diff --git a/prompt2.txt b/prompt2.txt
index 6859f1e..acf9a8a 100644
--- a/prompt2.txt
+++ b/prompt2.txt
@@ -55,10 +55,10 @@ Vav2Player 에서 성능의 저하가 발생될 우려가 있는 부분을 진
 
 >>> WORK
 
-
 https://www.youtube.com/@%EC%84%9C%ED%98%84SeoHyeon1/shorts
 
 
+
 ● 주요 미완성 부분들:
 
   1. VP9 디코더 (미래 확장)
diff --git a/vav2/Vav2Player/Vav2Player/MainWindow.xaml b/vav2/Vav2Player/Vav2Player/MainWindow.xaml
index 4c4f714..b5b883b 100644
--- a/vav2/Vav2Player/Vav2Player/MainWindow.xaml
+++ b/vav2/Vav2Player/Vav2Player/MainWindow.xaml
@@ -34,44 +34,80 @@
         </Border>
 
         <!-- Player Controls -->
-        <StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Center" Margin="10">
-            <Button x:Name="OpenFileButton"
-                    Content="Open AV1 File"
-                    Width="120"
-                    Height="40"
-                    Margin="5"
-                    Click="OpenFileButton_Click"/>
+        <StackPanel Grid.Row="1" Orientation="Vertical" HorizontalAlignment="Center" Margin="10">
+            <!-- Main Control Buttons -->
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,0,0,10">
+                <Button x:Name="OpenFileButton"
+                        Content="Open AV1 File"
+                        Width="120"
+                        Height="40"
+                        Margin="5"
+                        Click="OpenFileButton_Click"/>
 
-            <Button x:Name="TestDecodeButton"
-                    Content="Test Decode"
-                    Width="100"
-                    Height="40"
-                    Margin="5"
-                    Click="TestDecodeButton_Click"/>
+                <Button x:Name="TestDecodeButton"
+                        Content="Test Decode"
+                        Width="100"
+                        Height="40"
+                        Margin="5"
+                        Click="TestDecodeButton_Click"/>
 
-            <Button x:Name="PlayButton"
-                    Content="Play"
-                    Width="80"
-                    Height="40"
-                    Margin="5"
-                    IsEnabled="False"
-                    Click="PlayButton_Click"/>
+                <Button x:Name="PlayButton"
+                        Content="Play"
+                        Width="80"
+                        Height="40"
+                        Margin="5"
+                        IsEnabled="False"
+                        Click="PlayButton_Click"/>
 
-            <Button x:Name="PauseButton"
-                    Content="Pause"
-                    Width="80"
-                    Height="40"
-                    Margin="5"
-                    IsEnabled="False"
-                    Click="PauseButton_Click"/>
+                <Button x:Name="PauseButton"
+                        Content="Pause"
+                        Width="80"
+                        Height="40"
+                        Margin="5"
+                        IsEnabled="False"
+                        Click="PauseButton_Click"/>
 
-            <Button x:Name="StopButton"
-                    Content="Stop"
-                    Width="80"
-                    Height="40"
-                    Margin="5"
-                    IsEnabled="False"
-                    Click="StopButton_Click"/>
+                <Button x:Name="StopButton"
+                        Content="Stop"
+                        Width="80"
+                        Height="40"
+                        Margin="5"
+                        IsEnabled="False"
+                        Click="StopButton_Click"/>
+            </StackPanel>
+
+            <!-- File Output Options -->
+            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
+                <CheckBox x:Name="EnableFileOutputCheckBox"
+                          Content="Save frames to files"
+                          IsChecked="False"
+                          VerticalAlignment="Center"
+                          Margin="10,0,20,0"
+                          Checked="EnableFileOutputCheckBox_Checked"
+                          Unchecked="EnableFileOutputCheckBox_Unchecked"/>
+
+                <ComboBox x:Name="OutputFormatComboBox"
+                          Width="120"
+                          Height="32"
+                          VerticalAlignment="Center"
+                          Margin="5,0,20,0"
+                          IsEnabled="False"
+                          SelectionChanged="OutputFormatComboBox_SelectionChanged">
+                    <ComboBoxItem Content="BMP Format" IsSelected="True"/>
+                    <ComboBoxItem Content="Raw YUV"/>
+                </ComboBox>
+
+                <TextBlock Text="Output folder:"
+                          VerticalAlignment="Center"
+                          Margin="0,0,5,0"/>
+                <TextBlock x:Name="OutputFolderText"
+                          Text="Not set"
+                          VerticalAlignment="Center"
+                          FontStyle="Italic"
+                          Foreground="Gray"
+                          MaxWidth="200"
+                          TextTrimming="CharacterEllipsis"/>
+            </StackPanel>
         </StackPanel>
 
