diff --git a/BililiveRecorder.WPF/BililiveRecorder.WPF.csproj b/BililiveRecorder.WPF/BililiveRecorder.WPF.csproj
index f3eb15a..28935a8 100644
--- a/BililiveRecorder.WPF/BililiveRecorder.WPF.csproj
+++ b/BililiveRecorder.WPF/BililiveRecorder.WPF.csproj
@@ -144,6 +144,9 @@
     <Compile Include="Pages\ToolboxAutoFixPage.xaml.cs">
       <DependentUpon>ToolboxAutoFixPage.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Pages\ToolboxRemuxPage.xaml.cs">
+      <DependentUpon>ToolboxRemuxPage.xaml</DependentUpon>
+    </Compile>
     <Compile Include="Program.cs" />
     <Compile Include="SingleInstance.cs" />
     <Compile Include="Properties\Strings.Designer.cs">
@@ -242,6 +245,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="Pages\ToolboxRemuxPage.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="Resources\ConverterResources.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -287,6 +294,9 @@
       <LastGenOutput>Strings.Designer.cs</LastGenOutput>
     </EmbeddedResource>
     <EmbeddedResource Include="Properties\Strings.zh-Hant.resx" />
+    <None Include="lib\miniffmpeg">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Include="Properties\app.manifest" />
     <Resource Include="ico.ico" />
   </ItemGroup>
@@ -308,6 +318,9 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <PackageReference Include="CliWrap">
+      <Version>3.3.2</Version>
+    </PackageReference>
     <PackageReference Include="GitVersion.MsBuild" Version="5.6.6">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
diff --git a/BililiveRecorder.WPF/Pages/RootPage.xaml b/BililiveRecorder.WPF/Pages/RootPage.xaml
index b9f6a4d..a020e12 100644
--- a/BililiveRecorder.WPF/Pages/RootPage.xaml
+++ b/BililiveRecorder.WPF/Pages/RootPage.xaml
@@ -102,6 +102,12 @@
                                 <ui:PathIcon Style="{StaticResource PathIconDataAutoFix}"/>
                             </ui:NavigationViewItem.Icon>
                         </ui:NavigationViewItem>
+                        <ui:NavigationViewItem l:ResxLocalizationProvider.DefaultDictionary="Strings" 
+                                               Content="{l:Loc Toolbox_Remux_Title}" Tag="ToolboxRemuxPage">
+                            <ui:NavigationViewItem.Icon>
+                                <ui:PathIcon Style="{StaticResource PathIconDataAlphaRCircleOutline}"/>
+                            </ui:NavigationViewItem.Icon>
+                        </ui:NavigationViewItem>
                     </ui:NavigationViewItem.MenuItems>
                 </ui:NavigationViewItem>
             </ui:NavigationView.MenuItems>
diff --git a/BililiveRecorder.WPF/Pages/RootPage.xaml.cs b/BililiveRecorder.WPF/Pages/RootPage.xaml.cs
index 609c5cd..9fa73ec 100644
--- a/BililiveRecorder.WPF/Pages/RootPage.xaml.cs
+++ b/BililiveRecorder.WPF/Pages/RootPage.xaml.cs
@@ -53,6 +53,7 @@ namespace BililiveRecorder.WPF.Pages
             AddType(typeof(AdvancedSettingsPage));
             AddType(typeof(AnnouncementPage));
             AddType(typeof(ToolboxAutoFixPage));
+            AddType(typeof(ToolboxRemuxPage));
 
             this.Model = new RootModel();
             this.DataContext = this.Model;
diff --git a/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml b/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml
new file mode 100644
index 0000000..0cc29d4
--- /dev/null
+++ b/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml
@@ -0,0 +1,42 @@
+<ui:Page
+    x:Class="BililiveRecorder.WPF.Pages.ToolboxRemuxPage"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:ui="http://schemas.modernwpf.com/2019"
+    xmlns:l="https://github.com/XAMLMarkupExtensions/WPFLocalizationExtension"
+    l:LocalizeDictionary.DesignCulture=""
+    l:ResxLocalizationProvider.DefaultAssembly="BililiveRecorder.WPF"
+    l:ResxLocalizationProvider.DefaultDictionary="Strings"
+    xmlns:local="clr-namespace:BililiveRecorder.WPF.Pages"
+    xmlns:model="clr-namespace:BililiveRecorder.WPF.Models"
+    xmlns:c="clr-namespace:BililiveRecorder.WPF.Converters"
+    mc:Ignorable="d" 
+    d:DesignHeight="450" d:DesignWidth="800"
+    Title="ToolboxRemuxPage">
+    <Grid>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+        </Grid.RowDefinitions>
+        <Button Margin="10" Padding="10" FontSize="20" HorizontalAlignment="Center" Content="{l:Loc Toolbox_Remux_Title}" Click="RemuxButton_Click"/>
+        <TextBlock Grid.Row="1" TextAlignment="Center">
+            用法
+            <LineBreak/>
+            1. 点击上面的转封装按钮<LineBreak/>
+            2. 选择要转封装的 FLV 文件<LineBreak/>
+            3. 选择 MP4 保存位置<LineBreak/>
+            <LineBreak/>
+            说明
+            <LineBreak/>
+            本工具基于 FFmpeg 实现，只提供最基本的转封装功能。<LineBreak/>
+            只支持从 FLV 转封装到 MP4，如需其他格式请使用其他工具。<LineBreak/>
