WPF中使用LibVLCSharp.WPF 播放rtsp
LibVLCSharp.WPF简介
从vlc说起
-
vlc是一个开源的跨平台视频播放库,使用C/C++编写,vlc底层基于ffmpeg。地址:https://github.com/videolan/vlc
-
LibVLC是对vlc的封装,提供了开发的灵活性、便捷性,统一和更加高级的api。C/C++编写。地址:https://code.videolan.org/videolan/libvlc-nuget
LibVLC支持的平台:
平台 | LibVLC包 | Nuget地址 | 最低操作系统版本 |
---|---|---|---|
Windows | VideoLAN.LibVLC.Windows | https://www.nuget.org/packages/VideoLAN.LibVLC.Windows/ | Windows XP |
UWP | VideoLAN.LibVLC.UWP | https://www.nuget.org/packages/VideoLAN.LibVLC.UWP/ | Windows 10 |
Mac | VideoLAN.LibVLC.Mac | https://www.nuget.org/packages/VideoLAN.LibVLC.Mac/ | macOS 10.7 |
Android | VideoLAN.LibVLC.Android | https://www.nuget.org/packages/VideoLAN.LibVLC.Android/ | Android 2.3 |
iOS | VideoLAN.LibVLC.iOS | https://www.nuget.org/packages/VideoLAN.LibVLC.iOS/ | iOS 8.4 |
tvOS | VideoLAN.LibVLC.tvOS | https://www.nuget.org/packages/VideoLAN.LibVLC.tvOS/ | tvOS 10.2 |
Linux | LinuxGuide:https://code.videolan.org/videolan/LibVLCSharp/-/blob/3.x/docs/linux-setup.md |
-
LibVLCSharp是对LibVLC的封装,相当于一个包装器,提供给C#开发人员使用LibVLC的功能。地址:https://code.videolan.org/videolan/LibVLCSharp
-
LibVLCSharp.WPF是LibVLCSharp的WPF实现,封装了vlc:VideoView 这个UI控件,用来播放视频。 LibVLCSharp.WPF可以在.NETCoreApp 3.1 ;.NETFramework 4.6.1+; net6.0+运行时中使用。
虽然 LibVLCSharp 提供跨平台的解决方案,但是本文主要基于 Windows 平台来讨论。
vlc:VideoView基本使用
安装LibVLC
在使用LIibVLCSharp.WPF前必须先安装 LibVLC,否则会报如下错误:
//报错位置:实例化 LibVLC
LibVLC _libvlc=new LibVLC();
//Message:
Failed to load required native libraries.
Have you installed the latest LibVLC package from nuget for your target platform?
Search paths include E:\code\WPF\APngApp\bin\Debug\net7.0-windows\libvlc\win-x64\libvlc.dll,E:\code\WPF\APngApp\bin\Debug\net7.0-windows\libvlc\win-x64\libvlccore.dll; E:\code\WPF\APngApp\bin\Debug\net7.0-windows\libvlc\win-x64\libvlc.dll,E:\code\WPF\APngApp\bin\Debug\net7.0-windows\libvlc\win-x64\libvlccore.dll; E:\code\WPF\APngApp\bin\Debug\net7.0-windows\libvlc.dll,
LibVLC安装方式:
- 集成安装:LibVLC 已经打包成了一个package,放在了nuget上面,只需要在项目中安装此VideoLAN.LibVLC.Windows依赖就可以。nuget安装命令:NuGet\Install-Package VideoLAN.LibVLC.Windows
播放rtsp
新建 wpf 应用程序
引入命名空间
xmlns:vlc="clr-namespace:LibVLCSharp.WPF;assembly=LibVLCSharp.WPF"
xaml 代码
<vlc:VideoView x:Name="video_main" >
......
