C# 如何知道一个影像文件能够播放多长时间

分享给你一段代码吧

   

   
   
   
   

    
    
    
    
using DirectShowLib; 
    
    
    
    
using DirectShowLib.DES; 
    
    
    
    
using System.Runtime.InteropServices; 
    
    
    
    
 
    
    
    
    
var mediaDet = (IMediaDet)new MediaDet(); 
    
    
    
    
DsError.ThrowExceptionForHR(mediaDet.put_Filename(FileName)); 
    
    
    
    
 
    
    
    
    
// find the video stream in the file 
    
    
    
    
int index; 
    
    
    
    
var type = Guid.Empty; 
    
    
    
    
for (index = 0; index < 1000 && type != MediaType.Video; index++) 
    
    
    
    
{ 
    
    
    
    
mediaDet.put_CurrentStream(index); 
    
    
    
    
mediaDet.get_StreamType(out type); 
    
    
    
    
} 
    
    
    
    
 
    
    
    
    
// retrieve some measurements from the video 
    
    
    
    
double frameRate; 
    
    
    
    
mediaDet.get_FrameRate(out frameRate); 
    
    
    
    
 
    
    
    
    
var mediaType = new AMMediaType(); 
    
    
    
    
mediaDet.get_StreamMediaType(mediaType); 
    
    
    
    
var videoInfo = (VideoInfoHeader)Marshal.PtrToStructure(mediaType.formatPtr, typeof(VideoInfoHeader)); 
    
    
    
    
DsUtils.FreeAMMediaType(mediaType); 
    
    
    
    
var width = videoInfo.BmiHeader.Width; 
    
    
    
    
var height = videoInfo.BmiHeader.Height; 
    
    
    
    
 
    
    
    
    
double mediaLength; 
    
    
    
    
mediaDet.get_StreamLength(out mediaLength); 
    
    
    
    
var frameCount = (int)(frameRate * mediaLength); 
    
    
    
    
var duration = frameCount / frameRate;
   
   
   
   

更为简单的方式是调用ffmpeg， ffmpeg -i一下，需要什么信息，解析一下输出内容就好了。