Improve crop editor and copy publish output to dist

Add resize handles, zoom, view brightness, and a multi-frame still
strip. Keep the crop box on mouse-up, and copy AmiReel.exe to dist.

.gitignore

@@ -4,6 +4,7 @@
 [Dd]ebug/
 [Rr]elease/
 publish/
+dist/
 
 # IDE / tooling
 .vs/

AmiReel.Tests/Models/SourceCropSelectionTests.cs

@@ -57,6 +57,19 @@ public class SourceCropSelectionTests
         Assert.AreEqual(30, insets.Bottom);
     }
 
+    [TestMethod]
+    public void ToInsets_KeepsTheDraggedWidthAndHeight()
+    {
+        // Act
+        PixelInsets insets = SourceCropSelection.ToInsets(3840, 2160, 768, 432, 100, 50, 200, 120);
+
+        // Assert
+        Assert.AreEqual(500, insets.Left);
+        Assert.AreEqual(250, insets.Top);
+        Assert.AreEqual(1000, 3840 - insets.Left - insets.Right);
+        Assert.AreEqual(600, 2160 - insets.Top - insets.Bottom);
+    }
+
     [TestMethod]
     public void ToInsets_DraggedUpAndLeft_NormalizesTheRectangle()
     {
@@ -97,4 +110,106 @@ public class SourceCropSelectionTests
         Assert.AreEqual(0, x);
         Assert.AreEqual(60, y);
     }
+
+    [TestMethod]
+    public void HitTest_OnNorthWestHandle_ReturnsNorthWest()
+    {
+        // Act
+        CropHit hit = SourceCropSelection.HitTest(20, 30, 80, 40, 20, 30, 12);
+
+        // Assert
+        Assert.AreEqual(CropHit.NorthWest, hit);
+    }
+
+    [TestMethod]
+    public void HitTest_InsideRectangle_ReturnsMove()
+    {
+        // Act
+        CropHit hit = SourceCropSelection.HitTest(20, 30, 80, 40, 50, 50, 12);
+
+        // Assert
+        Assert.AreEqual(CropHit.Move, hit);
+    }
+
+    [TestMethod]
+    public void HitTest_OutsideRectangle_ReturnsNone()
+    {
+        // Act
+        CropHit hit = SourceCropSelection.HitTest(20, 30, 80, 40, 2, 2, 12);
+
+        // Assert
+        Assert.AreEqual(CropHit.None, hit);
+    }
+
+    [TestMethod]
+    public void AdjustRect_Move_KeepsSizeAndClamps()
+    {
+        // Act
+        (double x, double y, double width, double height) =
+            SourceCropSelection.AdjustRect(10, 10, 40, 20, CropHit.Move, 100, -4, 80, 60);
+
+        // Assert
+        Assert.AreEqual(40, x);
+        Assert.AreEqual(6, y);
+        Assert.AreEqual(40, width);
+        Assert.AreEqual(20, height);
+    }
+
+    [TestMethod]
+    public void AdjustRect_EastHandle_ChangesWidthOnly()
+    {
+        // Act
+        (double x, double y, double width, double height) =
+            SourceCropSelection.AdjustRect(10, 10, 40, 20, CropHit.East, 8, 5, 80, 60);
+
+        // Assert
+        Assert.AreEqual(10, x);
+        Assert.AreEqual(10, y);
+        Assert.AreEqual(48, width);
+        Assert.AreEqual(20, height);
+    }
+
+    [TestMethod]
+    public void AdjustRect_WestHandle_MovesLeftEdge()
+    {
+        // Act
+        (double x, _, double width, _) =
+            SourceCropSelection.AdjustRect(20, 10, 40, 20, CropHit.West, 6, 0, 80, 60);
+
+        // Assert
+        Assert.AreEqual(26, x);
+        Assert.AreEqual(34, width);
+    }
+
+    [TestMethod]
+    public void Nudge_MovesBoxWithoutChangingSize()
+    {
+        // Arrange
+        PixelInsets start = new(10, 20, 8, 12);
+
+        // Act
+        PixelInsets moved = SourceCropSelection.Nudge(start, 100, 80, 4, 0);
+
+        // Assert
+        Assert.AreEqual(14, moved.Left);
+        Assert.AreEqual(16, moved.Right);
+        Assert.AreEqual(8, moved.Top);
+        Assert.AreEqual(12, moved.Bottom);
+    }
+
+    [TestMethod]
+    public void NudgeEdge_GrowsRightSide()
+    {
+        // Arrange
+        PixelInsets start = new(10, 20, 8, 12);
+
+        // Act
+        PixelInsets grown = SourceCropSelection.NudgeEdge(start, 100, 80, 0, 0, -4, 0);
+
+        // Assert
+        Assert.AreEqual(10, grown.Left);
+        Assert.AreEqual(16, grown.Right);
+        Assert.AreEqual(8, grown.Top);
+        Assert.AreEqual(12, grown.Bottom);
+    }
 }

AmiReel.Tests/Services/ShortsPipelineTests.cs

@@ -483,6 +483,39 @@ public class ShortsPipelineTests
         CollectionAssert.Contains(args, "in.mp4");
     }
 
+    [TestMethod]
+    public void CropPreviewOffsets_SpreadsFramesAcrossDuration()
+    {
+        // Act
+        IReadOnlyList<double> offsets = ShortsPipeline.CropPreviewOffsets(30, 5);
+
+        // Assert
+        Assert.AreEqual(5, offsets.Count);
+        Assert.AreEqual(0, offsets[0]);
+        Assert.AreEqual(29.85, offsets[^1]);
+        Assert.AreEqual(14.925, offsets[2]);
+    }
+
+    [TestMethod]
+    public void CropPreviewOffsets_WithZeroDuration_ReturnsStartOnly()
+    {
+        // Act
+        IReadOnlyList<double> offsets = ShortsPipeline.CropPreviewOffsets(0);
+
+        // Assert
+        CollectionAssert.AreEqual(new[] { 0d }, offsets.ToArray());
+    }
+
+    [TestMethod]
+    public void FormatPreviewOffsetLabel_UnderOneHour_UsesMinutesAndSeconds()
+    {
+        // Act
+        string label = ShortsPipeline.FormatPreviewOffsetLabel(75);
+
+        // Assert
+        Assert.AreEqual("1:15", label);
+    }
+
     [TestMethod]
     public void BuildExtractFrameArguments_SeeksToStartAndWritesOnePng()
     {

