diff --git a/Player/I420Effect.cpp b/Player/I420Effect.cpp
index f21dff4..b27d99d 100644
--- a/Player/I420Effect.cpp
+++ b/Player/I420Effect.cpp
@@ -73,14 +73,14 @@ IFACEMETHODIMP I420Effect::Initialize(
     return S_OK;
 }
 
-IFACEMETHODIMP I420Effect::PrepareForRender(D2D1_CHANGE_TYPE changeType)
+IFACEMETHODIMP I420Effect::PrepareForRender(D2D1_CHANGE_TYPE /*changeType*/)
 {
     return S_OK;
 }
 
 // SetGraph is only called when the number of inputs changes. This never happens as we publish this effect
 // as a single input effect.
-IFACEMETHODIMP I420Effect::SetGraph(_In_ ID2D1TransformGraph* pGraph)
+IFACEMETHODIMP I420Effect::SetGraph(_In_ ID2D1TransformGraph* /*pGraph*/)
 {
     return E_NOTIMPL;
 }
@@ -108,7 +108,7 @@ IFACEMETHODIMP I420Effect::SetDrawInfo(_In_ ID2D1DrawInfo* pDrawInfo)
 // we want to request an expanded region to account for pixels that the ripple
 // may need outside of the bounds of the destination.
 IFACEMETHODIMP I420Effect::MapOutputRectToInputRects(
-    _In_ const D2D1_RECT_L* pOutputRect,
+    _In_ const D2D1_RECT_L* /*pOutputRect*/,
     _Out_writes_(inputRectCount) D2D1_RECT_L* pInputRects,
     UINT32 inputRectCount
     ) const
@@ -124,8 +124,8 @@ IFACEMETHODIMP I420Effect::MapOutputRectToInputRects(
 
 IFACEMETHODIMP I420Effect::MapInputRectsToOutputRect(
     _In_reads_(inputRectCount) CONST D2D1_RECT_L* pInputRects,
-    _In_reads_(inputRectCount) CONST D2D1_RECT_L* pInputOpaqueSubRects,
-    UINT32 inputRectCount,
+    _In_reads_(inputRectCount) CONST D2D1_RECT_L* /*pInputOpaqueSubRects*/,
+    UINT32 /*inputRectCount*/,
     _Out_ D2D1_RECT_L* pOutputRect,
     _Out_ D2D1_RECT_L* pOutputOpaqueSubRect
     )
@@ -149,8 +149,8 @@ IFACEMETHODIMP I420Effect::MapInputRectsToOutputRect(
 }
 
 IFACEMETHODIMP I420Effect::MapInvalidRect(
-    UINT32 inputIndex,
-    D2D1_RECT_L invalidInputRect,
+    UINT32 /*inputIndex*/,
+    D2D1_RECT_L /*invalidInputRect*/,
     _Out_ D2D1_RECT_L* pInvalidOutputRect
     ) const
 {
diff --git a/Player/Player.vcxproj b/Player/Player.vcxproj
index 884cd43..9300b06 100644
--- a/Player/Player.vcxproj
+++ b/Player/Player.vcxproj
@@ -52,7 +52,7 @@
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PrecompiledHeader>Use</PrecompiledHeader>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <PreprocessorDefinitions>WIN32;_WINDOWS;_HAS_AUTO_PTR_ETC=1;_HAS_FUNCTION_ASSIGN=1;_HAS_OLD_IOSTREAMS_MEMBERS=1;_DEBUG;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <SDLCheck>true</SDLCheck>
@@ -81,7 +81,7 @@
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
-      <WarningLevel>Level3</WarningLevel>
+      <WarningLevel>Level4</WarningLevel>
       <PrecompiledHeader>Use</PrecompiledHeader>
       <Optimization>MaxSpeed</Optimization>
       <FunctionLevelLinking>true</FunctionLevelLinking>
diff --git a/Player/PlayerDoc.cpp b/Player/PlayerDoc.cpp
index 75d7810..0804e40 100644
--- a/Player/PlayerDoc.cpp
+++ b/Player/PlayerDoc.cpp
@@ -73,7 +73,7 @@ BOOL CPlayerDoc::OnNewDocument()
         {
             m_frameDecoder->close();
             UpdateAllViews(nullptr, UPDATE_HINT_CLOSING, nullptr);
-            const std::string url(CT2A(dlg.m_URL, CP_UTF8));
+            const std::string url(dlg.m_URL.GetString(), dlg.m_URL.GetString() + dlg.m_URL.GetLength());
             if (m_frameDecoder->openUrl(url))
             {
                 m_frameDecoder->play();
diff --git a/Player/PlayerViewDxva2.cpp b/Player/PlayerViewDxva2.cpp
index b35ac4f..5c6e42b 100644
--- a/Player/PlayerViewDxva2.cpp
+++ b/Player/PlayerViewDxva2.cpp
@@ -807,7 +807,7 @@ bool CPlayerViewDxva2::ProcessVideo()
 }
 
 
-void CPlayerViewDxva2::OnDraw(CDC* pDC)
+void CPlayerViewDxva2::OnDraw(CDC* /*pDC*/)
 {
     //CDocument* pDoc = GetDocument();
     // TODO: add draw code here
@@ -1109,7 +1109,7 @@ void CPlayerViewDxva2::OnErase(CWnd* pInitiator, CDC* pDC, BOOL isFullScreen)
         VERIFY(targetRgn.CreateRectRgnIndirect(&targetRect));
         CRgn combined;
         VERIFY(combined.CreateRectRgnIndirect(&rect));
-        int result = combined.CombineRgn(&clientRgn, &targetRgn, RGN_DIFF);
+        VERIFY(combined.CombineRgn(&clientRgn, &targetRgn, RGN_DIFF) != ERROR);
 
         // Save old brush
         CGdiObject* pOldBrush = pDC->SelectStockObject(BLACK_BRUSH);
diff --git a/video/decoderinterface.h b/video/decoderinterface.h
index 55c7a82..dc3b9bc 100644
--- a/video/decoderinterface.h
+++ b/video/decoderinterface.h
@@ -37,11 +37,12 @@ struct FrameDecoderListener
 {
     virtual ~FrameDecoderListener() {}
 
-    virtual void changedFramePosition(long long start, long long frame, long long total) {}
+    virtual void changedFramePosition(
+        long long /*start*/, long long /*frame*/, long long /*total*/) {}
     virtual void decoderClosed() {}
     virtual void fileReleased() {}
     virtual void fileLoaded() {}
-    virtual void volumeChanged(double volume) {}
+    virtual void volumeChanged(double /*volume*/) {}
 
     virtual void onEndOfStream() {}