         <!-- Status and Info Panel -->
diff --git a/vav2/Vav2Player/Vav2Player/MainWindow.xaml.cpp b/vav2/Vav2Player/Vav2Player/MainWindow.xaml.cpp
index 620b115..b81284d 100644
--- a/vav2/Vav2Player/Vav2Player/MainWindow.xaml.cpp
+++ b/vav2/Vav2Player/Vav2Player/MainWindow.xaml.cpp
@@ -31,6 +31,21 @@ public:
 
 namespace winrt::Vav2Player::implementation
 {
+    void MainWindow::InitializeUI()
+    {
+        try
+        {
+            // Initialize UI state
+            UpdateFileOutputControls();
+            UpdateStatus("Ready");
+
+            OutputDebugStringA("MainWindow UI initialized\n");
+        }
+        catch (const std::exception& e)
+        {
+            UpdateStatus("Error initializing UI: " + std::string(e.what()));
+        }
+    }
     void MainWindow::OpenFileButton_Click(Windows::Foundation::IInspectable const&, winrt::Microsoft::UI::Xaml::RoutedEventArgs const&)
     {
         try
@@ -88,15 +103,11 @@ namespace winrt::Vav2Player::implementation
 
             UpdateStatus("AV1 decoder initialized successfully!");
 
-            // Initialize FileOutput for BMP file saving
-            if (!m_fileOutput)
-            {
-                m_fileOutput = std::make_unique<FileOutput>();
-                if (!m_fileOutput->CreateOutputDirectory())
-                {
-                    UpdateStatus("Warning: Failed to create output directory");
-                }
-            }
+            // Initialize video rendering
+            InitializeVideoRenderer();
+
+            // FileOutput is now managed by the checkbox UI - don't create it here
+            // The checkbox event handlers will manage FileOutput creation/destruction
 
             // Reset file reading position
             m_fileReader->Reset();
@@ -193,12 +204,11 @@ namespace winrt::Vav2Player::implementation
             // Reset progress bar
             ProgressBar().Value(0);
 
-            // Clear video display
-            VideoImage().Source(nullptr);
-            m_renderBitmap = nullptr;
-            VideoDisplayArea().Visibility(winrt::Microsoft::UI::Xaml::Visibility::Visible);
+            // DO NOT destroy video renderer components - keep them for next playback
+            // The video renderer (m_renderBitmap, VideoImage) should remain intact
+            // Only reset playback state, not the display components
 
-            OutputDebugStringA("Playback stopped and reset\n");
+            OutputDebugStringA("Playback stopped and reset (renderer preserved)\n");
         }
         catch (...)
         {
@@ -290,23 +300,37 @@ namespace winrt::Vav2Player::implementation
                 // Successfully decoded frame
                 m_currentFrame++;
 
-                // Render frame to screen
+                // ALWAYS render frame to screen first (regardless of file output)
+                OutputDebugStringA(("Processing frame " + std::to_string(m_currentFrame) + " - Rendering to screen\n").c_str());
                 RenderFrameToScreen(frame);
+                OutputDebugStringA(("Frame " + std::to_string(m_currentFrame) + " rendered to screen successfully\n").c_str());
 
