c#提取视频缩略图问题
想做个东西，主要就是想提取视频文件的缩略图，使其显示在网页上，分不多望见谅
[解决办法]
ffmepg
[解决办法]
我把项目中用的ffmepg的类给你吧。。自己看
using System;using System.Collections.Generic;using System.Text;using System.ComponentModel;using System.Runtime.CompilerServices;using System.IO;using System.Web;namespace AUV5.Common{ public class FormatConverter { //FFmpeg配置信息 private string ffmpegpath = "/FFmpeg/ffmpeg.exe";//FFmpeg的服务器路径 private string imgsize = "400*300"; //视频截图大小 private string videosize = "480*360"; //视频大小 #region 也可将信息添加到配置文件中 //public static string ffmpegpath = ConfigurationManager.AppSettings["ffmpeg"]; //public static string imgsize = ConfigurationManager.AppSettings["imgsize"]; //public static string videosize = ConfigurationManager.AppSettings["videoize"]; #endregion private string destVideo = ""; /// <summary> /// 视频路径 /// </summary> public string DestVideo { get { return destVideo; } set { destVideo = value; } } private string destImage = ""; /// <summary> /// 图片路径 /// </summary> public string DestImage { get { return destImage; } set { destImage = value; } } /// <summary> /// 视频长度 /// </summary> public string VideoLength { get; set; } //文件类型 public enum VideoType { [Description(".avi")] AVI, [Description(".mov")] MOV, [Description(".mpg")] MPG, [Description(".mp4")] MP4, [Description(".flv")] FLV } /// <summary> /// 返回枚举类型的描述信息 /// </summary> /// <param name="myEnum"></param> /// <returns></returns> private string GetDiscription(System.Enum myEnum) { System.Reflection.FieldInfo fieldInfo = myEnum.GetType().GetField(myEnum.ToString()); object[] attrs = fieldInfo.GetCustomAttributes(typeof(DescriptionAttribute), true); if (attrs != null && attrs.Length > 0) { DescriptionAttribute desc = attrs[0] as DescriptionAttribute; if (desc != null) { return desc.Description.ToLower(); } } return myEnum.ToString(); } //将GetDesCription定义为扩展方法,需.net3.5 //public static string Description(this Enum myEnum) //{ // return GetDiscription(myEnum); //} //构造函数 //创建目录 public FormatConverter() { } #region 使用FFmpeg进行格式转换 /// <summary> /// 运行格式转换 /// </summary> /// <param name="sourceFile">要转换文件绝对路径</param> /// <param name="destPath">转换结果存储的相对路径</param> /// <param name="videotype">要转换成的文件类型</param> /// <param name="createImage">是否生成截图</param> /// <returns> /// 执行成功返回空，否则返回错误信息 /// </returns> public string Convert(string sourceFile, string destPath,string uniquename, VideoType videotype, bool createImage,bool getDuration) { //取得ffmpeg.exe的物理路径 string ffmpeg = System.Web.HttpContext.Current.Server.MapPath(ffmpegpath); if (!File.Exists(ffmpeg)) { return "找不到格式转换程序！"; } if (!File.Exists(sourceFile)) { return "找不到源文件！"; } //string uniquename = FileHelper.GetUniqueFileName(); string filename = uniquename + GetDiscription(videotype); string destFile = HttpContext.Current.Server.MapPath(destPath + filename); //if (Path.GetExtension(sourceFile).ToLower() != GetDiscription(videotype).ToLower()) //{ System.Diagnostics.ProcessStartInfo FilestartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg); FilestartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; /*ffmpeg参数说明 * -i 1.avi 输入文件 * -ab/-ac <比特率> 设定声音比特率，前面-ac设为立体声时要以一半比特率来设置，比如192kbps的就设成96，转换 均默认比特率都较小，要听到较高品质声音的话建议设到160kbps（80）以上 * -ar <采样率> 设定声音采样率，PSP只认24000 * -b <比特率> 指定压缩比特率，似乎ffmpeg是自动VBR的，指定了就大概是平均比特率，比如768，1500这样的 --加了以后转换不正常 * -r 29.97 桢速率（可以改，确认非标准桢率会导致音画不同步，所以只能设定为15或者29.97） * s 320x240 指定分辨率 * 最后的路径为目标文件 */ FilestartInfo.Arguments = " -i " + sourceFile + " -ab 80 -ar 22050 -r 29.97 -s " + videosize + " " + destFile; //FilestartInfo.Arguments = "-y -i " + sourceFile + " -s 320x240 -vcodec h264 -qscale 4 -ar 24000 -f psp -muxvb 768 " + destFile; try { //转换 System.Diagnostics.Process.Start(FilestartInfo); destVideo = destPath + filename; } catch { return "格式转换失败！"