+            转封装时会占满硬盘IO，可能导致正在进行的录播中断。<LineBreak/>
+            转封装大文件会花一两分钟时间，请耐心等待。<LineBreak/>
+            如果录播文件存在问题，请先用录播修复工具修复后再转封装。<LineBreak/>
+            如果文件存在问题，转封装后就无法修复了。<LineBreak/>
+            标准录制模式录出来的文件不需要手动修复。
+        </TextBlock>
+    </Grid>
+</ui:Page>
diff --git a/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml.cs b/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml.cs
new file mode 100644
index 0000000..3ad7fef
--- /dev/null
+++ b/BililiveRecorder.WPF/Pages/ToolboxRemuxPage.xaml.cs
@@ -0,0 +1,110 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using System.Windows;
+using CliWrap;
+using CliWrap.Buffered;
+using Microsoft.WindowsAPICodePack.Dialogs;
+using Serilog;
+using WPFLocalizeExtension.Extensions;
+
+namespace BililiveRecorder.WPF.Pages
+{
+    /// <summary>
+    /// Interaction logic for ToolboxRemuxPage.xaml
+    /// </summary>
+    public partial class ToolboxRemuxPage
+    {
+        private static readonly ILogger logger = Log.ForContext<ToolboxRemuxPage>();
+        private static readonly string DesktopPath = Environment.GetFolderPath(Environment.SpecialFolder.Desktop);
+        private static readonly string FFmpegWorkingDirectory;
+        private static readonly string FFmpegPath;
+
+        static ToolboxRemuxPage()
+        {
+            FFmpegWorkingDirectory = Path.Combine(Path.GetDirectoryName(typeof(ToolboxRemuxPage).Assembly.Location), "lib");
+            FFmpegPath = Path.Combine(FFmpegWorkingDirectory, "miniffmpeg");
+        }
+
+        public ToolboxRemuxPage()
+        {
+            this.InitializeComponent();
+        }
+
+#pragma warning disable VSTHRD100 // Avoid async void methods
+        private async void RemuxButton_Click(object sender, RoutedEventArgs e)
+#pragma warning restore VSTHRD100 // Avoid async void methods
+        {
+            try
+            {
+                await this.RunAsync();
+            }
+            catch (Exception ex)
+            {
+                logger.Warning(ex, "转封装时发生未知错误");
+            }
+        }
+
+        private async Task RunAsync()
+        {
+            string source, target;
+
+            {
+
+                var d = new CommonOpenFileDialog()
+                {
+                    Title = LocExtension.GetLocalizedValue<string>("BililiveRecorder.WPF:Strings:Toolbox_Remux_OpenFileTitle"),
+                    AllowNonFileSystemItems = false,
+                    DefaultDirectory = DesktopPath,
+                    DefaultExtension = "flv",
+                    EnsureFileExists = true,
+                    EnsurePathExists = true,
+                    EnsureValidNames = true,
+                    Multiselect = false,
+                };
+
+                d.Filters.Add(new CommonFileDialogFilter("FLV", "*.flv"));
+
+                if (d.ShowDialog() != CommonFileDialogResult.Ok)
+                    return;
+
+                source = d.FileName;
+            }
+
+            {
+                var d = new CommonSaveFileDialog()
+                {
+                    Title = LocExtension.GetLocalizedValue<string>("BililiveRecorder.WPF:Strings:Toolbox_Remux_SaveFileTitle"),
+                    AlwaysAppendDefaultExtension = true,
+                    DefaultDirectory = DesktopPath,
+                    DefaultExtension = "mp4",
+                    EnsurePathExists = true,
+                    EnsureValidNames = true,
+                    InitialDirectory = Path.GetDirectoryName(source),
+                    DefaultFileName = Path.GetFileNameWithoutExtension(source),
+                };
+
+                d.Filters.Add(new CommonFileDialogFilter("MP4", "*.mp4"));
+
+                if (d.ShowDialog() != CommonFileDialogResult.Ok)
+                    return;
+
+                target = d.FileName;
+            }
+
+            logger.Debug("Remux starting, {Source}, {Target}", source, target);
+
+            var result = await Cli.Wrap(FFmpegPath)
+                .WithValidation(CommandResultValidation.None)
+                .WithWorkingDirectory(FFmpegWorkingDirectory)
+                .WithArguments(new[] { "-hide_banner", "-loglevel", "error", "-y", "-i", source, "-c", "copy", target })
+#if DEBUG
+                .ExecuteBufferedAsync();
+#else
+                .ExecuteAsync();
+#endif
+
+            logger.Debug("Remux completed {@Result}", result);
+        }
+    }
+}
diff --git a/BililiveRecorder.WPF/Properties/Strings.Designer.cs b/BililiveRecorder.WPF/Properties/Strings.Designer.cs
index 0928be3..b929611 100644
--- a/BililiveRecorder.WPF/Properties/Strings.Designer.cs
+++ b/BililiveRecorder.WPF/Properties/Strings.Designer.cs
@@ -1567,6 +1567,33 @@ namespace BililiveRecorder.WPF.Properties {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to 选择需要转封装的 FLV 文件.