Controls/SourceCropEditor.xaml

@@ -9,7 +9,7 @@
 
     <StackPanel Spacing="10" MinWidth="640">
         <TextBlock x:Name="StatusText"
-                   Text="Drag on the frame to keep that region. The rest is cropped away."
+                   Text="Drag a keep-region, then resize it with the handles. Zoom and brightness are for viewing only."
                    Style="{StaticResource MutedTextStyle}"
                    TextWrapping="WrapWholeWords" />
         <ProgressBar x:Name="LoadProgress"
@@ -17,32 +17,95 @@
                      Height="6"
                      Visibility="Collapsed"
                      AutomationProperties.Name="Loading source frame" />
+        <Grid ColumnSpacing="16">
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="*" />
+            </Grid.ColumnDefinitions>
+            <Slider x:Name="ZoomSlider"
+                    Grid.Column="0"
+                    Header="Zoom"
+                    Minimum="1"
+                    Maximum="4"
+                    StepFrequency="0.25"
+                    TickFrequency="0.5"
+                    SnapsTo="StepValues"
+                    Value="1"
+                    ValueChanged="ZoomSlider_ValueChanged"
+                    AutomationProperties.Name="View zoom"
+                    AutomationProperties.AutomationId="CropZoomSlider" />
+            <Slider x:Name="BrightnessSlider"
+                    Grid.Column="1"
+                    Header="View brightness"
+                    Minimum="-0.7"
+                    Maximum="0.7"
+                    StepFrequency="0.05"
+                    TickFrequency="0.35"
+                    SnapsTo="StepValues"
+                    Value="0"
+                    ValueChanged="BrightnessSlider_ValueChanged"
+                    AutomationProperties.Name="View brightness"
+                    AutomationProperties.AutomationId="CropBrightnessSlider" />
+        </Grid>
+        <ScrollViewer HorizontalScrollBarVisibility="Auto"
+                      VerticalScrollBarVisibility="Disabled"
+                      HorizontalScrollMode="Auto"
+                      VerticalScrollMode="Disabled"
+                      AutomationProperties.Name="Crop preview frames">
+            <StackPanel x:Name="FrameStrip" Orientation="Horizontal" Spacing="8" />
+        </ScrollViewer>
         <Border Background="{ThemeResource PageBrush}"
                 BorderBrush="{ThemeResource BorderBrush}"
                 BorderThickness="1"
                 CornerRadius="8">
-            <Grid x:Name="CropHost"
+            <ScrollViewer x:Name="CropScroller"
                           Height="420"
+                          ZoomMode="Disabled"
+                          HorizontalScrollBarVisibility="Auto"
+                          VerticalScrollBarVisibility="Auto"
+                          HorizontalScrollMode="Auto"
+                          VerticalScrollMode="Auto"
+                          SizeChanged="CropScroller_SizeChanged"
+                          PointerWheelChanged="CropScroller_PointerWheelChanged"
+                          AutomationProperties.Name="Source crop view">
+                <Grid x:Name="ImageSurface"
+                      HorizontalAlignment="Center"
+                      VerticalAlignment="Center"
                       Background="Transparent"
-                  PointerPressed="CropHost_PointerPressed"
-                  PointerMoved="CropHost_PointerMoved"
-                  PointerReleased="CropHost_PointerReleased"
-                  PointerCaptureLost="CropHost_PointerCaptureLost"
-                  SizeChanged="CropHost_SizeChanged"
+                      IsTabStop="True"
+                      UseSystemFocusVisuals="True"
+                      PointerPressed="ImageSurface_PointerPressed"
+                      PointerMoved="ImageSurface_PointerMoved"
+                      PointerReleased="ImageSurface_PointerReleased"
+                      PointerCaptureLost="ImageSurface_PointerCaptureLost"
+                      KeyDown="ImageSurface_KeyDown"
                       AutomationProperties.Name="Source crop frame"
                       AutomationProperties.AutomationId="SourceCropHost">
                     <Image x:Name="SourceImage"
-                       Stretch="Uniform"
+                           Stretch="Fill"
                            IsHitTestVisible="False"
                            AutomationProperties.Name="Source video frame" />
+                    <Rectangle x:Name="BrightnessOverlay"
+                               IsHitTestVisible="False"
+                               Fill="White"
+                               Opacity="0" />
                     <Canvas x:Name="OverlayCanvas" IsHitTestVisible="False">
                         <Rectangle x:Name="SelectionRect"
                                    Stroke="{ThemeResource AccentBrush}"
                                    StrokeThickness="2"
                                    Fill="#33007ACC"
                                    Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleNW" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleN" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleNE" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleE" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleSE" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleS" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleSW" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
+                        <Rectangle x:Name="HandleW" Width="10" Height="10" Fill="{ThemeResource AccentBrush}" Stroke="{ThemeResource PageBrush}" StrokeThickness="1" Visibility="Collapsed" />
                     </Canvas>
                 </Grid>
+            </ScrollViewer>
         </Border>
         <Grid ColumnSpacing="10">
             <Grid.ColumnDefinitions>

