UI fixed: rotation support, ff/bb buttons on preview, inspector layout.

Splitter-UI/Converters/RotationAngleToIconConverter.cs

@@ -0,0 +1,21 @@
+using System.Globalization;
+using Avalonia.Data.Converters;
+
+namespace Splitter_UI.Converters;
+
+public sealed class RotationAngleToIconConverter : IValueConverter
+{
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        return value switch
+        {
+            90  => "\uf2f9",  // FA7 (fa-rotate-left  / fa-arrow-rotate-left  / fa-undo)
+            180 => "\uf2f1",  // FA7 (fa-sync-alt)
+            270 => "\uf2ea",  // FA7 (fa-rotate-right / fa-arrow-rotate-right / fa-redo)
+            _   => null
+        };
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => throw new NotSupportedException();
+}

Splitter-UI/Converters/ZeroToBoolConverter.cs

@@ -0,0 +1,13 @@
+using System.Globalization;
+using Avalonia.Data.Converters;
+
+namespace Splitter_UI.Converters;
+
+public sealed class ZeroToBoolConverter : IValueConverter
+{
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => (value is int i && i == 0);
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => throw new NotSupportedException();
+}

Splitter-UI/Services/IThumbnailService.cs

@@ -5,5 +5,5 @@ namespace Splitter_UI.Services;
 
 public interface IThumbnailService
 {
-    Task<Bitmap?> CreateThumbnailAsync(string file, VideoInfo probe, TimeSpan? skip = null, int? width = null, int? height = null);
+    Task<Bitmap?> CreateThumbnailAsync(string file, VideoInfo probe, TimeSpan? skip = null, int? width = null, int? height = null, int? rotateDegree = null);
 }

Splitter-UI/Services/ThumbnailService.cs

@@ -13,7 +13,13 @@ public sealed class ThumbnailService : IThumbnailService
     private readonly byte [] _bgrBuffer  = new byte[_thumbWidth * _thumbHeight * 3];
     private readonly byte [] _bgraBuffer = new byte[_thumbWidth * _thumbHeight * 4];
 
-    public async Task<Bitmap?> CreateThumbnailAsync(string file, VideoInfo probe, TimeSpan? skip = null, int? width = null, int? height = null)
+    public async Task<Bitmap?> CreateThumbnailAsync(
+        string file,
+        VideoInfo probe,
+        TimeSpan? skip = null,
+        int? width = null,
+        int? height = null,
+        int? rotateDegree = null)
     {
         width  ??= _thumbWidth;
         height ??= _thumbHeight;
@@ -29,7 +35,7 @@ public sealed class ThumbnailService : IThumbnailService
         var bgraBuffer = canUseStaticBuffers ? _bgraBuffer : new byte[width.Value * height.Value * 4];
 
         // Decode a single frame using ffmpeg → raw BGR24 into _bgrBuffer
-        bool ok = await DecodeFrameAsync(bgrBuffer, file, skip.Value, width.Value, height.Value);
+        bool ok = await DecodeFrameAsync(bgrBuffer, file, skip.Value, width.Value, height.Value, rotateDegree);
         if (!ok)
             return null;
 
@@ -37,17 +43,19 @@ public sealed class ThumbnailService : IThumbnailService
         ConvertBgrToBgra(bgrBuffer, bgraBuffer, width.Value, height.Value);
 
         // Create Avalonia Bitmap
-        return CreateBitmap(bgraBuffer, width.Value, height.Value);
+        return CreateBitmap(bgraBuffer, width.Value, height.Value, rotateDegree == 90 || rotateDegree == 270);
     }
 
-    private static async Task<bool> DecodeFrameAsync(byte [] bgrBuffer, string file, TimeSpan skip, int width, int height)
+    private static async Task<bool> DecodeFrameAsync(byte [] bgrBuffer, string file, TimeSpan skip, int width, int height, int? rotateDegree)
     {
+        var rotationStr = TrackingSplitter.GetRorationArg(rotateDegree);
+
         // ffmpeg command: decode one frame, resize, output raw BGR24
         var args =
             $"-ss {skip.TotalSeconds} -t 0.1 -i \"{file}\" " +
             "-an -sn " +
             $"-vf \"scale={width}:{height}:force_original_aspect_ratio=decrease," +
-            $"pad={width}:{height}:(ow-iw)/2:(oh-ih)/2,format=bgr24\" " +
+            $"pad={width}:{height}:(ow-iw)/2:(oh-ih)/2,format=bgr24{rotationStr}\" " +
             "-f rawvideo -";
 
         var psi = new ProcessStartInfo
@@ -107,8 +115,13 @@ public sealed class ThumbnailService : IThumbnailService
         }
     }
 