</vlc:VideoView>
cs代码
private void MainWindow_Loaded(object sender, RoutedEventArgs e)
{
LibVLC _libvlc = new LibVLC();
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
video_main.Width = this.Width;
video_main.Height = this.Height;
video_main.MediaPlayer = player;
//通过设置宽高比为窗体宽高可达到视频铺满全屏的效果
player.AspectRatio = this.Width + ":" + this.Height;
string url = "rtsp://user:password@192.168.1.120:554/ch1/main/av_stream";
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
video_main.MediaPlayer.Play(media);
}
}
截图
概述
LibVLCSharp是对 vlc 的封装,而vlc本身就支持截图的功能,相应的LibVLCSharp也提供了一个 MediaPlayer.TakeSnapshot 的方法用来截图
调用该方法需要传递的参数:
- num:视频输出数量(通常第一个/仅一个为0)【直译过来的,这个参数具体什么意思尚不太清楚,当前是直接传0】
- filePath:图片文件存放路径,需要确保文件夹存在并有访问权限,如:D:\A\2.png
- width:图片的宽度
- height:图片的高度
- 若宽高都为0,则生成的图片为视频原始大小;若宽为0或者高为0,则生成的图片为视频原始的纵横比
代码示例
在页面添加一个按钮,在按钮点击事件中处理截图。
xaml:
<Label Width="70" Height="70" Margin="5,0,5,0" Name="snapshot" MouseLeftButtonDown="snapshot_MouseLeftButtonDown" Cursor="Hand">
<Label.Background>
<ImageBrush ImageSource="/Images/small_video_hide.png" Stretch="Uniform"/>
</Label.Background>
</Label>
cs:
private void snapshot_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
string dirPath = AppDomain.CurrentDomain.BaseDirectory+ "\\snapshot\\";
//string dirPath = "D:\\A\\";
string imgName = DateTime.Now.Ticks+ ".png";
string filePath = dirPath + imgName;
bool r = this.video_main.MediaPlayer.TakeSnapshot(0, filePath, (uint)this.video_main.Width, (uint)this.video_main.Height);
}
- video_main 就是 VideoView 控件的name
vlc:VideoView进阶使用
空域问题
由于VideoView控件的实现原理是在window上面绑定一个前台窗体(ForegroudWindow),然后在ForegroudWindow中播放视频,所以当需要在window中添加其他控件(如:label,button......)的时候不可以使用WPF原始的“并列”写法,而需要使用“层级”写法,即将需要展示的控件写在VideoView控件的"里面",他们形成父子级关系。
上述文字可能比较难以理解, 用代码来分析。首先通过编写如下代码,让视频播放起来:
xaml:
<Window x:Class="APngApp.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:vlc="clr-namespace:LibVLCSharp.WPF;assembly=LibVLCSharp.WPF"
xmlns:local="clr-namespace:APngApp"
mc:Ignorable="d"
xmlns:apngPlayer="clr-namespace:ImoutoRebirth.Navigator.ApngWpfPlayer.ApngPlayer;assembly=ImoutoRebirth.Navigator.ApngWpfPlayer"
Title="MainWindow" Height="1200" Width="2300" Loaded="Window_Loaded">
<Grid>
<DockPanel>
<vlc:VideoView Name="videoView">
<Button x:Name="btn_test" Width="200" Height="100" Content="我是一个测试用的按钮" >
</Button>
</vlc:VideoView>
</DockPanel>
</Grid>
</Window>
cs:
using LibVLCSharp.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Policy;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace APngApp
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
private LibVLC _libvlc;
public MainWindow()
{
InitializeComponent();
_libvlc=new LibVLC();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
videoView.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri("rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream")))
{
videoView.MediaPlayer.Play(media);
}
}
}
}
如果一切正常,将看到如下的画面,并且在VS实时可视化树中将看到 ForegroudWindow 和 MainWindow。
- 可以看到虽然我们仅仅创建了一个MainWindow,但是确实有两个窗体存在,VideoView控件为程序生成了一个ForegroudWindow。
- 当我们在VideoView内部编写一个button控件的时候,控件正确的显示出来了,如果我们将这个button移动到和vlc:VideoView并列的位置,按钮将不会显示出来,因为它被ForegroudWindow遮住了,这很诡异,也很有趣,这里就不列举并列写法的代码了。
- 官方(videolan)把这种情况总结为空域问题,即 Airspace。
- 不难看出来VideoView控件的这种设计有悖常理,但是据说这是由于LibVLC和vlc的局限性导致的,属于妥协式设计。但是大可放心使用,LibVLCSharp这套解决方案使用非常的广泛,而且截至目前(2023)官方issues仍非常活跃,并且版本也在不断更新中。官方也提供商业版本和付费的技术支持。
宽高比设置
宽高比设置是一个非常神奇的功能,它可以解决:
- 想让画面全屏显示却出现了间隙,这里的间隙是指画面没有完全覆盖窗体。
- 想要挤压或者拉伸画面却不知道如何实现。
- 在异形屏幕上面全屏显示画面,如:画面比例是16:9,想要在分辨率为5:5的屏幕上面全屏显示画面
- 其他宽高比问题,实际生产中,画面宽高比和屏幕宽高比都是不固定的,甚至可以说很随意,比如海康全景相机,其输出的画面本身就是宽度远高于高度,再比如同一个WPF程序需要在分辨率为1366768和25601440的屏幕分辨率下面全屏显示
- 这里提到的画面是指rtsp源本身的画面大小
通过如下代码和现象可以很直观的观察到宽高比的神奇之处。
全屏问题
环境:Windows11,屏幕分辨率为2560*1440,未设置缩放
-
新建一个WPF的窗体,引入VideoView控件,并在Window_ContentRendered 事件中初始化 MediaPlayer 以播放rtsp流。
-
为尽可能排除其他因素对本问题的影响,将对窗体和VideoView控件做如下初始化设置:
- 窗体的WindowStyle=None
- 窗体的ResizeMode=NoResize
