C#实现通过ffmpeg从flv视频文件中截图的方法

本文实例讲述了c#实现通过ffmpeg从flv视频文件中截图的方法。分享给大家供大家参考。具体分析如下：

需要先下载ffmpeg，这是开源的，代码如下所示：

using system;
using system.configuration;
public class publicmethod:system.web.ui.page
{
    public publicmethod()
    {
    }
    //文件路径
    public static string ffmpegtool = "ffmpeg/ffmpeg.exe";        
    public static string mencodertool = "mencoder/mencoder.exe";
    public static string flvtool = "flvtool/flvtool2.exe";//flv标记工具
    public static string upfile = "upfiles" + "/";//上传文件夹
    public static string imgfile = "imgfile" + "/";//图片文件夹
    public static string playfile = "playfiles" + "/";//flv文件夹
    public static string xmlfile = "xmlfiles" + "/";//xml文件夹
    public static string sizeofimg = "240x180";//图片的宽与高
    public static string widthoffile = "400";//flv文件的宽度
    public static string heightoffile = "350";//flv文件的高度
    //public static string ffmpegtool = configurationmanager.appsettings["ffmpeg"];
    //public static string mencodertool = configurationmanager.appsettings["mencoder"];
    //public static string upfile = configurationmanager.appsettings["upfile"] + "/";
    //public static string imgfile = configurationmanager.appsettings["imgfile"] + "/";
    //public static string playfile = configurationmanager.appsettings["playfile"] + "/";
    //文件图片大小
    //public static string sizeofimg = configurationmanager.appsettings["catchflvimgsize"];
    //文件大小
    //public static string widthoffile = configurationmanager.appsettings["widthsize"];
    //public static string heightoffile = configurationmanager.appsettings["heightsize"];
    //   // //获取文件的名字
    private system.timers.timer mytimer = new system.timers.timer(3000);//记时器
    public static string flvname = "";
    public static string imgname = "";
    public static string flvxml = "";
    public static int pid = 0;
    public static string getfilename(string filename)
    {
        int i = filename.lastindexof("\") + 1;
        string name = filename.substring(i);
        return name;
    }
    //获取文件扩展名
    public static string getextension(string filename)
    {
        int i = filename.lastindexof(".")+1;
        string name = filename.substring(i);
        return name;
    }
    //
    #region //运行ffmpeg的视频解码，(这里是绝对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是绝对路径)
    /// </summary>
    /// <param name="filename">上传视频文件的路径（原文件）</param>
    /// <param name="playfile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgfile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址;   失败:返回空字符串</returns>
    public void changefilephy(string filename, string playfile, string imgfile)
    {
        //取得ffmpeg.exe的路径,路径配置在web.config中,如:<add   key="ffmpeg"   value="e:aspx1ffmpeg.exe"   /> 
        string ffmpeg = server.mappath(publicmethod.ffmpegtool);
        if ((!system.io.file.exists(ffmpeg)) || (!system.io.file.exists(filename)))
        {
            return;
        }
        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/web/user1/00001.jpg 
        string flv_file = system.io.path.changeextension(playfile, ".flv");
        //截图的尺寸大小,配置在web.config中,如:<add   key="catchflvimgsize"   value="240x180"   /> 
        string flvimgsize = publicmethod.sizeofimg;
        system.diagnostics.processstartinfo filestartinfo = new system.diagnostics.processstartinfo(ffmpeg);
        filestartinfo.windowstyle = system.diagnostics.processwindowstyle.hidden;
        filestartinfo.arguments = " -i " + filename + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthoffile + "x" + heightoffile + " " + flv_file;
        //imgstartinfo.arguments = "   -i   " + filename + "   -y   -f   image2   -t   0.05   -s   " + flvimgsize + "   " + flv_img;
        try
        {
            //转换
            system.diagnostics.process.start(filestartinfo);
            //截图
            catchimg(filename, imgfile);
            //system.diagnostics.process.start(imgstartinfo);
        }
        catch
        {
        }
    }
    #endregion
    #region 截图
    public string catchimg(string filename,string imgfile)
    {
        //
        string ffmpeg = server.mappath(publicmethod.ffmpegtool);
        //
        string flv_img =imgfile+".jpg";
        //
        string flvimgsize = publicmethod.sizeofimg;
        //
        system.diagnostics.processstartinfo imgstartinfo = new system.diagnostics.processstartinfo(ffmpeg);
        imgstartinfo.windowstyle = system.diagnostics.processwindowstyle.hidden;
        //
        imgstartinfo.arguments = "   -i   " + filename + "  -y  -f  image2   -ss 2 -vframes 1  -s   " + flvimgsize + "   " + flv_img;
        try
        {
            system.diagnostics.process.start(imgstartinfo);
        }
        catch
        {
            return "";
        }
        //
        catchflvtool(filename);
        if (system.io.file.exists(flv_img))
        {
            return flv_img;
        }
        return "";
    }
    #endregion
    #region //运行ffmpeg的视频解码，(这里是(虚拟)相对路径)
    /// <summary>
    /// 转换文件并保存在指定文件夹下面(这里是相对路径)
    /// </summary>
    /// <param name="filename">上传视频文件的路径（原文件）</param>
    /// <param name="playfile">转换后的文件的路径（网络播放文件）</param>
    /// <param name="imgfile">从视频文件中抓取的图片路径</param>
    /// <returns>成功:返回图片虚拟地址;   失败:返回空字符串</returns>
    public void changefilevir(string filename, string playfile, string imgfile)
