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.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.ProcessSt