- 窗体的AllowTransparency=true
- 设置窗体初始宽高为屏幕工作区域,即不包括任务栏部分,此时实际高度小于1440
- 设置video控件的 宽高为窗体的宽高
xaml代码:
<Window x:Class="RambleWPF.视频控件3"
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:RambleWPF"
mc:Ignorable="d"
Title="视频控件3" Height="450" Width="800"
xmlns:vlc="clr-namespace:LibVLCSharp.WPF;assembly=LibVLCSharp.WPF" ContentRendered="Window_ContentRendered"
Name="win"
>
<Window.Resources>
<Style x:Key="BtnInfoStyle" TargetType="Button">
<Setter Property="Width" Value="70"/>
<Setter Property="Height" Value="25"/>
<Setter Property="Foreground" Value="White"/>
<Setter Property="BorderThickness" Value="0"/>
<Setter Property="Background" Value="#43a9c7"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Border x:Name="border" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" SnapsToDevicePixels="True">
<TextBlock Text="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}" VerticalAlignment="Center" HorizontalAlignment="Center"/>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="border" Property="Background" Value="#2f96b4"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter TargetName="border" Property="Background" Value="#2a89a4"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<vlc:VideoView Name="video" >
</vlc:VideoView>
</Grid>
</Window>
cs:
using LibVLCSharp.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace RambleWPF
{
/// <summary>
/// 视频控件3.xaml 的交互逻辑
/// </summary>
public partial class 视频控件3 : Window
{
readonly LibVLC _libvlc;
public 视频控件3()
{
InitializeComponent();
_libvlc = new LibVLC();
this.WindowStyle = WindowStyle.None;
ResizeMode = ResizeMode.NoResize;
AllowsTransparency = true;
//工作区域就是不包括任务栏的其他区域
double x = SystemParameters.WorkArea.Width;
//得到屏幕工作区域宽度
double y = SystemParameters.WorkArea.Height;
win.Width = x;
win.Height = y;
win.Top = 0;
win.Left = 0;
video.Width = x;
video.Height = y;
}
private void Window_ContentRendered(object sender, EventArgs e)
{
string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
video.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
video.MediaPlayer.Play(media);
}
}
}
}
此时启动程序,如果不出意外,将看到如下的存在“间隙”的画面:
可以看到虽然在初始化的时候我们显示指定了video控件的宽高等于窗体的宽高,但是由于rtsp视频源的画面宽高比和窗体的宽高比不一致,所以出现了“间隙”。要如何解决此问题呢?只需要在Window_ContentRendered中主动设置video.MediaPlayer的宽高比为video控件的宽高即可。
修改后的 Window_ContentRendered 是这样的:
private void Window_ContentRendered(object sender, EventArgs e)
{
string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
video.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
video.MediaPlayer.Play(media);
}
player.AspectRatio = video.Width + ":" + video.Height;
}
修改后的画面是这样的:
- 可以看到间隙已经没有了,画面按照预期的方式显示了。
拉伸问题
环境:Windows11,屏幕分辨率为2560*1440,未设置缩放
通过对全屏问题的分析,拉伸问题其实就很好理解了,只需要设置特定的宽高比即可实现,如下代码将对画面纵向和横向进行拉伸
/// <summary>
/// 挤压和拉伸
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void extrusion_Click(object sender, RoutedEventArgs e)
{
video.MediaPlayer.AspectRatio = this.Width + ":" + 100;
//video.MediaPlayer.AspectRatio = 100 + ":" + video.Height;
}
响应鼠标点击事件
由于空域问题的存在,视频画面是无法响应鼠标点击事件的,不过有一个曲线救国的办法:
- 首先设置videoView控件的 isEnable 属性为false
- 然后在视频画面上面放一个遮罩层,遮罩层背景需要设置为透明,此时点击画面将可以获取到响应的事件
核心代码如下:
初始化VideoView:
private void Window_ContentRendered(object sender, EventArgs e)
{
video.IsEnabled = false;
string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
video.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
video.MediaPlayer.Play(media);
}
player.AspectRatio = video.Width + ":" + video.Height;
}
遮罩层xaml:
<Grid x:Name="root_grid" MouseLeftButtonDown="root_grid_MouseLeftButtonDown" >
<vlc:VideoView Name="video" MouseLeftButtonDown="video_MouseLeftButtonDown">
</vlc:VideoView>
<Canvas x:Name="mask" Background="Transparent" MouseLeftButtonDown="mask_MouseLeftButtonDown"></Canvas>
</Grid>
其中,mask_MouseLeftButtonDown 和root_grid_MouseLeftButtonDown 事件可以正常响应。
而video_MouseLeftButtonDown 事件无法响应,因为空域的存在,此事件要么绑定在ForegroudWindow上面,要么可能就没有成功被委托。
播放其他类型
如下代码演示了播放M3U8和本地文件:
