本人之前很多的文章中均提到了使用libvlc为播放器内核制作的播放器,也许有些朋友对此感兴趣,于是我用c#写了一个调用libvlc api实现的万能视频播放器,与大家分享一下。说它“万能”,当然是因为我们站在了vlc的肩膀上。
vlc是一个强大而且开源的多媒体播放器,也可以说是一个多媒体平台。它支持非常广泛的媒体格式的本地播放,完全可以媲美mplayer,其对视频网络流的处理能力更是非常强悍。libvlc就是指的vlc的核心,它向外提供了一系列的接口,通过接口,来实现视频播放等复杂的功能。libvlc对外提供了c语言的接口,也有其他语言,包括.net的绑定,在其官网上就有,不过已经“年久失修”。我之前用Qt, MFC实现过基于libvlc的播放器,不过鉴于园子里c#开发人员较多,遂用c#封装了一下libvlc的API接口,并实现了一个视频播放器。
先上鉴赏图,外表很简单,不过,外表不是重点:)
首先是libvlc的一些导出函数,我在注释里对它们的功能都有说明
1 // 创建一个libvlc实例,它是引用计数的 2 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 3 [SuppressUnmanagedCodeSecurity] 4 private static extern IntPtr libvlc_new(int argc, IntPtr argv); 5 6 // 释放libvlc实例 7 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 8 [SuppressUnmanagedCodeSecurity] 9 public static extern void libvlc_release(IntPtr libvlc_instance); 10 11 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 12 [SuppressUnmanagedCodeSecurity] 13 public static extern String libvlc_get_version(); 14 15 // 从视频来源(例如Url)构建一个libvlc_meida16 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 17 [SuppressUnmanagedCodeSecurity] 18 private static extern IntPtr libvlc_media_new_location(IntPtr libvlc_instance, IntPtr path); 19 20 // 从本地文件路径构建一个libvlc_media21 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 22 [SuppressUnmanagedCodeSecurity] 23 private static extern IntPtr libvlc_media_new_path(IntPtr libvlc_instance, IntPtr path); 24 25 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 26 [SuppressUnmanagedCodeSecurity] 27 public static extern void libvlc_media_release(IntPtr libvlc_media_inst); 28 29 // 创建libvlc_media_player(播放核心)30 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 31 [SuppressUnmanagedCodeSecurity] 32 public static extern IntPtr libvlc_media_player_new(IntPtr libvlc_instance); 33 34 // 将视频(libvlc_media)绑定到播放器上35 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 36 [SuppressUnmanagedCodeSecurity] 37 public static extern void libvlc_media_player_set_media(IntPtr libvlc_media_player, IntPtr libvlc_media); 38 39 // 设置图像输出的窗口40 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 41 [SuppressUnmanagedCodeSecurity] 42 public static extern void libvlc_media_player_set_hwnd(IntPtr libvlc_mediaplayer, Int32 drawable); 43 44 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 45 [SuppressUnmanagedCodeSecurity] 46 public static extern void libvlc_media_player_play(IntPtr libvlc_mediaplayer); 47 48 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 49 [SuppressUnmanagedCodeSecurity] 50 public static extern void libvlc_media_player_pause(IntPtr libvlc_mediaplayer); 51 52 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 53 [SuppressUnmanagedCodeSecurity] 54 public static extern void libvlc_media_player_stop(IntPtr libvlc_mediaplayer); 55 56 // 解析视频资源的媒体信息(如时长等)57 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 58 [SuppressUnmanagedCodeSecurity] 59 public static extern void libvlc_media_parse(IntPtr libvlc_media); 60 61 // 返回视频的时长(必须先调用libvlc_media_parse之后,该函数才会生效)62 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 63 [SuppressUnmanagedCodeSecurity] 64 public static extern Int64 libvlc_media_get_duration(IntPtr libvlc_media); 65 66 // 当前播放的时间67 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 68 [SuppressUnmanagedCodeSecurity] 69 public static extern Int64 libvlc_media_player_get_time(IntPtr libvlc_mediaplayer); 70 71 // 设置播放位置(拖动)72 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 73 [SuppressUnmanagedCodeSecurity] 74 public static extern