-                // Save frame as BMP file
-                if (m_fileOutput)
+                // Save frame to file if enabled (wrapped in try-catch to prevent UI blocking)
+                if (m_fileOutputEnabled && m_fileOutput)
                 {
-                    auto saveResult = m_fileOutput->SaveFrame(frame, m_currentFrame, 0.0);
-                    if (saveResult.success)
+                    try
                     {
-                        OutputDebugStringA(("Saved frame " + std::to_string(m_currentFrame) + " as BMP: " + saveResult.saved_path.string() + "\n").c_str());
+                        OutputDebugStringA(("Frame " + std::to_string(m_currentFrame) + " - Starting file save\n").c_str());
+                        auto saveResult = m_fileOutput->SaveFrame(frame, m_currentFrame, 0.0);
+                        if (saveResult.success)
+                        {
+                            OutputDebugStringA(("Saved frame " + std::to_string(m_currentFrame) + " to file: " + saveResult.saved_path.string() + "\n").c_str());
+                        }
+                        else
+                        {
+                            OutputDebugStringA(("Failed to save frame " + std::to_string(m_currentFrame) + " to file: " + saveResult.error_message + "\n").c_str());
+                        }
                     }
-                    else
+                    catch (const std::exception& e)
                     {
-                        OutputDebugStringA(("Failed to save frame " + std::to_string(m_currentFrame) + " as BMP: " + saveResult.error_message + "\n").c_str());
+                        OutputDebugStringA(("Exception during file save for frame " + std::to_string(m_currentFrame) + ": " + e.what() + "\n").c_str());
+                    }
+                    catch (...)
+                    {
+                        OutputDebugStringA(("Unknown exception during file save for frame " + std::to_string(m_currentFrame) + "\n").c_str());
                     }
                 }
-                else
+                else if (m_fileOutputEnabled)
                 {
                     OutputDebugStringA(("Frame " + std::to_string(m_currentFrame) + " not saved - FileOutput not initialized\n").c_str());
                 }
@@ -537,19 +561,8 @@ namespace winrt::Vav2Player::implementation
             // Initialize video rendering
             InitializeVideoRenderer();
 
-            // Initialize FileOutput for BMP file saving
-            if (!m_fileOutput)
-            {
-                m_fileOutput = std::make_unique<FileOutput>();
-                if (m_fileOutput->CreateOutputDirectory())
-                {
-                    OutputDebugStringA("FileOutput initialized - BMP saving enabled\n");
-                }
-                else
-                {
-                    OutputDebugStringA("Warning: Failed to create output directory for BMP files\n");
-                }
-            }
+            // FileOutput is now managed by the checkbox UI - don't create it here
+            // The checkbox event handlers will manage FileOutput creation/destruction
 
             // Reset playback position
             m_currentFrame = 0;
@@ -628,39 +641,86 @@ namespace winrt::Vav2Player::implementation
     {
         try
         {
+            OutputDebugStringA("InitializeVideoRenderer: Starting video renderer initialization\n");
+
+            if (!m_fileReader || !m_fileReader->IsFileOpen()) {
+                OutputDebugStringA("InitializeVideoRenderer: ERROR - No file reader or file not open\n");
+                UpdateStatus("Error: No file loaded for video renderer");
+                return;
+            }
+
             auto metadata = m_fileReader->GetVideoMetadata();
             int width = metadata.width;
             int height = metadata.height;
 
-            // Create WriteableBitmap with video dimensions
+            OutputDebugStringA(("InitializeVideoRenderer: Video dimensions: " + std::to_string(width) + "x" + std::to_string(height) + "\n").c_str());
+
+            if (width <= 0 || height <= 0) {
+                OutputDebugStringA("InitializeVideoRenderer: ERROR - Invalid video dimensions\n");
+                UpdateStatus("Error: Invalid video dimensions");
+                return;
+            }
+
+            // Always create a fresh bitmap - don't reuse existing one
+            OutputDebugStringA("InitializeVideoRenderer: Creating new WriteableBitmap\n");
             m_renderBitmap = winrt::Microsoft::UI::Xaml::Media::Imaging::WriteableBitmap(width, height);
 