; } //} //格式不需要转换则直接复制文件到目录 //else //{ // File.Copy(sourceFile, destFile,true); // destVideo = destPath + filename; //} //提取视频长度 if (getDuration) { VideoLength = GetVideoDuration(ffmpeg, sourceFile); } //提取图片 if (createImage) { //定义进程 System.Diagnostics.ProcessStartInfo ImgstartInfo = new System.Diagnostics.ProcessStartInfo(ffmpeg); //截大图 string imgpath = destPath + uniquename + ".jpg";// FileHelper.GetUniqueFileName(".jpg"); ConvertImage(sourceFile, imgpath, imgsize, ImgstartInfo); //截小图 imgpath = destPath + uniquename + "_thumb.jpg"; DestImage = ConvertImage(sourceFile, imgpath, "80*80", ImgstartInfo); } return ""; } private string ConvertImage(string sourceFile, string imgpath, string imgsize, System.Diagnostics.ProcessStartInfo ImgstartInfo) { ImgstartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; /*参数设置 * -y（覆盖输出文件，即如果生成的文件（flv_img）已经存在的话，不经提示就覆盖掉了） * -i 1.avi 输入文件 * -f image2 指定输出格式 * -ss 8 后跟的单位为秒，从指定时间点开始转换任务 * -vframes * -s 指定分辨率 */ //duration: 00:00:00.00 string[] time = VideoLength.Split(':'); int seconds = int.Parse(time[0]) * 60 * 60 + int.Parse(time[1]) * 60 + int.Parse(time[2]); int ss = seconds > 5 ? 5 : seconds - 1; ImgstartInfo.Arguments = " -i " + sourceFile + " -y -f image2 -ss " + ss.ToString() + " -vframes 1 -s " + imgsize + " " + HttpContext.Current.Server.MapPath(imgpath); try { System.Diagnostics.Process.Start(ImgstartInfo); return imgpath; } catch { return ""; } } private string GetVideoDuration(string ffmpegfile, string sourceFile) { using (System.Diagnostics.Process ffmpeg = new System.Diagnostics.Process()) { String duration; // soon will hold our video's duration in the form "HH:MM:SS.UU" String result; // temp variable holding a string representation of our video's duration StreamReader errorreader; // StringWriter to hold output from ffmpeg // we want to execute the process without opening a shell ffmpeg.StartInfo.UseShellExecute = false; //ffmpeg.StartInfo.ErrorDialog = false; ffmpeg.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; // redirect StandardError so we can parse it // for some reason the output comes through over StandardError ffmpeg.StartInfo.RedirectStandardError = true; // set the file name of our process, including the full path // (as well as quotes, as if you were calling it from the command-line) ffmpeg.StartInfo.FileName = ffmpegfile; // set the command-line arguments of our process, including full paths of any files // (as well as quotes, as if you were passing these arguments on the command-line) ffmpeg.StartInfo.Arguments = "-i " + sourceFile; // start the process ffmpeg.Start(); // now that the process is started, we can redirect output to the StreamReader we defined errorreader = ffmpeg.StandardError; // wait until ffmpeg comes back ffmpeg.WaitForExit(); // read the output from ffmpeg, which for some reason is found in Process.StandardError result = errorreader.ReadToEnd(); // a little convoluded, this string manipulation... // working from the inside out, it: // takes a substring of result, starting from the end of the "Duration: " label contained within, // (execute "ffmpeg.exe -i somevideofile" on the command-line to verify for yourself that it is there) // and going the full length of the timestamp duration = result.Substring(result.IndexOf("Duration: ") + ("Duration: ").Length, ("00:00:00").Length); return duration; } } #endregion }}