Bug 1798052 - Disable D3D9DXVA2Manager on AMD pre UVD4 r=media-playback-reviewers,alwu

With AMD pre UVD4 GPU, hardware video decoding with D3D9DXVA2Manager outputs garbage for some videos.

D3D9DXVA2Manager is used only for fallback from D3D11DXVA2Manager. A new gpu driver normally does not use D3D9DXVA2Manager .

Differential Revision: https://phabricator.services.mozilla.com/D161976

dom/media/platforms/wmf/DXVA2Manager.cpp

@@ -482,6 +482,12 @@ D3D9DXVA2Manager::Init(layers::KnowsCompositor* aKnowsCompositor,
         break;
       }
     }
+    if (StaticPrefs::media_wmf_dxva_d3d9_amd_pre_uvd4_disabled() &&
+        mIsAMDPreUVD4) {
+      aFailureReason.AssignLiteral(
+          "D3D9DXVA2Manager is disabled on AMDPreUVD4");
+      return E_FAIL;
+    }
   }
 
   RefPtr<IDirect3DSurface9> syncSurf;

modules/libpref/init/StaticPrefList.yaml

@@ -9803,6 +9803,11 @@
     value: 8
     mirror: always
 
+-   name: media.wmf.dxva.d3d9.amd-pre-uvd4.disabled
+    type: RelaxedAtomicBool
+    value: true
+    mirror: always
+
 -   name: media.wmf.use-nv12-format
     type: RelaxedAtomicBool
     value: true