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  • vlc的应用之三:动态调用vlc0.9.4的libvlc.dll


    vlc-0.9.4提供的libvlc.dll是可以动态调用的,Jeremiah这一篇博客就介绍下如何用C#和WinForm框架调用libvlc.dll作个简易播放器。
     
        1. vs2005新建工程,将vlc-0.9.4的libvlc.dll,libvlccore.dll,plugins目录全部拷贝到工程目录下面\bin\Debug中。
     
        2. 创建异常结构体
    using System; 
    using System.Collections.Generic; 
    using System.Text; 
     
    namespace MyOwnPlayer 

            //异常结构体 
            public struct ExceptionStruct 
            { 
                    private int raised; 
                    private int code; 
                    private string message; 
            } 
     
            class MediaException 
            { 
            } 
    }
     
        3. CoreHandle和Core类
     using System; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class CoreHandle : SafeHandle 
            { 
                    //构造方法 
                    public CoreHandle() 
                            : base(IntPtr.Zero, true) 
                    { 
                    } 
     
                    //重写的方法 
                    public override bool IsInvalid 
                    { 
                            get { return handle == IntPtr.Zero; } 
                    } 
     
                    protected override bool ReleaseHandle() 
                    { 
                            if (!IsInvalid) 
                            { 
                                    libvlc_release(this); 
                                    handle = IntPtr.Zero; 
                            } 
                            return true; 
                    } 
     
                    protected override void Dispose(bool disposing) 
                    { 
                            ReleaseHandle(); 
                            base.Dispose(disposing); 
                    } 
     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern void libvlc_release(CoreHandle coreHandle); 
            } 

     
    using System; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class Core 
            { 
                    //coreHandle字段和属性 
                    private CoreHandle coreHandle; 
                    public CoreHandle CoreHandle 
                    { 
                            get { return coreHandle; } 
                    } 
                     
                    //构造方法 
                    public Core(string[] argv, ref ExceptionStruct ex) 
                    { 
                            coreHandle = libvlc_new(argv.Length, argv, ref ex); 
                    } 
     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern CoreHandle libvlc_new(int argc, string[] args, ref ExceptionStruct ex);
            } 

     
        3. MediaHandle和Media类,注意里面的非英文路径处理方法。
    using System; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class MediaHandle : SafeHandle 
            { 
                    //构造方法 
                    public MediaHandle() 
                            : base(IntPtr.Zero, true) 
                    { 
                    } 
     
                    //重写的方法 
                    public override bool IsInvalid 
                    { 
                            get { return handle == IntPtr.Zero; } 
                    } 
     
                    protected override bool ReleaseHandle() 
                    { 
                            if (!IsInvalid) 
                            { 
                                    libvlc_media_release(this); 
                                    handle = IntPtr.Zero; 
                            } 
                            return true; 
                    } 
     
                    protected override void Dispose(bool disposing) 
                    { 
                            ReleaseHandle(); 
                            base.Dispose(disposing); 
                    } 
     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern void libvlc_media_release(MediaHandle mediaHandle);                 
            } 

     
    using System; 
    using System.Text; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class Media 
            { 
                    //mediaHandle字段和属性 
                    private MediaHandle mediaHandle; 
                    public MediaHandle MediaHandle 
                    { 
                            get { return mediaHandle; } 
                    } 
     
                    //构造方法                
                    public Media(CoreHandle coreHandle, String filename, ref ExceptionStruct ex) 
                    { 
                            //c#为UTF-16编码, libvlc.dll为UTF-8编码, 需要转换. 
                            UTF8Encoding utf8 = new UTF8Encoding(); 
                            mediaHandle = libvlc_media_new(coreHandle, utf8.GetBytes(filename), ref ex); 
                    } 
                     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern MediaHandle libvlc_media_new 
                            (CoreHandle coreHandle, [MarshalAs(UnmanagedType.LPArray)] byte[] link, ref ExceptionStruct ex); 
                    } 

     
        5. MediaPlayerHandle和MediaPlayer类
     using System; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class MediaPlayerHandle : SafeHandle 
            { 
                    //构造方法 
                    public MediaPlayerHandle() 
                            : base(IntPtr.Zero, true) 
                    { 
                    } 
     
