C#のWPFアプリで動画再生の速度を制御

プログラミング

MediaElementを使う。

【参照】 C#のFormアプリで動画再生の速度を制御 - 滴了庵日録

MainWindow.xaml

<Window x:Class="MoviePlayer2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Video Speed Control" Height="350" Width="525">
    <Grid>
        <MediaElement x:Name="mediaElement" HorizontalAlignment="Stretch"
                      VerticalAlignment="Stretch" LoadedBehavior="Manual" />

        <Slider x:Name="speedSlider" Minimum="0.1" Maximum="2.0" Value="1.0" 
                TickFrequency="0.1" IsSnapToTickEnabled="True" VerticalAlignment="Bottom" 
                Margin="10" ValueChanged="SpeedSlider_ValueChanged" />
    </Grid>
</Window>

MainWindow.xaml

using System;
using System.Windows;

namespace MoviePlayer2
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            mediaElement.Source = new Uri(@"C:\temp\test.mp4", UriKind.Relative);
            mediaElement.Play();
        }

        private void SpeedSlider_ValueChanged(object sender, 
            RoutedPropertyChangedEventArgs<double> e)
        {
            if (mediaElement != null)
            {
                mediaElement.SpeedRatio = speedSlider.Value;
            }
        }
    }
}

再生位置の取得と設定

    double pos_sec = mediaElement.Position.TotalSeconds;
    Console.WriteLine($"position = {pos_sec}");

    mediaElement.Position = TimeSpan.FromSeconds(pos_sec);