vlc的应用之三：动态调用vlc-0.9.4的libvlc.dll

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    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.

本文出自 “Jeremiah的程序乐园” 博客，请务必保留此出处http://jeremiah.blog.51cto.com/539865/116981

本文出自 51CTO.COM技术博客

附件下载：
　　Marx_libvlc_wrapper(2).zip
　　MyOwnPlayer.rar