-    private static unsafe Bitmap CreateBitmap(byte[] bgra, int width, int height)
+    private static unsafe Bitmap CreateBitmap(byte[] bgra, int width, int height, bool isRotated)
     {
+        if (isRotated)
+        {
+            (height, width) = (width, height);
+        }
+
         int stride = width * 4;
 
         fixed (byte* p = bgra)

Splitter-UI/ViewModels/JobViewModel.cs

@@ -41,6 +41,12 @@ public partial class JobViewModel : ObservableObject
 
     public string FileName => Path.GetFileName(Job.InputFile);
 
+    public string TextDesc => Probe != null 
+        ? $"{Probe.Width}x{Probe.Height}, {TimeSpan.FromSeconds(Probe.Duration).ToString(@"hh\:mm\:ss")}), FPS: {Probe.Fps:F2}, Bitrate: {Probe.Bitrate/1024/1024:F2} MB/s"
+        : "";
+
+    public override string ToString() => $"{FileName} - {TextDesc}";
+
     public ObservableCollection<ParameterEntry> ParametersList { get; }
         = new();
 
@@ -105,6 +111,7 @@ public partial class JobViewModel : ObservableObject
         {
             Job.Rotate = value;
             OnPropertyChanged();
+            Task.Run(CreatePreview);
         }
     }
 
@@ -145,7 +152,7 @@ public partial class JobViewModel : ObservableObject
     private async Task LoadThumbnailAsync()
     {
         Probe           = await _fileProbe.ProbeAsync(Job);
-        Thumbnail       = await _thumbnails.CreateThumbnailAsync(Job.InputFile, Probe);
+        Thumbnail       = await _thumbnails.CreateThumbnailAsync(Job.InputFile, Probe, rotateDegree: Job.Rotate);
         SuggestedAction = Probe.Rotation == 0 ? "crop" : "rotate";
 
         await CreatePreview();
@@ -157,9 +164,8 @@ public partial class JobViewModel : ObservableObject
             return;
         try
         {
-            var frame = await _thumbnails.CreateThumbnailAsync(Job.InputFile, Probe, TimeSpan.FromSeconds(PositionSeconds), Probe.Width, Probe.Height);
+            var frame = await _thumbnails.CreateThumbnailAsync(Job.InputFile, Probe, TimeSpan.FromSeconds(PositionSeconds), Probe.Width, Probe.Height, Job.Rotate);
             Preview = new PreviewData(frame, [], null);
-            OnPropertyChanged(nameof(Preview));
         }
         catch (Exception ex)
         {
@@ -197,21 +203,23 @@ public partial class JobViewModel : ObservableObject
 
     private void StepForward()
     {
-        var step = 10.0; // seconds
         if (DurationSeconds <= 0)
             return;
 
-        PositionSeconds = Math.Min(DurationSeconds, PositionSeconds + step);
+        var step = DurationSeconds * 0.1; // 10% of total duration
+
+        SliderLiveValue = Math.Min(DurationSeconds, SliderLiveValue + step);
         // trigger seek in your playback pipeline here
     }
 
     private void StepBackward()
     {
-        var step = 10.0; // seconds
         if (DurationSeconds <= 0)
             return;
 
-        PositionSeconds = Math.Max(0, PositionSeconds - step);
+        var step = DurationSeconds * 0.1; // 10% of total duration
+
+        SliderLiveValue = Math.Max(0, SliderLiveValue - step);
         // trigger seek in your playback pipeline here
     }
 

Splitter-UI/Views/FileListView.axaml

@@ -3,10 +3,15 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:vm="clr-namespace:Splitter_UI.ViewModels"
     xmlns:views="clr-namespace:Splitter_UI.Views"
-    xmlns:svg="clr-namespace:Avalonia.Svg.Skia;assembly=Avalonia.Svg.Skia"
+    xmlns:conv="clr-namespace:Splitter_UI.Converters"
     x:Class="Splitter_UI.Views.FileListView"
     x:DataType="vm:FileListViewModel">
 
+    <UserControl.Resources>
+        <conv:ZeroToBoolConverter x:Key="ZeroToBoolConverter"/>
+        <conv:RotationAngleToIconConverter x:Key="RotationAngleToIconConverter"/>
+    </UserControl.Resources>
+
     <UserControl.Styles>
         <Style Selector="views|FileListView Border#DropZone">
             <Setter Property="BorderBrush" Value="Transparent"/>
@@ -29,7 +34,17 @@
             DragDrop.DragLeave="OnDragLeave">
 
