDecoderGUID;
@@ -847,17 +852,18 @@ D3D11DXVA2Manager::InitInternal(layers::
   DXGI_ADAPTER_DESC adapterDesc;
   hr = adapter->GetDesc(&adapterDesc);
   if (!SUCCEEDED(hr)) {
     aFailureReason =
       nsPrintfCString("IDXGIAdapter::GetDesc failed with code %X", hr);
     return hr;
   }
 
-  if (adapterDesc.VendorId == 0x1022 && !gfxPrefs::PDMWMFSkipBlacklist()) {
+  mVendorId = adapterDesc.VendorId;
+  if (mVendorId == 0x1022 && !gfxPrefs::PDMWMFSkipBlacklist()) {
     for (const auto& model : sAMDPreUVD4) {
       if (adapterDesc.DeviceId == model) {
         mIsAMDPreUVD4 = true;
         break;
       }
     }
   }
 

--- a/dom/media/platforms/wmf/DXVA2Manager.h
+++ b/dom/media/platforms/wmf/DXVA2Manager.h
@@ -65,16 +65,17 @@ public:
   virtual bool SupportsConfig(IMFMediaType* aType, float aFramerate) = 0;
 
   // When we want to decode with DXVA2 directly instead of using it by MFT, we
   // need to take responsibility for creating a decoder and handle the related
   // decoding operations by ourself.
   virtual bool CreateDXVA2Decoder(const VideoInfo& aVideoInfo,
                                   nsACString& aFailureReason) = 0;
 
+  virtual uint32_t GetVendorId() const = 0;
 protected:
   Mutex mLock;
   DXVA2Manager();
 
   bool IsUnsupportedResolution(const uint32_t& aWidth,
                                const uint32_t& aHeight,
                                const float& aFramerate) const;
 

--- a/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
+++ b/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
@@ -564,16 +564,21 @@ WMFVideoMFTManager::InitInternal()
   if (!mUseHwAccel) {
     // Use VP8/9 MFT only if HW acceleration is available
     if (mStreamType == VP9 || mStreamType == VP8) {
       return false;
     }
     Telemetry::Accumulate(Telemetry::MEDIA_DECODER_BACKEND_USED,
                           uint32_t(media::MediaDecoderBackend::WMFSoftware));
   }
+  // We only allow intel VP9 decoder at this stage.
+  if ((mStreamType == VP9 || mStreamType == VP8) &&
+      (mDXVA2Manager->GetVendorId() != 0x8086 && !gfxPrefs::PDMWMFForceVP9())) {
+    return false;
+  }
 
   mDecoder = decoder;
   hr = SetDecoderMediaTypes();
   NS_ENSURE_TRUE(SUCCEEDED(hr), false);
 
   RefPtr<IMFMediaType> outputType;
   hr = mDecoder->GetOutputMediaType(outputType);
   NS_ENSURE_TRUE(SUCCEEDED(hr), hr);

--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -620,16 +620,17 @@ private:
                                                                HardwareVideoDecodingForceEnabled, bool, false);
 #ifdef XP_WIN
   DECL_GFX_PREF(Live, "media.windows-media-foundation.allow-d3d11-dxva", PDMWMFAllowD3D11, bool, true);
   DECL_GFX_PREF(Live, "media.windows-media-foundation.max-dxva-videos", PDMWMFMaxDXVAVideos, uint32_t, 8);
   DECL_GFX_PREF(Live, "media.windows-media-foundation.use-nv12-format", PDMWMFUseNV12Format, bool, true);
   DECL_GFX_PREF(Once, "media.windows-media-foundation.use-sync-texture", PDMWMFUseSyncTexture, bool, true);
   DECL_GFX_PREF(Live, "media.wmf.low-latency.enabled", PDMWMFLowLatencyEnabled, bool, false);
   DECL_GFX_PREF(Live, "media.wmf.skip-blacklist", PDMWMFSkipBlacklist, bool, false);
+  DECL_GFX_PREF(Live, "media.wmf.vp9.force.enabled", PDMWMFForceVP9, bool, false);
 #endif
 
   // These affect how line scrolls from wheel events will be accelerated.
   DECL_GFX_PREF(Live, "mousewheel.acceleration.factor",        MouseWheelAccelerationFactor, int32_t, -1);
   DECL_GFX_PREF(Live, "mousewheel.acceleration.start",         MouseWheelAccelerationStart, int32_t, -1);
 
   // This affects whether events will be routed through APZ or not.
   DECL_GFX_PREF(Live, "mousewheel.system_scroll_override_on_root_content.enabled",