Controls/SourceCropEditor.xaml.cs

@@ -1,21 +1,43 @@
 using System.Runtime.InteropServices.WindowsRuntime;
 using AmiReel.Models;
 using AmiReel.Services;
+using Microsoft.UI;
 using Microsoft.UI.Input;
 using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Automation;
 using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Input;
+using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Media.Imaging;
 using Windows.Foundation;
+using Windows.System;
+using Windows.UI.Core;
 
 namespace AmiReel.Controls;
 
 public sealed partial class SourceCropEditor : UserControl
 {
+    private const double HandleHitSize = 12;
+    private const double HandleVisualSize = 10;
+    private const double MinZoom = 1;
+    private const double MaxZoom = 4;
+    private const double ZoomStep = 0.25;
+    private const int ThumbnailWidth = 128;
+
+    private readonly List<Button> _frameButtons = [];
+    private readonly List<string> _framePaths = [];
+    private readonly List<string> _frameLabels = [];
+    private readonly List<BitmapImage?> _fullFrames = [];
+    private int _selectedFrame;
+
     private int _pixelWidth;
     private int _pixelHeight;
+    private double _zoom = 1;
     private bool _isDragging;
+    private CropHit _dragHit = CropHit.None;
     private Point _dragStart;
+    private Rect _dragOriginRect;
     private PixelInsets _insets;
 
     public SourceCropEditor()
@@ -26,26 +48,34 @@ public sealed partial class SourceCropEditor : UserControl
     public PixelInsets Insets => _insets;
 
     public async Task LoadVideoFrameAsync(
-        string inputFile, string start, string ffmpegPath, string ffprobePath, CancellationToken token)
+        string inputFile, string start, double durationSeconds, string ffmpegPath, string ffprobePath, CancellationToken token)
     {
         LoadProgress.Visibility = Visibility.Visible;
-        StatusText.Text = "Loading a source frame...";
+        StatusText.Text = "Loading preview frames...";
         try
         {
-            string directory = Path.Combine(Path.GetTempPath(), "AmiReel", "crop-editor");
-            Directory.CreateDirectory(directory);
-            string framePath = Path.Combine(directory, "source-frame.png");
-            await new ShortsPipeline().ExtractSourceFrameAsync(
-                inputFile, start, ffmpegPath, ffprobePath, framePath, _ => { }, token);
+            IReadOnlyList<double> offsets = ShortsPipeline.CropPreviewOffsets(durationSeconds);
+            string directory = Path.Combine(Path.GetTempPath(), "AmiReel", "crop-editor", Guid.NewGuid().ToString("N"));
+            ShortsPipeline pipeline = new();
+            IReadOnlyList<string> paths = await pipeline.ExtractSourceFramesAsync(
+                inputFile, start, offsets, ffmpegPath, ffprobePath, directory, _ => { }, token);
 
-            await using FileStream stream = File.OpenRead(framePath);
-            BitmapImage bitmap = new();
-            await bitmap.SetSourceAsync(stream.AsRandomAccessStream());
-            SourceImage.Source = bitmap;
-            _pixelWidth = bitmap.PixelWidth;
-            _pixelHeight = bitmap.PixelHeight;
-            StatusText.Text = $"{_pixelWidth} × {_pixelHeight} · drag on the frame to choose the kept region.";
-            RefreshSelectionVisual();
+            _framePaths.Clear();
+            _frameLabels.Clear();
+            _fullFrames.Clear();
+            _frameButtons.Clear();
+            FrameStrip.Children.Clear();
+
+            for (int index = 0; index < paths.Count; index++)
+            {
+                _framePaths.Add(paths[index]);
+                _frameLabels.Add(ShortsPipeline.FormatPreviewOffsetLabel(offsets[index]));
+                _fullFrames.Add(null);
+                FrameStrip.Children.Add(CreateFrameButton(index, paths[index], _frameLabels[index]));
+            }
+
+            await ShowFrameAsync(0);
+            StatusText.Text = $"{_pixelWidth} × {_pixelHeight} · pick a still, then drag a region and fine-tune the handles.";
         }
         finally
         {
@@ -60,112 +90,394 @@ public sealed partial class SourceCropEditor : UserControl
         UpdateInsetsText();
     }
 
-    private void CropHost_PointerPressed(object sender, PointerRoutedEventArgs e)
+    private Button CreateFrameButton(int index, string path, string label)
     {
-        if (_pixelWidth <= 0 || !TryMapToDisplay(e, out double x, out double y, out _, out _))
+        Image thumb = new()
+        {
+            Width = 112,
+            Height = 63,
+            Stretch = Stretch.Uniform,
+            IsHitTestVisible = false,
+        };
+        _ = LoadThumbnailAsync(thumb, path);
+
+        TextBlock caption = new()
+        {
+            Text = label,
+            FontSize = 11,
+            HorizontalAlignment = HorizontalAlignment.Center,
+            Style = (Style)Application.Current.Resources["MutedTextStyle"],
+        };
+
+        StackPanel content = new() { Spacing = 4 };
+        content.Children.Add(thumb);
+        content.Children.Add(caption);
+
+        Button button = new()
+        {
+            Content = content,
+            Padding = new Thickness(6),
+            Tag = index,
+            BorderThickness = new Thickness(2),
+        };
+        AutomationProperties.SetName(button, $"Preview at {label}");
+        AutomationProperties.SetAutomationId(button, $"CropPreviewFrame{index}");
+        button.Click += FrameButton_Click;
+        _frameButtons.Add(button);
+        return button;
+    }
+
+    private async void FrameButton_Click(object sender, RoutedEventArgs e)
+    {
+        if (sender is not Button button || button.Tag is not int index)
             return;
 