                    //重写的方法 
                    public override bool IsInvalid 
                    { 
                            get { return handle == IntPtr.Zero; } 
                    } 
     
                    protected override bool ReleaseHandle() 
                    { 
                            if (!IsInvalid) 
                            { 
                                    libvlc_media_player_release(this);                                handle = IntPtr.Zero; 
                            } 
                            return true; 
                    } 
     
                    protected override void Dispose(bool disposing) 
                    { 
                            ReleaseHandle(); 
                            base.Dispose(disposing); 
                    } 
     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern void libvlc_media_player_release(MediaPlayerHandle mediaPlayerHandle); 
            } 

     
     using System; 
    using System.Runtime.InteropServices; 
     
    namespace MyOwnPlayer 

            class MediaPlayer 
            { 
                    //mediaPlayerHandle字段和属性 
                    private MediaPlayerHandle mediaPlayerHandle; 
                    public MediaPlayerHandle MediaPlayerHandle 
                    { 
                            get { return mediaPlayerHandle; } 
                    } 
     
                    //构造方法 
                    public MediaPlayer(MediaHandle mediaHandle, ref ExceptionStruct ex) 
                    { 
                            mediaPlayerHandle = libvlc_media_player_new_from_media(mediaHandle, ref ex); 
                    } 
     
                    //设置父窗口 
                    public void VedioSetParent(CoreHandle coreHandle, IntPtr hDT, ref ExceptionStruct ex) 
                    { 
                            libvlc_video_set_parent(coreHandle, hDT, ref ex); 
                    } 
     
                    //播放 
                    public void Play(ref ExceptionStruct ex) 
                    { 
                            libvlc_media_player_play(mediaPlayerHandle, ref ex); 
                    } 
     
                    //停止 
                    public void Stop(ref ExceptionStruct ex) 
                    { 
                            libvlc_media_player_stop(mediaPlayerHandle, ref ex); 
                    } 
     
                    //Dll动态导入 
                    [DllImport("libvlc")] 
                    private static extern MediaPlayerHandle libvlc_media_player_new_from_media(MediaHandle libvlc_media_handle, ref ExceptionStruct ex); 
     
                    [DllImport("libvlc")] 
                    private static extern void libvlc_video_set_parent(CoreHandle coreHandle, IntPtr hDT, ref ExceptionStruct ex); 
     
                    [DllImport("libvlc")] 
                    private static extern void libvlc_media_player_play(MediaPlayerHandle mediaPlayerHandle, ref ExceptionStruct ex); 
     
                    [DllImport("libvlc")] 
                    private static extern void libvlc_media_player_stop(MediaPlayerHandle mediaPlayerHandle, ref ExceptionStruct ex); 
            } 

     
        6. 基本工作做好了。下一步建立一个Form,里面画一个Panel(播放容器),画一个Textbox(播放地址),画一个Button(播放按钮),Button的点击事件为:
     private void button1_Click(object sender, EventArgs e) 

            //要播放的文件的uri 
            string uri = this.textBox1.Text; 

             //进行播放的控件的句柄 
            IntPtr hdl = this.panel1.Handle; 

             //播放参数 
            string[] argv = new string[] { "-I", "--ignore-config" }; 

             //vlc对象的创建 
            ExceptionStruct ex = new ExceptionStruct(); 
            Core core = new Core(argv, ref ex); 
            Media media = new Media(core.CoreHandle, uri, ref ex); 
            MediaPlayer player = new MediaPlayer(media.MediaHandle, ref ex); 

             //垃圾回收 
            GC.Collect(); 

             //播放 
            player.VedioSetParent(core.CoreHandle, hdl, ref ex); 
            player.Play(ref ex); 

             //继续回收垃圾等相关操作 
            GC.Collect(); 
            GC.WaitForPendingFinalizers(); 
    }
     
        7. 基本的播放功能就是这样实现的。其他接口请参考源码下面的\include\vlc\libvlc.h文件,里面有比较详细的对外接口的说明。
     
        8. 以上代码已经发送到附件中(MyOwnPlayer.rar),参考网址的楼主写的代码也在附件中(Marx_libvlc_wrapper(2).zip)。调试附件请注意第1步。
       
    参考网址:
    1. http://forum.videolan.org/viewtopic.php?f=14&t=47385&st=0&sk=t&sd=a&hilit=C%23+wrapper
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  • 原文地址:https://www.cnblogs.com/qq78292959/p/2076993.html
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