So I'm using the code below to convert a specified file, by running ffmpeg, and I need the progress to be visible in a progressbar, so I#d need to get it to display the cmd output to my textbox in realtime and from there get it to being displayed by the progressbar, any help?
 private void convertbutton_Click(object sender, RoutedEventArgs e)
    {
        string resdir = AppDomain.CurrentDomain.BaseDirectory + "\\res";
        Extract("ADC", AppDomain.CurrentDomain.BaseDirectory + "\\res", "res", "ffmpeg.exe");
        string ffdir = AppDomain.CurrentDomain.BaseDirectory + "\\res\\ffmpeg.exe";
        string arg =  @"-y -activation_bytes ";
        string arg1 = @" -i ";
        string arg2 = @" -ab 80k -vn ";
        string abytes = bytebox.Text;
        string arguments = arg + abytes + arg1 + openFileDialog1.FileName + arg2 + saveFileDialog1.FileName;
        Process ffm = new Process();
        ffm.StartInfo.FileName = ffdir;
        ffm.StartInfo.Arguments = arguments;
        ffm.StartInfo.CreateNoWindow = true;
        ffm.StartInfo.RedirectStandardOutput = true;
        ffm.StartInfo.RedirectStandardError = true;
        ffm.StartInfo.UseShellExecute = false;
        ffm.StartInfo.WorkingDirectory = Directory.GetCurrentDirectory();
        ffm.Start();
        ffm.WaitForExit();
        ffm.Close();
        Directory.Delete(resdir, true);
    }
FFMPEG Output regulary looks like this:
size=    4824kB time=00:08:13.63 bitrate=  80.1kbits/s speed=  33x