Issue #1820 - Part 8: Check bit depth in PDM::Supports.

dom/media/platforms/ffmpeg/FFmpegDecoderModule.h

@@ -77,6 +77,21 @@ public:
     }
   }
 
+protected:
+  bool SupportsBitDepth(const uint8_t aBitDepth,
+                        DecoderDoctorDiagnostics* aDiagnostics) const override
+  {
+    // We don't support bitDepth > 8 when compositor backend is D3D11.
+    // But we don't have KnowsCompositor or any object
+    // that we can ask for the layersbackend type.
+    // We should remove this restriction until
+    // we solve the D3D11 compositor backend issue.
+#if defined(XP_LINUX) || defined(XP_MACOSX)
+    return true;
+#endif
+    return aBitDepth == 8;
+  }
+
 private:
   FFmpegLibWrapper* mLib;
 };