How to get the video duration using FFMPEG in C# asp.net

Question

I want to get the video file duration in string using C#. I searched the internet and all i get is:

ffmpeg -i inputfile.avi

And every1 say that parse the output for duration.

Here is my code which is

string filargs = "-y -i " + inputavi + " -ar 22050 " + outputflv;
    Process proc;
    proc = new Process();
    proc.StartInfo.FileName = spath;
    proc.StartInfo.Arguments = filargs;
    proc.StartInfo.UseShellExecute = false;
    proc.StartInfo.CreateNoWindow = false;
    proc.StartInfo.RedirectStandardOutput = false;
    try
    {
        proc.Start();

    }
    catch (Exception ex)
    {
        Response.Write(ex.Message);
    }

    try
    {
        proc.WaitForExit(50 * 1000);
    }
    catch (Exception ex)
    { }
    finally
    {
        proc.Close();
    }

Now please tell me how can i save the output string and parse it for the video duration.

Thanks and regards,

Answer 1

There is another Option to get Video Length ,by using Media Info DLL

Using Ffmpeg :

proc.StartInfo.RedirectErrorOutput = true;
string message = proc.ErrorOutput.ReadToEnd();

Filtering shouldn't be an issue ,so do it you're self.

PS : using ffmpeg you should not read the StandardOutput but ErrorOutput i dont know why ,but it work's only like that.

Answer 2

FFmpeg is a little bit of an adventure to parse. But in any case, here's what you need to know.

First, FFmpeg doesn't play well with RedirectOutput options

What you'll need to do is instead of launching ffmpeg directly, launch cmd.exe, passing in ffmpeg as an argument, and redirecting the output to a "monitor file" through a command line output like so... note that in the while (!proc.HasExited) loop you can read this file for real-time FFmpeg status, or just read it at the end if this is a quick operation.

        FileInfo monitorFile = new FileInfo(Path.Combine(ffMpegExe.Directory.FullName, "FFMpegMonitor_" + Guid.NewGuid().ToString() + ".txt"));

        string ffmpegpath = Environment.SystemDirectory + "\\cmd.exe"; 
        string ffmpegargs = "/C " + ffMpegExe.FullName + " " + encodeArgs + " 2>" + monitorFile.FullName;

        string fullTestCmd = ffmpegpath + " " + ffmpegargs;

        ProcessStartInfo psi = new ProcessStartInfo(ffmpegpath, ffmpegargs);
        psi.WorkingDirectory = ffMpegExe.Directory.FullName;
        psi.CreateNoWindow = true;
        psi.UseShellExecute = false;
        psi.Verb = "runas";

        var proc = Process.Start(psi);

        while (!proc.HasExited)
        {
            System.Threading.Thread.Sleep(1000);
        }

        string encodeLog = System.IO.File.ReadAllText(monitorFile.FullName);

Great, now you've got the log of what FFmpeg just spit out. Now to get the duration. The duration line will look something like this:

Duration: 00:10:53.79, start: 0.000000, bitrate: 9963 kb/s

Clean up the results into a List<string>:

var encodingLines = encodeLog.Split(System.Environment.NewLine[0]).Where(line => string.IsNullOrWhiteSpace(line) == false && string.IsNullOrEmpty(line.Trim()) == false).Select(s => s.Trim()).ToList();

... then loop through them looking for Duration.

        foreach (var line in encodingLines)
        {
            // Duration: 00:10:53.79, start: 0.000000, bitrate: 9963 kb/s
            if (line.StartsWith("Duration"))
            {
                var duration = ParseDurationLine(line);
            }
        }

Here's some code that can do the parse for you:

    private TimeSpan ParseDurationLine(string line)
    {
        var itemsOfData = line.Split(" "[0], "="[0]).Where(s => string.IsNullOrEmpty(s) == false).Select(s => s.Trim().Replace("=", string.Empty).Replace(",", string.Empty)).ToList();

        string duration = GetValueFromItemData(itemsOfData, "Duration:");

        return TimeSpan.Parse(duration);
    }

    private string GetValueFromItemData(List<string> items, string targetKey)
    {
        var key = items.FirstOrDefault(i => i.ToUpper() == targetKey.ToUpper());

        if (key == null) { return null; }
        var idx = items.IndexOf(key);

        var valueIdx = idx + 1;

        if (valueIdx >= items.Count)
        {
            return null;
        }

        return items[valueIdx];
    }

Answer 3

Just check it out::

    //Create varriables

    string ffMPEG = System.IO.Path.Combine(Application.StartupPath, "ffMPEG.exe");
    system.Diagnostics.Process mProcess = null;

    System.IO.StreamReader SROutput = null;
    string outPut = "";

    string filepath = "D:\\source.mp4";
    string param = string.Format("-i \"{0}\"", filepath);

    System.Diagnostics.ProcessStartInfo oInfo = null;

    System.Text.RegularExpressions.Regex re = null;
    System.Text.RegularExpressions.Match m = null;
    TimeSpan Duration =  null;

    //Get ready with ProcessStartInfo
    oInfo = new System.Diagnostics.ProcessStartInfo(ffMPEG, param);
    oInfo.CreateNoWindow = true;

    //ffMPEG uses StandardError for its output.
    oInfo.RedirectStandardError = true;
    oInfo.WindowStyle = ProcessWindowStyle.Hidden;
    oInfo.UseShellExecute = false;

    // Lets start the process

    mProcess = System.Diagnostics.Process.Start(oInfo);

    // Divert output
    SROutput = mProcess.StandardError;

    // Read all
    outPut = SROutput.ReadToEnd();

    // Please donot forget to call WaitForExit() after calling SROutput.ReadToEnd

    mProcess.WaitForExit();
    mProcess.Close();
    mProcess.Dispose();
    SROutput.Close();
    SROutput.Dispose();

    //get duration

    re = new System.Text.RegularExpressions.Regex("[D|d]uration:.((\\d|:|\\.)*)");
    m = re.Match(outPut);

    if (m.Success) {
        //Means the output has cantained the string "Duration"
        string temp = m.Groups(1).Value;
        string[] timepieces = temp.Split(new char[] {':', '.'});
        if (timepieces.Length == 4) {

            // Store duration
            Duration = new TimeSpan(0, Convert.ToInt16(timepieces[0]), Convert.ToInt16(timepieces[1]), Convert.ToInt16(timepieces[2]), Convert.ToInt16(timepieces[3]));
        }
    }

With thanks, Gouranga Das.