Don't show HDR option if we know it's unsupported

app/backend/systemproperties.cpp

@@ -64,6 +64,16 @@ SystemProperties::SystemProperties()
     hasDiscordIntegration = false;
 #endif
 
+    // TODO: Do something smarter than this. We should be able to query
+    // this from the decoder (or just try VIDEO_FORMAT_H265_MAIN10 and
+    // fail if we don't get a hardware accelerated decoder).
+#ifdef Q_OS_DARWIN
+    // HDR is supported by the VideoToolbox renderer
+    supportsHdr = true;
+#else
+    supportsHdr = false;
+#endif
+
     unmappedGamepads = SdlInputHandler::getUnmappedGamepads();
 
     // Populate data that requires talking to SDL. We do it all in one shot