    {
        //取得ffmpeg.exe的路径,路径配置在web.config中,如:<add   key="ffmpeg"   value="e:\aspx1\ffmpeg.exe"   /> 
        string ffmpeg = server.mappath(publicmethod.ffmpegtool);
        if ((!system.io.file.exists(ffmpeg)) || (!system.io.file.exists(filename)))
        {
            return;
        }
        //获得图片和(.flv)文件相对路径/最后存储到数据库的路径,如:/web/user1/00001.jpg 
        string flv_img = system.io.path.changeextension(server.mappath(imgfile), ".jpg");
        string flv_file = system.io.path.changeextension(server.mappath(playfile), ".flv");
        //截图的尺寸大小,配置在web.config中,如:<add   key="catchflvimgsize"   value="240x180"   /> 
        string flvimgsize = publicmethod.sizeofimg;
        system.diagnostics.processstartinfo filestartinfo = new system.diagnostics.processstartinfo(ffmpeg);
        filestartinfo.windowstyle = system.diagnostics.processwindowstyle.hidden;
        //此处组合成ffmpeg.exe文件需要的参数即可,此处命令在ffmpeg   0.4.9调试通过
        //ffmpeg -i f:\01.wmv -ab 56 -ar 22050 -b 500 -r 15 -s 320x240 f:\test.flv
        filestartinfo.arguments = " -i " + filename + " -ab 56 -ar 22050 -b 500 -r 15 -s " + widthoffile + "x" + heightoffile + " " + flv_file;
        try
        {
            system.diagnostics.process ps = new system.diagnostics.process();
            ps.startinfo = filestartinfo;
            ps.start();
            session.add("processid", ps.id);
            session.add("flv", flv_file);
            session.add("img", imgfile);
            mytimer.elapsed += new system.timers.elapsedeventhandler(mytimer_test);
            mytimer.enabled = true;
        }
        catch
        {
        }
    }
    #endregion
    #region //运行mencoder的视频解码器转换(这里是(绝对路径))
    public void mchangefilephy(string vfilename, string playfile, string imgfile)
    {
        string tool = server.mappath(publicmethod.mencodertool);
        //string mplaytool = server.mappath(publicmethod.ffmpegtool);
        if ((!system.io.file.exists(tool)) || (!system.io.file.exists(vfilename)))
        {
            return;
        }
        string flv_file = system.io.path.changeextension(playfile, ".flv");
        //截图的尺寸大小,配置在web.config中,如:<add   key="catchflvimgsize"   value="240x180"   /> 
        string flvimgsize = publicmethod.sizeofimg;
        system.diagnostics.processstartinfo filestartinfo = new system.diagnostics.processstartinfo(tool);
        filestartinfo.windowstyle = system.diagnostics.processwindowstyle.hidden;
        filestartinfo.arguments = " " + vfilename + " -o " + flv_file + " -of lavf -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vcodec=flv:vbitrate=200:mbd=2:mv0:trell:v4mv:cbp:last_pred=1:dia=-1:cmp=0:vb_strategy=1 -vf scale=" + widthoffile + ":" +heightoffile + " -ofps 12 -srate 22050";
        try
        {
            system.diagnostics.process ps = new system.diagnostics.process();
            ps.startinfo = filestartinfo;
            ps.start();
            session.add("processid", ps.id);
            session.add("flv", flv_file);
            session.add("img", imgfile);
            //pid = ps.id;
            //flvname = flv_file;
            //imgname = imgfile;
            mytimer.elapsed += new system.timers.elapsedeventhandler(mytimer_test);
            mytimer.enabled = true;
        }
        catch
        {
        }
    }
    /// <summary>
    /// 记时器功能，自动保存截图
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void mytimer_test(object sender, system.timers.elapsedeventargs e)
    {
        if (!object.equals(null, session["processid"]))
        {
            try
            {
                system.diagnostics.process prs = system.diagnostics.process.getprocessbyid(int.parse(session["processid"].tostring()));
                if (prs.hasexited)
                {
                    catchimg(session["flv"].tostring(), session["img"].tostring());
                    catchflvtool(session["flv"].tostring());
                    mytimer.enabled = false;
                    mytimer.close();
                    mytimer.dispose();
                    session.abandon();
                }
            }
            catch
            {
                catchimg(session["flv"].tostring(), session["img"].tostring());
                catchflvtool(session["flv"].tostring());
                mytimer.enabled = false;
                mytimer.close();
                mytimer.dispose();
                session.abandon();
            }
        }
    }
    #endregion
    public string catchflvtool(string filename)
    {
        //
        string flvtools = server.mappath(publicmethod.flvtool);
        //
        string flv_xml = filename.replace(".flv", ".xml").replace(publicmethod.upfile.replace("/", ""), publicmethod.xmlfile.replace("/", ""));
        //
        system.diagnostics.processstartinfo imgstartinfo = new system.diagnostics.processstartinfo(flvtools);
        imgstartinfo.windowstyle = system.diagnostics.processwindowstyle.hidden;
        //
        imgstartinfo.arguments = "   " + filename + "   -upx   " + filename + "  >  " + flv_xml;
        try
        {
            system.diagnostics.process.start(imgstartinfo);
        }
        catch
        {
            return "";
        }
        //
        if (system.io.file.exists(flv_xml))
        {
            return flv_xml;
        }
        return "";
    }
}

希望本文所述对大家的c#程序设计有所帮助。