+        try
+        {
+            await ShowFrameAsync(index);
+        }
+        catch (Exception exception)
+        {
+            StatusText.Text = exception.Message;
+        }
+    }
+
+    private async Task ShowFrameAsync(int index)
+    {
+        if (index < 0 || index >= _framePaths.Count)
+            return;
+
+        _selectedFrame = index;
+        UpdateFrameButtonStyles();
+
+        if (_fullFrames[index] is null)
+            _fullFrames[index] = await LoadBitmapAsync(_framePaths[index], decodePixelWidth: 0);
+
+        BitmapImage bitmap = _fullFrames[index]!;
+        SourceImage.Source = bitmap;
+        if (bitmap.PixelWidth > 0 && bitmap.PixelHeight > 0)
+        {
+            _pixelWidth = bitmap.PixelWidth;
+            _pixelHeight = bitmap.PixelHeight;
+        }
+
+        ApplyViewTransform();
+        RefreshSelectionVisual();
+        UpdateInsetsText();
+        StatusText.Text = $"{_pixelWidth} × {_pixelHeight} · {_frameLabels[index]}  ({index + 1} of {_framePaths.Count})";
+    }
+
+    private void UpdateFrameButtonStyles()
+    {
+        Brush accent = (Brush)Application.Current.Resources["AccentBrush"];
+        Brush border = (Brush)Application.Current.Resources["BorderBrush"];
+        for (int index = 0; index < _frameButtons.Count; index++)
+            _frameButtons[index].BorderBrush = index == _selectedFrame ? accent : border;
+    }
+
+    private static async Task LoadThumbnailAsync(Image target, string path)
+    {
+        target.Source = await LoadBitmapAsync(path, ThumbnailWidth);
+    }
+
+    private static async Task<BitmapImage> LoadBitmapAsync(string path, int decodePixelWidth)
+    {
+        await using FileStream stream = File.OpenRead(path);
+        BitmapImage bitmap = new();
+        if (decodePixelWidth > 0)
+            bitmap.DecodePixelWidth = decodePixelWidth;
+        await bitmap.SetSourceAsync(stream.AsRandomAccessStream());
+        return bitmap;
+    }
+
+    private void ImageSurface_PointerPressed(object sender, PointerRoutedEventArgs e)
+    {
+        if (_pixelWidth <= 0 || !TryMapToDisplay(e, out double x, out double y, out double displayWidth, out double displayHeight))
+            return;
+
+        ImageSurface.Focus(FocusState.Pointer);
+        (double rectX, double rectY, double rectW, double rectH) = CurrentDisplayRect(displayWidth, displayHeight);
+        CropHit hit = _insets.IsEmpty
+            ? CropHit.None
+            : SourceCropSelection.HitTest(rectX, rectY, rectW, rectH, x, y, HandleHitSize);
+
         _isDragging = true;
+        _dragHit = hit;
         _dragStart = new Point(x, y);
-        CropHost.CapturePointer(e.Pointer);
-        UpdateDraftSelection(x, y);
+        _dragOriginRect = new Rect(rectX, rectY, rectW, rectH);
+        ImageSurface.CapturePointer(e.Pointer);
         e.Handled = true;
     }
 
-    private void CropHost_PointerMoved(object sender, PointerRoutedEventArgs e)
+    private void ImageSurface_PointerMoved(object sender, PointerRoutedEventArgs e)
     {
         if (!_isDragging)
+        {
+            UpdateHoverCursor(e);
             return;
-        if (!TryMapToDisplay(e, out double x, out double y, out _, out _))
+        }
+
+        if (!TryMapToDisplay(e, out double x, out double y, out double displayWidth, out double displayHeight))
             return;
 
+        if (_dragHit == CropHit.None)
             UpdateDraftSelection(x, y);
+        else
+            UpdateAdjustedSelection(x, y, displayWidth, displayHeight);
+
         e.Handled = true;
     }
 
-    private void CropHost_PointerReleased(object sender, PointerRoutedEventArgs e)
+    private void ImageSurface_PointerReleased(object sender, PointerRoutedEventArgs e)
     {
         if (!_isDragging)
             return;
 
-        _isDragging = false;
-        CropHost.ReleasePointerCapture(e.Pointer);
-        if (TryMapToDisplay(e, out double x, out double y, out double displayWidth, out double displayHeight))
-            CommitSelection(x, y, displayWidth, displayHeight);
+        EndDrag();
+        ImageSurface.ReleasePointerCapture(e.Pointer);
         e.Handled = true;
     }
 
-    private void CropHost_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
+    private void ImageSurface_PointerCaptureLost(object sender, PointerRoutedEventArgs e)
     {
-        _isDragging = false;
+        if (_isDragging)
+            EndDrag();
     }
 
-    private void CropHost_SizeChanged(object sender, SizeChangedEventArgs e) => RefreshSelectionVisual();
+    private void EndDrag()
+    {
+        _isDragging = false;
+        _dragHit = CropHit.None;
+        RefreshSelectionVisual();
+        UpdateInsetsText();
+    }
+
+    private void ImageSurface_KeyDown(object sender, KeyRoutedEventArgs e)
+    {
+        if (_pixelWidth <= 0)
+            return;
+
+        bool shift = InputKeyboardSource.GetKeyStateForCurrentThread(VirtualKey.Shift).HasFlag(CoreVirtualKeyStates.Down);
+        int step = 2;
+        PixelInsets next = _insets;
+        switch (e.Key)
+        {
+            case VirtualKey.Left:
+                next = shift
+                    ? SourceCropSelection.NudgeEdge(_insets, _pixelWidth, _pixelHeight, -step, 0, 0, 0)
+                    : SourceCropSelection.Nudge(_insets, _pixelWidth, _pixelHeight, -step, 0);
+                break;
+            case VirtualKey.Right:
+                next = shift
+                    ? SourceCropSelection.NudgeEdge(_insets, _pixelWidth, _pixelHeight, 0, 0, -step, 0)
+                    : SourceCropSelection.Nudge(_insets, _pixelWidth, _pixelHeight, step, 0);
+                break;
+            case VirtualKey.Up:
+                next = shift
+                    ? SourceCropSelection.NudgeEdge(_insets, _pixelWidth, _pixelHeight, 0, -step, 0, 0)
+                    : SourceCropSelection.Nudge(_insets, _pixelWidth, _pixelHeight, 0, -step);
+                break;
+            case VirtualKey.Down:
+                next = shift
+                    ? SourceCropSelection.NudgeEdge(_insets, _pixelWidth, _pixelHeight, 0, 0, 0, -step)
+                    : SourceCropSelection.Nudge(_insets, _pixelWidth, _pixelHeight, 0, step);
+                break;
+            default:
+                return;
+        }
+
+        if (_insets.IsEmpty)
+            return;
+
+        SetInsets(next);
+        e.Handled = true;
+    }
+
+    private void CropScroller_SizeChanged(object sender, SizeChangedEventArgs e) => ApplyViewTransform();
+
+    private void CropScroller_PointerWheelChanged(object sender, PointerRoutedEventArgs e)
+    {
+        if (!e.KeyModifiers.HasFlag(VirtualKeyModifiers.Control))
+            return;
+
+        double delta = e.GetCurrentPoint(CropScroller).Properties.MouseWheelDelta > 0 ? ZoomStep : -ZoomStep;
+        SetZoom(_zoom + delta);
+        e.Handled = true;
+    }
+
+    private void ZoomSlider_ValueChanged(object sender, RangeBaseValueChangedEventArgs e)
+    {
+        if (!IsLoaded)
+            return;
+        SetZoom(e.NewValue);
+    }
+
+    private void BrightnessSlider_ValueChanged(object sender, RangeBaseValueChangedEventArgs e)
+    {
+        if (!IsLoaded)
+            return;
+        ApplyBrightness(e.NewValue);
+    }
 
     private void ClearCrop_Click(object sender, RoutedEventArgs e) => SetInsets(default);
 