+            if (!m_renderBitmap) {
+                OutputDebugStringA("InitializeVideoRenderer: ERROR - Failed to create WriteableBitmap\n");
+                UpdateStatus("Error: Failed to create video bitmap");
+                return;
+            }
+
             // Allocate buffer for BGRA conversion
             m_bgraBuffer.resize(width * height * 4);
+            OutputDebugStringA(("InitializeVideoRenderer: Allocated BGRA buffer: " + std::to_string(m_bgraBuffer.size()) + " bytes\n").c_str());
 
             // Set the bitmap as the source for the Image control
+            OutputDebugStringA("InitializeVideoRenderer: Setting bitmap as VideoImage source\n");
             VideoImage().Source(m_renderBitmap);
 
-            // Hide placeholder text
+            // Hide placeholder text and show video
+            OutputDebugStringA("InitializeVideoRenderer: Updating UI visibility\n");
             VideoDisplayArea().Visibility(winrt::Microsoft::UI::Xaml::Visibility::Collapsed);
 
+            OutputDebugStringA("InitializeVideoRenderer: Video renderer initialized successfully\n");
             UpdateStatus("Video renderer initialized");
         }
         catch (winrt::hresult_error const& ex)
         {
+            OutputDebugStringA(("InitializeVideoRenderer HRESULT error: " + winrt::to_string(ex.message()) + "\n").c_str());
             UpdateStatus("Error initializing video renderer: " + winrt::to_string(ex.message()));
         }
+        catch (const std::exception& ex)
+        {
+            OutputDebugStringA(("InitializeVideoRenderer std::exception: " + std::string(ex.what()) + "\n").c_str());
+            UpdateStatus("Error initializing video renderer: " + std::string(ex.what()));
+        }
+        catch (...)
+        {
+            OutputDebugStringA("InitializeVideoRenderer: Unknown exception occurred\n");
+            UpdateStatus("Error initializing video renderer: Unknown error");
+        }
     }
 
     void MainWindow::RenderFrameToScreen(const VideoFrame& frame)
     {
-        if (!frame.is_valid || !m_renderBitmap)
+        if (!frame.is_valid)
         {
+            OutputDebugStringA("RenderFrameToScreen: Frame is not valid\n");
+            return;
+        }
+
+        if (!m_renderBitmap)
+        {
+            OutputDebugStringA("RenderFrameToScreen: m_renderBitmap is null\n");
             return;
         }
 
         try
         {
+            OutputDebugStringA(("RenderFrameToScreen: Rendering frame " + std::to_string(frame.width) + "x" + std::to_string(frame.height) + "\n").c_str());
+
             // Convert YUV frame to our BGRA buffer
             ConvertYUVToBGRA(frame, m_bgraBuffer.data(), frame.width, frame.height);
 
@@ -670,16 +730,32 @@ namespace winrt::Vav2Player::implementation
             uint8_t* dest_pixels = nullptr;
             byteAccess->Buffer(&dest_pixels);
 
+            if (!dest_pixels)
+            {
+                OutputDebugStringA("RenderFrameToScreen: Failed to get pixel buffer\n");
+                return;
+            }
+
             // Copy our BGRA data into the WriteableBitmap
             memcpy(dest_pixels, m_bgraBuffer.data(), m_bgraBuffer.size());
 
             // Invalidate the bitmap to trigger a UI update
             m_renderBitmap.Invalidate();
+
+            OutputDebugStringA("RenderFrameToScreen: Frame rendered successfully\n");
         }
         catch (winrt::hresult_error const& ex)
         {
             OutputDebugStringA(("Error rendering frame: " + winrt::to_string(ex.message()) + "\n").c_str());
         }
+        catch (const std::exception& ex)
+        {
+            OutputDebugStringA(("Error rendering frame (std::exception): " + std::string(ex.what()) + "\n").c_str());
+        }
+        catch (...)
+        {
+            OutputDebugStringA("Error rendering frame: Unknown exception\n");
+        }
     }
 
