MainWindow.xaml

<Window x:Class="VideoCutter.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:VideoCutter"
        mc:Ignorable="d"
        Title="VideoCutter" Height="450" Width="800">
    <TabControl Name="MainWindowTabControl" TabStripPlacement="Top" Margin="5,5,5,5">
        <TabItem Header="Cut video" >
            <local:Cutter Loaded="Cutter_Loaded" />
        </TabItem>
        <TabItem Header="Merge video">
            <local:Merger />
        </TabItem>
        <TabItem Header="Extract tracks">
            <local:Extractor />
        </TabItem>
        <TabItem Header="Settings">
            <local:Settings />
        </TabItem>
        <TabItem Header="About">
            <local:About />
        </TabItem>
    </TabControl>
</Window>