+    private void SetZoom(double zoom)
+    {
+        _zoom = Math.Clamp(Math.Round(zoom / ZoomStep) * ZoomStep, MinZoom, MaxZoom);
+        if (Math.Abs(ZoomSlider.Value - _zoom) > 0.001)
+            ZoomSlider.Value = _zoom;
+        ZoomSlider.Header = $"Zoom  {_zoom * 100:0}%";
+        ApplyViewTransform();
+    }
+
+    private void ApplyBrightness(double value)
+    {
+        double amount = Math.Clamp(value, -0.7, 0.7);
+        BrightnessOverlay.Fill = new SolidColorBrush(amount >= 0 ? Colors.White : Colors.Black);
+        BrightnessOverlay.Opacity = Math.Abs(amount);
+        BrightnessSlider.Header = amount == 0
+            ? "View brightness"
+            : $"View brightness  {(amount > 0 ? "+" : "")}{amount:0.00}";
+    }
+
+    private void ApplyViewTransform()
+    {
+        if (_pixelWidth <= 0)
+            return;
+
+        double viewportWidth = CropScroller.ActualWidth > 0 ? CropScroller.ActualWidth : 800;
+        double viewportHeight = CropScroller.ActualHeight > 0 ? CropScroller.ActualHeight : 420;
+        (_, _, double displayWidth, double displayHeight) =
+            SourceCropSelection.FitUniform(viewportWidth, viewportHeight, _pixelWidth, _pixelHeight);
+        ImageSurface.Width = Math.Max(1, displayWidth * _zoom);
+        ImageSurface.Height = Math.Max(1, displayHeight * _zoom);
+        RefreshSelectionVisual();
+    }
+
     private bool TryMapToDisplay(
         PointerRoutedEventArgs e, out double x, out double y, out double displayWidth, out double displayHeight)
     {
-        (double offsetX, double offsetY, displayWidth, displayHeight) = CurrentFit();
+        displayWidth = ImageSurface.Width;
+        displayHeight = ImageSurface.Height;
         x = 0;
         y = 0;
         if (displayWidth <= 0 || displayHeight <= 0)
             return false;
 
-        PointerPoint point = e.GetCurrentPoint(CropHost);
-        (x, y) = SourceCropSelection.ClampToDisplay(
-            point.Position.X - offsetX, point.Position.Y - offsetY, displayWidth, displayHeight);
+        PointerPoint point = e.GetCurrentPoint(ImageSurface);
+        (x, y) = SourceCropSelection.ClampToDisplay(point.Position.X, point.Position.Y, displayWidth, displayHeight);
         return true;
     }
 
     private void UpdateDraftSelection(double x, double y)
     {
-        (double offsetX, double offsetY, double displayWidth, double displayHeight) = CurrentFit();
+        double displayWidth = ImageSurface.Width;
+        double displayHeight = ImageSurface.Height;
         if (displayWidth <= 0)
             return;
 
+        double left = Math.Min(_dragStart.X, x);
+        double top = Math.Min(_dragStart.Y, y);
+        double width = Math.Abs(x - _dragStart.X);
+        double height = Math.Abs(y - _dragStart.Y);
+        ShowDisplayRect(left, top, width, height);
         _insets = SourceCropSelection.ToInsets(
-            _pixelWidth, _pixelHeight, displayWidth, displayHeight,
-            _dragStart.X, _dragStart.Y, x - _dragStart.X, y - _dragStart.Y);
-        PlaceSelectionRect(offsetX, offsetY, displayWidth, displayHeight);
+            _pixelWidth, _pixelHeight, displayWidth, displayHeight, left, top, width, height);
         UpdateInsetsText();
     }
 
-    private void CommitSelection(double x, double y, double displayWidth, double displayHeight)
+    private void UpdateAdjustedSelection(double x, double y, double displayWidth, double displayHeight)
     {
-        _insets = SourceCropSelection.ToInsets(
-            _pixelWidth, _pixelHeight, displayWidth, displayHeight,
-            _dragStart.X, _dragStart.Y, x - _dragStart.X, y - _dragStart.Y);
-        RefreshSelectionVisual();
+        (double nextX, double nextY, double nextW, double nextH) = SourceCropSelection.AdjustRect(
+            _dragOriginRect.X,
+            _dragOriginRect.Y,
+            _dragOriginRect.Width,
+            _dragOriginRect.Height,
+            _dragHit,
+            x - _dragStart.X,
+            y - _dragStart.Y,
+            displayWidth,
+            displayHeight);
+        ShowDisplayRect(nextX, nextY, nextW, nextH);
+        _insets = SourceCropSelection.ToInsets(_pixelWidth, _pixelHeight, displayWidth, displayHeight, nextX, nextY, nextW, nextH);
         UpdateInsetsText();
     }
 
     private void RefreshSelectionVisual()
     {
-        (double offsetX, double offsetY, double displayWidth, double displayHeight) = CurrentFit();
-        if (displayWidth <= 0 || _pixelWidth <= 0)
+        if (ImageSurface.Width <= 0 || _pixelWidth <= 0 || _insets.IsEmpty)
         {
-            SelectionRect.Visibility = Visibility.Collapsed;
+            SetHandlesVisible(false);
             return;
         }
 
-        PlaceSelectionRect(offsetX, offsetY, displayWidth, displayHeight);
+        (double x, double y, double width, double height) = CurrentDisplayRect(ImageSurface.Width, ImageSurface.Height);
+        ShowDisplayRect(x, y, width, height);
     }
 