void libvlc_media_player_set_time(IntPtr libvlc_mediaplayer, Int64 time); 75 76 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 77 [SuppressUnmanagedCodeSecurity] 78 public static extern void libvlc_media_player_release(IntPtr libvlc_mediaplayer); 79 80 // 获取和设置音量81 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 82 [SuppressUnmanagedCodeSecurity] 83 public static extern int libvlc_audio_get_volume(IntPtr libvlc_media_player); 84 85 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 86 [SuppressUnmanagedCodeSecurity] 87 public static extern void libvlc_audio_set_volume(IntPtr libvlc_media_player, int volume); 88 89 // 设置全屏90 [DllImport("libvlc", CallingConvention = CallingConvention.StdCall, ExactSpelling = true)] 91 [SuppressUnmanagedCodeSecurity] 92 public static extern void libvlc_set_fullscreen(IntPtr libvlc_media_player, int isFullScreen);
要使用libvlc api进行播放,首先需要创建一个libvlc的实例,就是lbvlc_instance,之后所有的操作都是基于这个实例来完成。
每一个播放窗口,对应一个libvlc_media_player,而每一个媒体文件,就是一个libvlc_media。所以,调用的步骤就是:
下面对这些操作进行封装,以供上层使用。
class VlcPlayer { private IntPtr libvlc_instance_; private IntPtr libvlc_media_player_; private double duration_; public VlcPlayer(string pluginPath) { string plugin_arg = "--plugin-path=" + pluginPath; string[] arguments = { "-I", "dummy", "--ignore-config", "--no-video-title", plugin_arg }; libvlc_instance_ = LibVlcAPI.libvlc_new(arguments); libvlc_media_player_ = LibVlcAPI.libvlc_media_player_new(libvlc_instance_); } public void SetRenderWindow(int wndHandle) { if (libvlc_instance_ != IntPtr.Zero && wndHandle != 0) { LibVlcAPI.libvlc_media_player_set_hwnd(libvlc_media_player_, wndHandle); } } public void PlayFile(string filePath) { IntPtr libvlc_media = LibVlcAPI.libvlc_media_new_path(libvlc_instance_, filePath); if (libvlc_media != IntPtr.Zero) { LibVlcAPI.libvlc_media_parse(libvlc_media); duration_ = LibVlcAPI.libvlc_media_get_duration(libvlc_media) / 1000.0; LibVlcAPI.libvlc_media_player_set_media(libvlc_media_player_, libvlc_media); LibVlcAPI.libvlc_media_release(libvlc_media); LibVlcAPI.libvlc_media_player_play(libvlc_media_player_); } } public void Pause() { if (libvlc_media_player_ != IntPtr.Zero) { LibVlcAPI.libvlc_media_player_pause(libvlc_media_player_); } } public void Stop() { if (libvlc_media_player_ != IntPtr.Zero) { LibVlcAPI.libvlc_media_player_stop(libvlc_media_player_); } } public double GetPlayTime() { return LibVlcAPI.libvlc_media_player_get_time(libvlc_media_player_) / 1000.0; } public void SetPlayTime(double seekTime) { LibVlcAPI.libvlc_media_player_set_time(libvlc_media_player_, (Int64)(seekTime * 1000)); } public int GetVolume() { return LibVlcAPI.libvlc_audio_get_volume(libvlc_media_player_); } public void SetVolume(int volume) { LibVlcAPI.libvlc_audio_set_volume(libvlc_media_player_, volume); } public void SetFullScreen(bool istrue) { LibVlcAPI.libvlc_set_fullscreen(libvlc_media_player_, istrue ? 1 : 0); } public double Duration() { return duration_; } public string Version() { return LibVlcAPI.libvlc_get_version(); } }
封装为VlcPlayer之后,调用就会变得非常简单。
程序做好之后,需要带上libvlc.dll和libvlccore.dll,这两个是vlc的播放内核,因为vlc把编解码和格式解析的支持设计成了插件的形式,所以还必须要带上vlc的plugins目录里的插件。
我把整个工程打包(包括libvlc.dll和libvlccore.dll)上传到了博客上,点击这里,就可以下载。
plugins目录文件有点大(因为libvlc支持的格式和功能非常多,如果你不需要,删掉对应插件即可),我放到了115网盘,下载地址是http://115.com/file/dnre4jg7#plugins.7z。下载后放到“bin/Debug”目录即可调试运行。
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HaibinDev软件工作室。(版权所有,转载请注明作者和出处~)
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