diff --git a/BilibiliLiveRecordDownLoader/ViewModels/FFmpegCommandViewModel.cs b/BilibiliLiveRecordDownLoader/ViewModels/FFmpegCommandViewModel.cs
index c92d611..2673bb4 100644
--- a/BilibiliLiveRecordDownLoader/ViewModels/FFmpegCommandViewModel.cs
+++ b/BilibiliLiveRecordDownLoader/ViewModels/FFmpegCommandViewModel.cs
@@ -84,6 +84,19 @@ public FFmpegCommandViewModel(
 			ConvertOpenFileCommand = ReactiveCommand.Create(ConvertOpenFile);
 			ConvertSaveFileCommand = ReactiveCommand.Create(ConvertSaveFile);
 			ConvertCommand = ReactiveCommand.Create(CreateConvertVideoTask);
+
+			this.WhenAnyValue(x => x.CutInput).Subscribe(_ =>
+			{
+				NewOutputFile();
+			});
+
+			this.WhenAnyValue(x => x.ConvertInput).Subscribe(file =>
+			{
+				if (Path.GetExtension(file) == @".flv")
+				{
+					ConvertOutput = Path.ChangeExtension(file, @"mp4");
+				}
+			});
 		}
 
 		private async Task<bool> CheckFFmpegStatusAsync(CancellationToken token)
@@ -113,6 +126,10 @@ private async Task<bool> CheckFFmpegStatusAsync(CancellationToken token)
 		private void NewOutputFile()
 		{
 			var filename = CutInput;
+			if (!File.Exists(filename))
+			{
+				return;
+			}
 
 			var oldName = Path.ChangeExtension(filename, null);
 			var extension = Path.GetExtension(filename);
@@ -146,8 +163,6 @@ private void CutOpenFile()
 			}
 
 			CutInput = filename;
-
-			NewOutputFile();
 		}
 
 		private void CutSaveFile()
@@ -170,11 +185,6 @@ private void ConvertOpenFile()
 			}
 
 			ConvertInput = filename;
-
-			if (Path.GetExtension(filename) == @".flv")
-			{
-				ConvertOutput = Path.ChangeExtension(filename, @"mp4");
-			}
 		}
 
 		private void ConvertSaveFile()
diff --git a/BilibiliLiveRecordDownLoader/Views/FFmpegCommandView.xaml.cs b/BilibiliLiveRecordDownLoader/Views/FFmpegCommandView.xaml.cs
index e0df256..56c9303 100644
--- a/BilibiliLiveRecordDownLoader/Views/FFmpegCommandView.xaml.cs
+++ b/BilibiliLiveRecordDownLoader/Views/FFmpegCommandView.xaml.cs
@@ -20,12 +20,12 @@ public FFmpegCommandView(FFmpegCommandViewModel viewModel)
 				this.OneWayBind(ViewModel, vm => vm.FFmpegStatusForeground, vm => vm.FFmpegStatusTextBlock.Foreground).DisposeWith(d);
 				this.BindCommand(ViewModel, vm => vm.CheckFFmpegStatusCommand, vm => vm.FFmpegStatusTextBlock, nameof(FFmpegStatusTextBlock.MouseLeftButtonUp)).DisposeWith(d);
 
-				this.OneWayBind(ViewModel, vm => vm.CutInput, vm => vm.CutInputTextBox.Text).DisposeWith(d);
+				this.Bind(ViewModel, vm => vm.CutInput, vm => vm.CutInputTextBox.Text).DisposeWith(d);
 				this.Bind(ViewModel, vm => vm.CutOutput, vm => vm.CutOutputTextBox.Text).DisposeWith(d);
 				this.Bind(ViewModel, vm => vm.CutStartTime, vm => vm.CutStartTimeTextBox.Text).DisposeWith(d);
 				this.Bind(ViewModel, vm => vm.CutEndTime, vm => vm.CutEndTimeTextBox.Text).DisposeWith(d);
 
-				this.OneWayBind(ViewModel, vm => vm.ConvertInput, vm => vm.ConvertInputTextBox.Text).DisposeWith(d);
+				this.Bind(ViewModel, vm => vm.ConvertInput, vm => vm.ConvertInputTextBox.Text).DisposeWith(d);
 				this.Bind(ViewModel, vm => vm.ConvertOutput, vm => vm.ConvertOutputTextBox.Text).DisposeWith(d);
 				this.Bind(ViewModel, vm => vm.IsDelete, vm => vm.IsDeleteToggleSwitch.IsOn).DisposeWith(d);