+        /// </summary>
+        public static string Toolbox_Remux_OpenFileTitle {
+            get {
+                return ResourceManager.GetString("Toolbox_Remux_OpenFileTitle", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to 选择 MP4 文件保存位置.
+        /// </summary>
+        public static string Toolbox_Remux_SaveFileTitle {
+            get {
+                return ResourceManager.GetString("Toolbox_Remux_SaveFileTitle", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to 转封装.
+        /// </summary>
+        public static string Toolbox_Remux_Title {
+            get {
+                return ResourceManager.GetString("Toolbox_Remux_Title", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to 工具箱.
         /// </summary>
diff --git a/BililiveRecorder.WPF/Properties/Strings.resx b/BililiveRecorder.WPF/Properties/Strings.resx
index 90fe731..997c3fd 100644
--- a/BililiveRecorder.WPF/Properties/Strings.resx
+++ b/BililiveRecorder.WPF/Properties/Strings.resx
@@ -647,6 +647,15 @@ Will use default setting and disable user input when checked.</comment>
   <data name="Toolbox_AutoFix_Title" xml:space="preserve">
     <value>录播修复</value>
   </data>
+  <data name="Toolbox_Remux_OpenFileTitle" xml:space="preserve">
+    <value>选择需要转封装的 FLV 文件</value>
+  </data>
+  <data name="Toolbox_Remux_SaveFileTitle" xml:space="preserve">
+    <value>选择 MP4 文件保存位置</value>
+  </data>
+  <data name="Toolbox_Remux_Title" xml:space="preserve">
+    <value>转封装</value>
+  </data>
   <data name="Toolbox_Title" xml:space="preserve">
     <value>工具箱</value>
   </data>
diff --git a/BililiveRecorder.WPF/Resources/IconResources.xaml b/BililiveRecorder.WPF/Resources/IconResources.xaml
index 55b35c1..7e87ed2 100644
--- a/BililiveRecorder.WPF/Resources/IconResources.xaml
+++ b/BililiveRecorder.WPF/Resources/IconResources.xaml
@@ -91,6 +91,9 @@
     <Style TargetType="ui:PathIcon" x:Key="PathIconDataBugOutline">
         <Setter Property="Data" Value="M20,8H17.19C16.74,7.2 16.12,6.5 15.37,6L17,4.41L15.59,3L13.42,5.17C12.96,5.06 12.5,5 12,5C11.5,5 11.05,5.06 10.59,5.17L8.41,3L7,4.41L8.62,6C7.87,6.5 7.26,7.21 6.81,8H4V10H6.09C6.03,10.33 6,10.66 6,11V12H4V14H6V15C6,15.34 6.03,15.67 6.09,16H4V18H6.81C8.47,20.87 12.14,21.84 15,20.18C15.91,19.66 16.67,18.9 17.19,18H20V16H17.91C17.97,15.67 18,15.34 18,15V14H20V12H18V11C18,10.66 17.97,10.33 17.91,10H20V8M16,15A4,4 0 0,1 12,19A4,4 0 0,1 8,15V11A4,4 0 0,1 12,7A4,4 0 0,1 16,11V15M14,10V12H10V10H14M10,14H14V16H10V14Z"/>
     </Style>
+    <Style TargetType="ui:PathIcon" x:Key="PathIconDataAlphaRCircleOutline">
+        <Setter Property="Data" Value="M9,7H13A2,2 0 0,1 15,9V11C15,11.84 14.5,12.55 13.76,12.85L15,17H13L11.8,13H11V17H9V7M11,9V11H13V9H11M12,2A10,10 0 0,1 22,12A10,10 0 0,1 12,22A10,10 0 0,1 2,12A10,10 0 0,1 12,2M12,4A8,8 0 0,0 4,12C4,16.41 7.58,20 12,20A8,8 0 0,0 20,12A8,8 0 0,0 12,4Z"/>
+    </Style>
     <Style TargetType="ui:PathIcon" x:Key="PathIconData">
         <Setter Property="Data" Value=""/>
     </Style>
diff --git a/BililiveRecorder.WPF/lib/miniffmpeg b/BililiveRecorder.WPF/lib/miniffmpeg
new file mode 100644
index 0000000..a11b219
Binary files /dev/null and b/BililiveRecorder.WPF/lib/miniffmpeg differ