 
+        <Grid>
 
+            <!-- Empty message -->
+            <TextBlock Text="Drag files here"
+                       HorizontalAlignment="Center"
+                       VerticalAlignment="Center"
+                       FontSize="20"
+                       Foreground="#666"
+                       IsVisible="{Binding Files.Count, Converter={StaticResource ZeroToBoolConverter}}"/>
+
+            <!-- File list -->
             <ScrollViewer>
                 <ListBox ItemsSource="{Binding Files}"
                          SelectedItems="{Binding SelectedFiles}"
@@ -71,6 +86,11 @@
                                                        FontSize="12"
                                                        HorizontalAlignment="Right"
                                                        Foreground="LimeGreen"/>
+                                            <TextBlock FontFamily="{StaticResource FontAwesome}"
+                                                       Text="{Binding Rotate, Converter={StaticResource RotationAngleToIconConverter}}"
+                                                       FontSize="12"
+                                                       HorizontalAlignment="Left"
+                                                       Foreground="LimeGreen"/>
                                         </Grid>
                                     </Border>
 
@@ -90,5 +110,6 @@
                     </ListBox.ItemTemplate>
                 </ListBox>
             </ScrollViewer>
+        </Grid>
     </Border>
 </UserControl>

Splitter-UI/Views/InspectorPane.axaml

@@ -12,8 +12,9 @@ x:DataType="vm:InspectorPaneViewModel">
                 <TextBlock Text="Parameters" FontSize="10" Margin="0,0,0,10" FontWeight="Bold"/>
 
                 <!-- InputFile -->
-                <StackPanel Orientation="Horizontal" Spacing="8">
+                <StackPanel Orientation="Vertical" Spacing="8">
-                    <TextBlock Text="{Binding Selected.FileName}" Width="360" Margin="0,0,0,10" FontStyle="Italic"/>
+                    <TextBlock Text="{Binding Selected.FileName}" Width="360" Margin="0,0,0,5" FontStyle="Italic"/>
+                    <TextBlock Text="{Binding Selected.TextDesc}" Width="360" FontSize="10" Margin="0,0,0,10" FontWeight="Bold" Foreground="#676767"/>
                 </StackPanel>
 
                 <!-- Rotate -->
@@ -113,13 +114,22 @@ x:DataType="vm:InspectorPaneViewModel">
                 <DataGrid ItemsSource="{Binding Selected.ParametersList}"
                                 AutoGenerateColumns="False"
                                 HeadersVisibility="Column"
+                                Margin="0,0,20,0"
                                 Height="160">
 
                     <DataGrid.Columns>
 
-                        <DataGridTextColumn Header="Key"
+                        <DataGridTemplateColumn Header="Key" Width="*">
-                                                  Binding="{Binding Key}"
+                            <DataGridTemplateColumn.CellTemplate>
-                                                  Width="*"/>
+                                <DataTemplate>
+                                    <TextBlock Text="{Binding Key}"
+                                               FontSize="10"
+                                               TextTrimming="CharacterEllipsis"
+                                               ToolTip.Tip="{Binding Key}">
+                                    </TextBlock>
+                                </DataTemplate>
+                            </DataGridTemplateColumn.CellTemplate>
+                        </DataGridTemplateColumn>
 
                         <DataGridTemplateColumn Header="Value" Width="2*">
                             <DataGridTemplateColumn.CellTemplate>

Splitter-UI/Views/MainWindow.axaml

@@ -6,7 +6,7 @@
     x:Class="Splitter_UI.Views.MainWindow"
     x:DataType="vm:MainViewModel"
     Width="1400"
-    Height="900"
+    Height="950"
     Title="Splitter UI">
 
     <DockPanel>
@@ -20,7 +20,7 @@
                        DataContext="{Binding LogPane}" />
 
         <!-- Main Content -->
-        <Grid ColumnDefinitions="2*,3*,2*">
+        <Grid ColumnDefinitions="2*,3*,430">
 
             <!-- File List -->
             <views:FileListView Grid.Column="0"

splitter-cli/TrackingSplitter.cs

@@ -170,16 +170,7 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
         var ss = start .ToString("0.###", CultureInfo.InvariantCulture);
         var t  = length.ToString("0.###", CultureInfo.InvariantCulture);
 
-        var rotateStr = "";
+        var rotateStr = GetRorationArg(rotate);
-        if (rotate != null)
-        {
-            switch (rotate.Value)
-            {
-                case 90:  rotateStr = ",transpose=1";  break;
-                case 180: rotateStr = ",transpose=PI"; break;
-                case 270: rotateStr = ",transpose=2";  break;
-            }
-        }
 
         var args =
     $"-i \"{inputFile}\" -ss {ss} -t {t} " +
@@ -217,6 +208,22 @@ public class TrackingSplitter : LoggingBase, ISegmentProcessor, IDisposable
         return p;
     }
 
+    public static string GetRorationArg(int? rotate)
+    {
+        var rotateStr = "";
+        if (rotate != null)
+        {
+            switch (rotate.Value)
+            {
+                case 90: rotateStr = ",transpose=1"; break;
+                case 180: rotateStr = ",transpose=PI"; break;
+                case 270: rotateStr = ",transpose=2"; break;
+            }
+        }
+
+        return rotateStr;
+    }
+
     private Process StartFfmpegEncode(
         string inputFile,
         string outputFile,