Getting length of video

I have tried to get the video length in a bit different way :
Actually using Windows Media Player Component also, we can get the duration of the video.
Following code snippet may help you guys :

using WMPLib;
// ...
var player = new WindowsMediaPlayer();
var clip = player.newMedia(filePath);
Console.WriteLine(TimeSpan.FromSeconds(clip.duration));

and don't forget to add the reference of wmp.dll which will be present in System32 folder.

The open-source tool MediaInfo provides comprehensive meta-data for media files and can be used easily from your own application in DLL form:

void* Hande=MediaInfo::OpenQuick("**FILENAME**", "**VERSION**;**APP_NAME**;**APP_VERSION**")
MediaInfo::Inform()

The easist and flawless solution I found is to use MediaToolkit nuget package.

using MediaToolkit;

// a method to get Width, Height, and Duration in Ticks for video.
public static Tuple<int, int, long> GetVideoInfo(string fileName)
{
    var inputFile = new MediaToolkit.Model.MediaFile { Filename = fileName };
    using (var engine = new Engine())
    {
        engine.GetMetadata(inputFile);
    }

    // FrameSize is returned as '1280x768' string.
    var size = inputFile.Metadata.VideoData.FrameSize.Split(new[] { 'x' }).Select(o => int.Parse(o)).ToArray();

    return new Tuple<int, int, long>(size[0], size[1], inputFile.Metadata.Duration.Ticks);
}

Here is an example:

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;