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -348,20 +348,21 @@ pref("media.mp4.enabled", true);
 // decoder works on all platforms.
 pref("media.use-blank-decoder", false);
 #ifdef MOZ_WMF
 pref("media.wmf.enabled", true);
 pref("media.wmf.decoder.thread-count", -1);
 pref("media.wmf.low-latency.enabled", false);
 pref("media.wmf.skip-blacklist", false);
 #ifdef NIGHTLY_BUILD
-pref("media.wmf.vp9.enabled", true);
+pref("media.wmf.vp9.force.enabled", true);
 #else
-pref("media.wmf.vp9.enabled", false);
+pref("media.wmf.vp9.force.enabled", false);
 #endif
+pref("media.wmf.vp9.enabled", true);
 pref("media.wmf.allow-unsupported-resolutions", false);
 pref("media.windows-media-foundation.allow-d3d11-dxva", true);
 pref("media.wmf.disable-d3d11-for-dlls", "igd11dxva64.dll: 20.19.15.4463, 20.19.15.4454, 20.19.15.4444, 20.19.15.4416, 20.19.15.4404, 20.19.15.4390, 20.19.15.4380, 20.19.15.4377, 20.19.15.4364, 20.19.15.4360, 20.19.15.4352, 20.19.15.4331, 20.19.15.4326, 20.19.15.4300; igd10iumd32.dll: 20.19.15.4444, 20.19.15.4424, 20.19.15.4409, 20.19.15.4390, 20.19.15.4380, 20.19.15.4360, 10.18.10.4358, 20.19.15.4331, 20.19.15.4312, 20.19.15.4300, 10.18.15.4281, 10.18.15.4279, 10.18.10.4276, 10.18.15.4268, 10.18.15.4256, 10.18.10.4252, 10.18.15.4248, 10.18.14.4112, 10.18.10.3958, 10.18.10.3496, 10.18.10.3431, 10.18.10.3412, 10.18.10.3355, 9.18.10.3234, 9.18.10.3071, 9.18.10.3055, 9.18.10.3006; igd10umd32.dll: 9.17.10.4229, 9.17.10.3040, 9.17.10.2857, 8.15.10.2274, 8.15.10.2272, 8.15.10.2246, 8.15.10.1840, 8.15.10.1808; igd10umd64.dll: 9.17.10.4229, 9.17.10.2857, 10.18.10.3496; isonyvideoprocessor.dll: 4.1.2247.8090, 4.1.2153.6200; tosqep.dll: 1.2.15.526, 1.1.12.201, 1.0.11.318, 1.0.11.215, 1.0.10.1224; tosqep64.dll: 1.1.12.201, 1.0.11.215; nvwgf2um.dll: 10.18.13.6510, 10.18.13.5891, 10.18.13.5887, 10.18.13.5582, 10.18.13.5382, 9.18.13.4195, 9.18.13.3165; atidxx32.dll: 21.19.151.3, 21.19.142.257, 21.19.137.514, 21.19.137.1, 21.19.134.1, 21.19.128.7, 21.19.128.4, 20.19.0.32837, 20.19.0.32832, 8.17.10.682, 8.17.10.671, 8.17.10.661, 8.17.10.648, 8.17.10.644, 8.17.10.625, 8.17.10.605, 8.17.10.581, 8.17.10.569, 8.17.10.560, 8.17.10.545, 8.17.10.539, 8.17.10.531, 8.17.10.525, 8.17.10.520, 8.17.10.519, 8.17.10.514, 8.17.10.511, 8.17.10.494, 8.17.10.489, 8.17.10.483, 8.17.10.453, 8.17.10.451, 8.17.10.441, 8.17.10.436, 8.17.10.432, 8.17.10.425, 8.17.10.418, 8.17.10.414, 8.17.10.401, 8.17.10.395, 8.17.10.385, 8.17.10.378, 8.17.10.362, 8.17.10.355, 8.17.10.342, 8.17.10.331, 8.17.10.318, 8.17.10.310, 8.17.10.286, 8.17.10.269, 8.17.10.261, 8.17.10.247, 8.17.10.240, 8.15.10.212; atidxx64.dll: 21.19.151.3, 21.19.142.257, 21.19.137.514, 21.19.137.1, 21.19.134.1, 21.19.128.7, 21.19.128.4, 20.19.0.32832, 8.17.10.682, 8.17.10.661, 8.17.10.644, 8.17.10.625; nvumdshim.dll: 10.18.13.6822");
 pref("media.wmf.disable-d3d9-for-dlls", "igdumd64.dll: 8.15.10.2189, 8.15.10.2119, 8.15.10.2104, 8.15.10.2102, 8.771.1.0; atiumd64.dll: 7.14.10.833, 7.14.10.867, 7.14.10.885, 7.14.10.903, 7.14.10.911, 8.14.10.768, 9.14.10.1001, 9.14.10.1017, 9.14.10.1080, 9.14.10.1128, 9.14.10.1162, 9.14.10.1171, 9.14.10.1183, 9.14.10.1197, 9.14.10.945, 9.14.10.972, 9.14.10.984, 9.14.10.996");
 #endif
 #if defined(MOZ_FFMPEG)
 #if defined(XP_MACOSX)
 pref("media.ffmpeg.enabled", false);