Question

I have a app that is doing some video processing.

I need to analyze the media before processing it.

The ffmpeg utility ffprobe.exe provides all the information I need.

However the code I am using will not return the text that appears when the command is ran in a cmd window :

public static string RunConsoleCommand(string command, string args)
{
    var consoleOut = "";

    using (var process = new Process())
    {
        process.StartInfo = new ProcessStartInfo
        {
            FileName = command,
            Arguments = args,
            UseShellExecute = false,
            CreateNoWindow = true,
            RedirectStandardOutput = true
        };

        process.Start();
        consoleOut = process.StandardOutput.ReadToEnd();
        process.WaitForExit();

        return consoleOut;
    }
}

Any Ideas?

Answer 1

The Process class has some events to handle that :

public static string RunConsoleCommand(string command, string args)
{
    var consoleOut = "";

    using (var process = new Process())
    {
        process.StartInfo = new ProcessStartInfo
        {
            FileName = command,
            Arguments = args,
            UseShellExecute = false,
            CreateNoWindow = true,
            RedirectStandardOutput = true
        };

        // Register for event and do whatever
        process.OutputDataReceived += new DataReceivedEventHandler((snd, e) => { consoleOut += e.Data; });

        process.Start();
        process.WaitForExit();

        return consoleOut;
    }
}

You also have ErrorDataReceived, which works the same way.

I’m using these events in some projects, and it works like a charm. Hope that helps.

EDIT : Fixed the code, you need to attach the handlers before you start the process.