     // This function converts an I420 YUV frame to a BGRA frame.
@@ -728,4 +804,142 @@ namespace winrt::Vav2Player::implementation
             }
         }
     }
+
+    // File Output Control Event Handlers
+    void MainWindow::EnableFileOutputCheckBox_Checked(winrt::Windows::Foundation::IInspectable const&, winrt::Microsoft::UI::Xaml::RoutedEventArgs const&)
+    {
+        m_fileOutputEnabled = true;
+        UpdateFileOutputControls();
+        InitializeFileOutput();
+        UpdateStatus("File output enabled");
+    }
+
+    void MainWindow::EnableFileOutputCheckBox_Unchecked(winrt::Windows::Foundation::IInspectable const&, winrt::Microsoft::UI::Xaml::RoutedEventArgs const&)
+    {
+        OutputDebugStringA("EnableFileOutputCheckBox_Unchecked: Starting\n");
+
+        m_fileOutputEnabled = false;
+
+        // Completely destroy FileOutput object when disabled
+        if (m_fileOutput) {
+            OutputDebugStringA("EnableFileOutputCheckBox_Unchecked: Destroying FileOutput object\n");
+            m_fileOutput.reset();
+        }
+
+        UpdateFileOutputControls();
+        UpdateStatus("File output disabled");
+
+        OutputDebugStringA("EnableFileOutputCheckBox_Unchecked: Completed\n");
+    }
+
+    void MainWindow::OutputFormatComboBox_SelectionChanged(winrt::Windows::Foundation::IInspectable const&, winrt::Microsoft::UI::Xaml::Controls::SelectionChangedEventArgs const&)
+    {
+        if (m_fileOutputEnabled && m_fileOutput) {
+            auto selectedIndex = OutputFormatComboBox().SelectedIndex();
+
+            FileOutput::OutputConfig config = m_fileOutput->GetConfig();
+
+            switch (selectedIndex) {
+                case 0: // BMP Format
+                    config.format = FileOutput::OutputFormat::BMP;
+                    UpdateStatus("Output format changed to BMP");
+                    break;
+                case 1: // Raw YUV
+                    config.format = FileOutput::OutputFormat::RawYUV;
+                    UpdateStatus("Output format changed to Raw YUV");
+                    break;
+                default:
+                    config.format = FileOutput::OutputFormat::BMP;
+                    break;
+            }
+
+            m_fileOutput->SetConfig(config);
+        }
+    }
+
+    // File Output Helper Methods
+    void MainWindow::UpdateFileOutputControls()
+    {
+        try {
+            // Enable/disable the format combo box based on checkbox state
+            OutputFormatComboBox().IsEnabled(m_fileOutputEnabled);
+
+            // Update output folder display
+            UpdateOutputFolderDisplay();
+        }
+        catch (const std::exception& e) {
+            UpdateStatus("Error updating file output controls: " + std::string(e.what()));
+        }
+    }
+
+    void MainWindow::InitializeFileOutput()
+    {
+        if (!m_fileOutputEnabled) {
+            return;
+        }
+
+        try {
+            OutputDebugStringA("InitializeFileOutput: Starting FileOutput initialization\n");
+
+            // Only create new FileOutput if it doesn't exist or needs reconfiguration
+            if (!m_fileOutput) {
+                // Create FileOutput with default configuration
+                FileOutput::OutputConfig config;
+                config.format = FileOutput::OutputFormat::BMP;
+                config.output_directory = "output";
+                config.filename_prefix = "frame";
+                config.create_subdirectories = true;
+                config.overwrite_existing = true;
+
+                OutputDebugStringA("InitializeFileOutput: Creating new FileOutput object\n");
+                m_fileOutput = std::make_unique<FileOutput>(config);
+
+                // Create output directory
+                if (!m_fileOutput->CreateOutputDirectory()) {
+                    OutputDebugStringA("InitializeFileOutput: Failed to create output directory\n");
+                    UpdateStatus("Warning: Failed to create output directory");
+                } else {
+                    OutputDebugStringA("InitializeFileOutput: Output directory created successfully\n");
+                }
+            }
+
+            // Update the combo box selection to match
+            OutputFormatComboBox().SelectedIndex(0); // BMP by default
+
+            UpdateOutputFolderDisplay();
+            UpdateStatus("File output initialized successfully");
+            OutputDebugStringA("InitializeFileOutput: FileOutput initialization completed successfully\n");
+        }
+        catch (const std::exception& e) {
+            OutputDebugStringA(("InitializeFileOutput error: " + std::string(e.what()) + "\n").c_str());
+            UpdateStatus("Error initializing file output: " + std::string(e.what()));
+
+            // Don't automatically turn off the checkbox - let user decide
+            // m_fileOutputEnabled = false;
+            // EnableFileOutputCheckBox().IsChecked(false);
+            // UpdateFileOutputControls();
+        }
+    }
+
+    void MainWindow::UpdateOutputFolderDisplay()
+    {
+        try {
+            if (m_fileOutput && m_fileOutputEnabled) {
+                auto config = m_fileOutput->GetConfig();
+                std::string displayPath = config.output_directory.string();
+
+                // Convert to wide string for display
+                std::wstring widePath(displayPath.begin(), displayPath.end());
+                OutputFolderText().Text(widePath);
+                OutputFolderText().Foreground(winrt::Microsoft::UI::Xaml::Media::SolidColorBrush(winrt::Microsoft::UI::Colors::Black()));
+            } else {
+                OutputFolderText().Text(L"Not set");
+                OutputFolderText().Foreground(winrt::Microsoft::UI::Xaml::Media::SolidColorBrush(winrt::Microsoft::UI::Colors::Gray()));
+            }
+        }
+        catch (const std::exception& e) {
+            OutputFolderText().Text(L"Error");
+            OutputFolderText().Foreground(winrt::Microsoft::UI::Xaml::Media::SolidColorBrush(winrt::Microsoft::UI::Colors::Red()));
+        }
+    }
 }
diff --git a/vav2/Vav2Player/Vav2Player/MainWindow.xaml.h b/vav2/Vav2Player/Vav2Player/MainWindow.xaml.h
index 1562765..2f6e3f6 100644
--- a/vav2/Vav2Player/Vav2Player/MainWindow.xaml.h
+++ b/vav2/Vav2Player/Vav2Player/MainWindow.xaml.h
@@ -16,6 +16,7 @@ namespace winrt::Vav2Player::implementation
         {
             // Initialize XAML components and event handlers
             InitializeComponent();
+            InitializeUI();
         }
 