private void Window_ContentRendered(object sender, EventArgs e)
{
video.IsEnabled = false;
//rtsp 播放串
//string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
//m3u8播放串
//string url = "http://1257120875.vod2.myqcloud.com/0ef121cdvodtransgzp1257120875/3055695e5285890780828799271/v.f230.m3u8";
//播放文件
string url = "C:\\Users\\cml\\Desktop\\temp\\流浪地球2.mp4";
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
video.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
video.MediaPlayer.Play(media);
}
player.AspectRatio = video.Width + ":" + video.Height;
}
多视频重叠
在一个窗体中播放两个视频,一个在后,全屏显示,一个在前,小窗播放。并且点击按钮可以切换画面位置。效果如下:
实现思路:
- 首先,其实只要在xaml中编排好VideoView控件的上下位置就可以实现重叠了 ,越靠上的控件会覆盖在靠下的控件上方。
- 切换功能的实现需要分别销毁前后两个VideoView的MediaPlayer.Media对象,并重新创建。
代码如下:
xaml:
<Window x:Class="RambleWPF.视频控件2"
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:RambleWPF"
xmlns:vlc="clr-namespace:LibVLCSharp.WPF;assembly=LibVLCSharp.WPF"
mc:Ignorable="d"
Title="视频控件2" Height="450" Width="800"
Name="win"
Loaded="Window_Loaded" ContentRendered="Window_ContentRendered"
>
<Canvas>
<vlc:VideoView Name="small_video" ></vlc:VideoView>
<vlc:VideoView Name="main_video" >
<Button x:Name="switch" Content="切换" Width="80" Height="60" Canvas.Left="50" Click="switch_Click"></Button>
</vlc:VideoView>
</Canvas>
</Window>
cs:
using LibVLCSharp.Shared;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Policy;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace RambleWPF
{
/// <summary>
/// 视频控件2.xaml 的交互逻辑
/// </summary>
public partial class 视频控件2 : Window
{
readonly LibVLC _libvlc;
public 视频控件2()
{
InitializeComponent();
_libvlc = new LibVLC();
WindowStyle = WindowStyle.None;
ResizeMode = ResizeMode.NoResize;
AllowsTransparency = true;
//工作区域就是不包括任务栏的其他区域
double x = SystemParameters.WorkArea.Width;
//得到屏幕工作区域宽度
double y = SystemParameters.WorkArea.Height;
win.Width = x;
win.Height = y;
win.Top = 0;
win.Left = 0;
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
Canvas.SetLeft(main_video, 100);
Canvas.SetZIndex(main_video, 1);
main_video.Width = 1366;
main_video.Height = 768;
Canvas.SetLeft(small_video, 150);
Canvas.SetTop(small_video, 500);
Canvas.SetZIndex(small_video, 2);
small_video.Width = 300;
small_video.Height = 168.75;
}
private void Window_ContentRendered(object sender, EventArgs e)
{
this.Tag = main_video.Name;
string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
LibVLCSharp.Shared.MediaPlayer player = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
main_video.MediaPlayer = player;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
main_video.MediaPlayer.Play(media);
}
string url2 = "rtsp://xxx:xxx@192.168.1.142:554/Streaming/Channels/1";
LibVLCSharp.Shared.MediaPlayer player2 = new LibVLCSharp.Shared.MediaPlayer(_libvlc);
small_video.MediaPlayer = player2;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url2)))
{
small_video.MediaPlayer.Play(media);
}
}
private void switch_Click(object sender, RoutedEventArgs e)
{
string url = "rtsp://xxx:xxx@192.168.1.120:554/ch1/main/av_stream";
string url2 = "rtsp://xxx:xxx@192.168.1.142:554/Streaming/Channels/1";
if (this.Tag as string != main_video.Name)
{
this.Tag = main_video.Name;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
main_video.MediaPlayer.Play(media);
}
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url2)))
{
small_video.MediaPlayer.Play(media);
}
}
else
{
this.Tag = small_video.Name;
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url2)))
{
main_video.MediaPlayer.Play(media);
}
using (LibVLCSharp.Shared.Media media = new Media(_libvlc, new Uri(url)))
{
small_video.MediaPlayer.Play(media);
}
}
}
}
}
- small_video显示在前,为小屏;main_video显示在后,全屏显示
画中画
画中画本质上还是视频的重叠,可以参考视频重叠的实现思路实现。
引用
- VideoLAN.LibVLC.Windows的nuget:https://www.nuget.org/packages/VideoLAN.LibVLC.Windows/3.0.17.4
- LibVLCSharp官网:https://code.videolan.org/videolan/LibVLCSharp