-    private void PlaceSelectionRect(double offsetX, double offsetY, double displayWidth, double displayHeight)
+    private void ShowDisplayRect(double x, double y, double width, double height)
     {
-        (double x, double y, double width, double height) = SourceCropSelection.ToDisplayRect(
-            _pixelWidth, _pixelHeight, displayWidth, displayHeight, _insets);
-        Canvas.SetLeft(SelectionRect, offsetX + x);
-        Canvas.SetTop(SelectionRect, offsetY + y);
-        SelectionRect.Width = width;
-        SelectionRect.Height = height;
-        SelectionRect.Visibility = _insets.IsEmpty ? Visibility.Collapsed : Visibility.Visible;
+        Canvas.SetLeft(SelectionRect, x);
+        Canvas.SetTop(SelectionRect, y);
+        SelectionRect.Width = Math.Max(1, width);
+        SelectionRect.Height = Math.Max(1, height);
+        SelectionRect.Visibility = Visibility.Visible;
+        PlaceHandle(HandleNW, x, y);
+        PlaceHandle(HandleN, x + (width / 2), y);
+        PlaceHandle(HandleNE, x + width, y);
+        PlaceHandle(HandleE, x + width, y + (height / 2));
+        PlaceHandle(HandleSE, x + width, y + height);
+        PlaceHandle(HandleS, x + (width / 2), y + height);
+        PlaceHandle(HandleSW, x, y + height);
+        PlaceHandle(HandleW, x, y + (height / 2));
+        SetHandlesVisible(true);
     }
 
-    private (double OffsetX, double OffsetY, double DisplayWidth, double DisplayHeight) CurrentFit() =>
-        SourceCropSelection.FitUniform(CropHost.ActualWidth, CropHost.ActualHeight, _pixelWidth, _pixelHeight);
+    private (double X, double Y, double Width, double Height) CurrentDisplayRect(double displayWidth, double displayHeight) =>
+        SourceCropSelection.ToDisplayRect(_pixelWidth, _pixelHeight, displayWidth, displayHeight, _insets);
+
+    private void PlaceHandle(Microsoft.UI.Xaml.Shapes.Rectangle handle, double centerX, double centerY)
+    {
+        Canvas.SetLeft(handle, centerX - (HandleVisualSize / 2));
+        Canvas.SetTop(handle, centerY - (HandleVisualSize / 2));
+    }
+
+    private void SetHandlesVisible(bool visible)
+    {
+        Visibility visibility = visible ? Visibility.Visible : Visibility.Collapsed;
+        SelectionRect.Visibility = visibility;
+        HandleNW.Visibility = visibility;
+        HandleN.Visibility = visibility;
+        HandleNE.Visibility = visibility;
+        HandleE.Visibility = visibility;
+        HandleSE.Visibility = visibility;
+        HandleS.Visibility = visibility;
+        HandleSW.Visibility = visibility;
+        HandleW.Visibility = visibility;
+    }
+
+    private void UpdateHoverCursor(PointerRoutedEventArgs e)
+    {
+        if (_pixelWidth <= 0 || _insets.IsEmpty || !TryMapToDisplay(e, out double x, out double y, out double displayWidth, out double displayHeight))
+        {
+            ProtectedCursor = InputSystemCursor.Create(InputSystemCursorShape.Cross);
+            return;
+        }
+
+        (double rectX, double rectY, double rectW, double rectH) = CurrentDisplayRect(displayWidth, displayHeight);
+        CropHit hit = SourceCropSelection.HitTest(rectX, rectY, rectW, rectH, x, y, HandleHitSize);
+        ProtectedCursor = InputSystemCursor.Create(CursorFor(hit));
+    }
+
+    private static InputSystemCursorShape CursorFor(CropHit hit) => hit switch
+    {
+        CropHit.Move => InputSystemCursorShape.SizeAll,
+        CropHit.North or CropHit.South => InputSystemCursorShape.SizeNorthSouth,
+        CropHit.East or CropHit.West => InputSystemCursorShape.SizeWestEast,
+        CropHit.NorthWest or CropHit.SouthEast => InputSystemCursorShape.SizeNorthwestSoutheast,
+        CropHit.NorthEast or CropHit.SouthWest => InputSystemCursorShape.SizeNortheastSouthwest,
+        _ => InputSystemCursorShape.Cross,
+    };
 
     private void UpdateInsetsText() =>
         InsetsText.Text = _pixelWidth <= 0

MainPage.xaml.cs

@@ -612,9 +612,13 @@ public sealed partial class MainPage : Page
         {
             CropEditorDialog.XamlRoot = XamlRoot;
             CropEditorDialog.RequestedTheme = ActualTheme;
+            double duration = 30;
+            try { duration = ParsePositiveDuration(); } catch (ArgumentException) { }
+
             await ShortCropEditor.LoadVideoFrameAsync(
                 input,
                 string.IsNullOrWhiteSpace(ShortStartBox.Text) ? "00:00:00" : ShortStartBox.Text.Trim(),
+                duration,
                 FfmpegPathBox.Text.Trim(),
                 FfprobePathBox.Text.Trim(),
                 CancellationToken.None);

Models/SourceCropSelection.cs

@@ -6,6 +6,21 @@ public readonly record struct PixelInsets(int Left, int Right, int Top, int Bott
     public bool IsEmpty => Left == 0 && Right == 0 && Top == 0 && Bottom == 0;
 }
 
