Getting length of video

问题:

I am having trouble finding a simple example of how to get the video length of a file programmatically. Many people say, oh use this library/wrapper or whatever, but do not say how. I have downloaded ffmpeg, but have no clue how to actually use it and there does not seem to be any example of how to use it to get the video duration. I see how you can use it to convert videos, but I simply just want to know the duration of a video. All of the other information does not matter.

Is there any way of doing this simply, whether it be in C#, python, java, whatever, that will just return a string that indicates the length of a video file.

Please provide examples if possible. Thanks in advance!

Assume standard file formats, such as wmv, avi, mp4, mpeg. Stuff that has metadata.

回答1:

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;

回答2:

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()

回答3:

you can get all sorts of information about many types of video formats including their duration with ffmpeg by using the -i flag:

ffmpeg -i videofile.whatever

If you want a nice library that can wrap ffmpef for you in C# then you can use MediaHandlerPro

回答4:

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.

回答5:

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);
}

回答6:

I recently found a solution to a similar problem I had, with ColdFusion and FFMpeg's little cousin, FFProbe...

Is there a way to obtain the duration of a video file using ColdFusion?

FFProbe has a show_streams argument that pushes out a considerable amount of information in the initial stream within the returned output; including the width, height and duration of a video...

Not sure about C#'s syntax for running the equivalent of "ffprobe.exe -show_streams testFile" but I'm sure once you've figured that out, you can parse out the information you need from the output you receive.

回答7:

ffprobe is companian tool from the ffmpeg project. Besides provinding information from a wide range of file formats, it can also ouput in a JSON format to ease the parsing.

Check this answer for an example of a JSON output.