         // Event handlers
@@ -25,6 +26,11 @@ namespace winrt::Vav2Player::implementation
         void PauseButton_Click(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
         void StopButton_Click(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
 
+        // File Output control event handlers
+        void EnableFileOutputCheckBox_Checked(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
+        void EnableFileOutputCheckBox_Unchecked(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::RoutedEventArgs const& e);
+        void OutputFormatComboBox_SelectionChanged(winrt::Windows::Foundation::IInspectable const& sender, winrt::Microsoft::UI::Xaml::Controls::SelectionChangedEventArgs const& e);
+
     private:
         // Video processing components
         std::unique_ptr<WebMFileReader> m_fileReader;
@@ -41,6 +47,7 @@ namespace winrt::Vav2Player::implementation
         // UI state
         bool m_isPlaying = false;
         bool m_isFileLoaded = false;
+        bool m_fileOutputEnabled = false;
 
         // Playback state
         uint64_t m_currentFrame = 0;
@@ -59,6 +66,12 @@ namespace winrt::Vav2Player::implementation
         void InitializePlayback();
         void StartPlaybackTimer();
         void StopPlaybackTimer();
+        void InitializeUI();
+
+        // File Output helper methods
+        void UpdateFileOutputControls();
+        void InitializeFileOutput();
+        void UpdateOutputFolderDisplay();
 
         // Video rendering methods
         void InitializeVideoRenderer();