+/// <summary>Which part of an existing crop rectangle a pointer is on.</summary>
+public enum CropHit
+{
+    None,
+    Move,
+    North,
+    South,
+    East,
+    West,
+    NorthWest,
+    NorthEast,
+    SouthWest,
+    SouthEast,
+}
+
 /// <summary>Maps a dragged display rectangle onto source-pixel crop insets.</summary>
 public static class SourceCropSelection
 {
@@ -58,15 +73,14 @@ public static class SourceCropSelection
         double scaleY = pixelHeight / displayHeight;
         int left = ToEvenPixel(x * scaleX, pixelWidth - MinimumSize);
         int top = ToEvenPixel(y * scaleY, pixelHeight - MinimumSize);
-        int right = ToEvenPixel((displayWidth - x - width) * scaleX, pixelWidth - MinimumSize - left);
-        int bottom = ToEvenPixel((displayHeight - y - height) * scaleY, pixelHeight - MinimumSize - top);
+        int cropWidth = ToEvenPixel(width * scaleX, pixelWidth - left);
+        int cropHeight = ToEvenPixel(height * scaleY, pixelHeight - top);
+        if (cropWidth < MinimumSize)
+            cropWidth = Math.Min(MinimumSize, pixelWidth - left);
+        if (cropHeight < MinimumSize)
+            cropHeight = Math.Min(MinimumSize, pixelHeight - top);
 
-        if (pixelWidth - left - right < MinimumSize)
-            right = Math.Max(0, pixelWidth - left - MinimumSize);
-        if (pixelHeight - top - bottom < MinimumSize)
-            bottom = Math.Max(0, pixelHeight - top - MinimumSize);
-
-        return new PixelInsets(left, right, top, bottom);
+        return new PixelInsets(left, pixelWidth - left - cropWidth, top, pixelHeight - top - cropHeight);
     }
 
     public static (double X, double Y, double Width, double Height) ToDisplayRect(
@@ -87,6 +101,102 @@ public static class SourceCropSelection
     public static (double X, double Y) ClampToDisplay(double x, double y, double displayWidth, double displayHeight) =>
         (Math.Clamp(x, 0, Math.Max(0, displayWidth)), Math.Clamp(y, 0, Math.Max(0, displayHeight)));
 
+    public static CropHit HitTest(
+        double rectX, double rectY, double rectWidth, double rectHeight, double pointerX, double pointerY, double handleSize)
+    {
+        if (rectWidth <= 0 || rectHeight <= 0 || handleSize < 0)
+            return CropHit.None;
+
+        bool nearLeft = Math.Abs(pointerX - rectX) <= handleSize;
+        bool nearRight = Math.Abs(pointerX - (rectX + rectWidth)) <= handleSize;
+        bool nearTop = Math.Abs(pointerY - rectY) <= handleSize;
+        bool nearBottom = Math.Abs(pointerY - (rectY + rectHeight)) <= handleSize;
+        bool alongX = pointerX >= rectX - handleSize && pointerX <= rectX + rectWidth + handleSize;
+        bool alongY = pointerY >= rectY - handleSize && pointerY <= rectY + rectHeight + handleSize;
+
+        if (nearTop && nearLeft)
+            return CropHit.NorthWest;
+        if (nearTop && nearRight)
+            return CropHit.NorthEast;
+        if (nearBottom && nearLeft)
+            return CropHit.SouthWest;
+        if (nearBottom && nearRight)
+            return CropHit.SouthEast;
+        if (nearTop && alongX)
+            return CropHit.North;
+        if (nearBottom && alongX)
+            return CropHit.South;
+        if (nearLeft && alongY)
+            return CropHit.West;
+        if (nearRight && alongY)
+            return CropHit.East;
+        if (pointerX >= rectX && pointerX <= rectX + rectWidth && pointerY >= rectY && pointerY <= rectY + rectHeight)
+            return CropHit.Move;
+        return CropHit.None;
+    }
+
+    public static (double X, double Y, double Width, double Height) AdjustRect(
+        double x,
+        double y,
+        double width,
+        double height,
+        CropHit hit,
+        double deltaX,
+        double deltaY,
+        double displayWidth,
+        double displayHeight)
+    {
+        const double minSize = 8;
+        double left = x;
+        double top = y;
+        double right = x + width;
+        double bottom = y + height;
+
+        if (hit == CropHit.Move)
+        {
+            left = Math.Clamp(left + deltaX, 0, Math.Max(0, displayWidth - width));
+            top = Math.Clamp(top + deltaY, 0, Math.Max(0, displayHeight - height));
+            return (left, top, width, height);
+        }
+
+        if (hit is CropHit.West or CropHit.NorthWest or CropHit.SouthWest)
+            left = Math.Clamp(left + deltaX, 0, right - minSize);
+        if (hit is CropHit.East or CropHit.NorthEast or CropHit.SouthEast)
+            right = Math.Clamp(right + deltaX, left + minSize, displayWidth);
+        if (hit is CropHit.North or CropHit.NorthWest or CropHit.NorthEast)
+            top = Math.Clamp(top + deltaY, 0, bottom - minSize);
+        if (hit is CropHit.South or CropHit.SouthWest or CropHit.SouthEast)
+            bottom = Math.Clamp(bottom + deltaY, top + minSize, displayHeight);
+
+        return (left, top, Math.Max(minSize, right - left), Math.Max(minSize, bottom - top));
+    }
+
+    public static PixelInsets Nudge(PixelInsets insets, int pixelWidth, int pixelHeight, int deltaX, int deltaY)
+    {
+        int width = pixelWidth - insets.Left - insets.Right;
+        int height = pixelHeight - insets.Top - insets.Bottom;
+        if (width < MinimumSize || height < MinimumSize)
+            return insets;
+
+        int left = ToEvenPixel(insets.Left + deltaX, pixelWidth - width);
+        int top = ToEvenPixel(insets.Top + deltaY, pixelHeight - height);
+        return new PixelInsets(left, pixelWidth - left - width, top, pixelHeight - top - height);
+    }
+
+    public static PixelInsets NudgeEdge(
+        PixelInsets insets, int pixelWidth, int pixelHeight, int dLeft, int dTop, int dRight, int dBottom)
+    {
+        int left = ToEvenPixel(insets.Left + dLeft, pixelWidth - MinimumSize);
+        int top = ToEvenPixel(insets.Top + dTop, pixelHeight - MinimumSize);
+        int right = ToEvenPixel(insets.Right + dRight, pixelWidth - MinimumSize - left);
+        int bottom = ToEvenPixel(insets.Bottom + dBottom, pixelHeight - MinimumSize - top);
+        if (pixelWidth - left - right < MinimumSize)
+            right = Math.Max(0, pixelWidth - left - MinimumSize);
+        if (pixelHeight - top - bottom < MinimumSize)
+            bottom = Math.Max(0, pixelHeight - top - MinimumSize);
+        return new PixelInsets(left, right, top, bottom);
+    }
+
     private static void Normalize(ref double x, ref double y, ref double width, ref double height)
     {
         if (width < 0)

