WPFで動画ファイルを再生するサンプル2「チャプター」

<Window x:Class="VideoPlayer01.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:VideoPlayer01"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <StackPanel Orientation="Horizontal" Grid.Row="0" HorizontalAlignment="Center">
            <TextBox x:Name="MovieFileTextBox" Height="30" Margin="10" Width="400"></TextBox>
            <Button x:Name="FileSelectButton" Height="30" Margin="10" Width="100" Click="FileSelect">ファイル選択</Button>
        </StackPanel>
        <MediaElement
            x:Name="MovieControl"
            Grid.Row="1"
            LoadedBehavior="Manual"
            UnloadedBehavior="Stop">
        </MediaElement>
        <StackPanel Orientation="Horizontal" Grid.Row="2" HorizontalAlignment="Center">
            <Button x:Name="PlayButton" Height="30" Width="100" Margin="10" Click="PlayClick">再生</Button>
            <Button x:Name="PauseButton" Height="30" Width="100" Margin="10" Click="PauseClick">一時停止</Button>
            <Button x:Name="StopButton" Height="30" Width="100" Margin="10" Click="StopClick">停止</Button>
            <Button x:Name="NextButton" Height="30" Width="100" Margin="10" Click="NextClick">次へ</Button>
        </StackPanel>
    </Grid>
</Window>

using System.Diagnostics;
using System.Text.RegularExpressions;
using System.Windows;
using Microsoft.Win32;

namespace VideoPlayer01;

/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public List<TimeSpan> Chapters = [];
    static List<TimeSpan> getMetadata(string filePath)
    {
        var proc = new Process();
        string str = "";
        proc.StartInfo.FileName = "ffprobe.exe"; 
        proc.StartInfo.Arguments = string.Format("-i {0} -hide_banner", "\"" +filePath + "\"");
        proc.StartInfo.CreateNoWindow = true; 
        proc.StartInfo.UseShellExecute = false; 
        proc.StartInfo.RedirectStandardError = true; 
        proc.Start(); 
        str = proc.StandardError.ReadToEnd(); 
        proc.WaitForExit(); 
        proc.Close();

        List<TimeSpan> result = new();
        
        string[] del = ["\n"];
        string pattern = @"\s+Chapter\s#\d+:\d+:\sstart\s(\d+\.\d+),";
        var reg = new Regex(pattern);
        foreach(var row in str.Split(del, StringSplitOptions.None))
        {
            var matches = reg.Matches(row);
            if (matches.Count == 0) continue;
            string v = matches[0].Groups[1].ToString();
            double d = double.Parse(v);
            long l = (long)(d * 10000000.0d);
            TimeSpan ts = new TimeSpan(l);
            result.Add(ts);
        }

        return result;
    }
    public MainWindow()
    {
        InitializeComponent();
    }
    public void FileSelect(object sender, EventArgs e)
    {
        var d =new OpenFileDialog();
        d.InitialDirectory = @"c:\";
        d.ShowDialog();

        Chapters = getMetadata(d.FileName);
        MovieFileTextBox.Text = d.FileName;
        MovieControl.Source = new Uri(MovieFileTextBox.Text);
    }
    public void PlayClick(object sender, EventArgs e)
    {
        if (MovieFileTextBox.Text == "") return;
        MovieControl.Play();
    }
    public void PauseClick(object sender, EventArgs e)
    {
        MovieControl.Pause();
    }
    public void StopClick(object sender, EventArgs e)
    {
        MovieControl.Stop();
    }
    public void NextClick(object sender, EventArgs e)
    {
        //Debug.Print($"{MovieControl.Position}");
        var cur = MovieControl.Position;
        foreach(var ts in Chapters)
        {
            if (ts > cur)
            {
                MovieControl.Position = ts;
                break;
            }
        }
    }
}