README.md

@@ -120,11 +120,10 @@ process are intentionally left to manual/integration testing rather than unit te
 .\publish-win-x64.ps1
 ```
 
-This publishes a self-contained, single-file `win-x64` executable. At the end of the script
-you'll see the release folder and final executable path, for example:
+This publishes a self-contained, single-file `win-x64` executable and copies it to:
 
 ```text
-bin\Release\net10.0-windows10.0.26100.0\win-x64\publish\AmiReel.exe
+dist\AmiReel.exe
 ```
 
 ## Installation

Services/ShortsPipeline.cs

@@ -160,6 +160,62 @@ public sealed class ShortsPipeline
         await _runner.RunAsync(tools.Ffmpeg, BuildExtractFrameArguments(inputFile, start, outputPath), log, null, token);
     }
 
+    /// <summary>Writes several raw source frames across the clip so the crop editor can switch stills.</summary>
+    public async Task<IReadOnlyList<string>> ExtractSourceFramesAsync(
+        string inputFile,
+        string start,
+        IReadOnlyList<double> offsetsSeconds,
+        string ffmpegPath,
+        string ffprobePath,
+        string outputDirectory,
+        Action<string> log,
+        CancellationToken token)
+    {
+        if (string.IsNullOrWhiteSpace(inputFile) || !File.Exists(inputFile))
+            throw new FileNotFoundException("Select a valid source video for the Short.");
+        if (offsetsSeconds.Count == 0)
+            throw new ArgumentException("At least one preview offset is required.");
+
+        Directory.CreateDirectory(outputDirectory);
+        ToolPaths tools = await ToolExtractor.ResolveAsync(ffmpegPath, ffprobePath, token);
+        List<string> paths = [];
+        for (int index = 0; index < offsetsSeconds.Count; index++)
+        {
+            string seek = AddTimestampOffset(start, offsetsSeconds[index]);
+            string path = Path.Combine(outputDirectory, $"frame-{index:00}.png");
+            log($"Extracting crop preview {index + 1} of {offsetsSeconds.Count} ({seek})...");
+            await _runner.RunAsync(tools.Ffmpeg, BuildExtractFrameArguments(inputFile, seek, path), log, null, token);
+            paths.Add(path);
+        }
+
+        return paths;
+    }
+
+    internal const int CropPreviewFrameCount = 6;
+
+    internal static IReadOnlyList<double> CropPreviewOffsets(double durationSeconds, int count = CropPreviewFrameCount)
+    {
+        if (count <= 1 || durationSeconds <= 0)
+            return [0];
+
+        double last = Math.Max(0, durationSeconds - 0.15);
+        if (last <= 0)
+            return [0];
+
+        double[] offsets = new double[count];
+        for (int index = 0; index < count; index++)
+            offsets[index] = Math.Round(last * index / (count - 1), 3, MidpointRounding.AwayFromZero);
+        return offsets;
+    }
+
+    internal static string FormatPreviewOffsetLabel(double seconds)
+    {
+        TimeSpan value = TimeSpan.FromSeconds(Math.Max(0, seconds));
+        return value.TotalHours >= 1
+            ? value.ToString(@"h\:mm\:ss", CultureInfo.InvariantCulture)
+            : value.ToString(@"m\:ss", CultureInfo.InvariantCulture);
+    }
+
     internal static List<string> BuildExtractFrameArguments(string inputFile, string start, string outputPath) =>
     [
         "-hide_banner",

publish-win-x64.ps1

@@ -16,6 +16,8 @@ $releaseDir = Join-Path $projectDir 'bin\Release\net10.0-windows10.0.26100.0\win
 $releaseExe = Join-Path $releaseDir 'AmiReel.exe'
 $publishDir = Join-Path $releaseDir 'publish'
 $publishExe = Join-Path $publishDir 'AmiReel.exe'
+$distDir = Join-Path $projectDir 'dist'
+$distExe = Join-Path $distDir 'AmiReel.exe'
 $publishArguments = @(
     'publish', $projectPath,
     '-c', 'Release',
@@ -27,11 +29,12 @@ $publishArguments = @(
     '-p:EnableCompressionInSingleFile=true'
 )
 
-if ((Test-Path $releaseExe) -or (Test-Path $publishExe)) {
+if ((Test-Path $releaseExe) -or (Test-Path $publishExe) -or (Test-Path $distExe)) {
     $runningReleaseInstances = Get-Process | Where-Object {
         $_.Path -and (
             [string]::Equals($_.Path, $releaseExe, [System.StringComparison]::OrdinalIgnoreCase) -or
-            [string]::Equals($_.Path, $publishExe, [System.StringComparison]::OrdinalIgnoreCase)
+            [string]::Equals($_.Path, $publishExe, [System.StringComparison]::OrdinalIgnoreCase) -or
+            [string]::Equals($_.Path, $distExe, [System.StringComparison]::OrdinalIgnoreCase)
         )
     }
 
@@ -47,7 +50,16 @@ if (Test-Path $publishDir) {
 }
 
 & dotnet @publishArguments
+if ($LASTEXITCODE -ne 0) {
+    throw "dotnet publish failed with exit code $LASTEXITCODE."
+}
 
-Write-Host "Published AmiReel to $publishDir" -ForegroundColor Green
-Write-Host "Release folder: $publishDir" -ForegroundColor Cyan
-Write-Host "Executable: $publishExe" -ForegroundColor Cyan
+if (-not (Test-Path $publishExe)) {
+    throw "Published executable was not found at $publishExe."
+}
+
+New-Item -ItemType Directory -Path $distDir -Force | Out-Null
+Copy-Item -LiteralPath $publishExe -Destination $distExe -Force
+
+Write-Host "Published AmiReel to $distDir" -ForegroundColor Green
+Write-Host "Executable: $distExe" -ForegroundColor Cyan