异步从ffmpeg输出流

Question

I created a method to call ffmpeg binaries and do stuff for me. It worked perfectly fine on a standard console application. I am trying to make a Windows Form Application version but there are few problems. The app freezes (but the progress bar is still updating) when the ffmpeg process is still running. The textboxes are not being updated. I cannot move the app window. I suspect this is because of the loop and I googled some stuff and found out that I might need to do this asynchronously but how do I do that exactly.

public void ffmpeg(string ffmpeg_exe, string args)
        {
            Process p = new Process();
            p.StartInfo.FileName = ffmpeg_exe;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.CreateNoWindow = true;
            p.StartInfo.Arguments = args;
            p.StartInfo.UseShellExecute = false;
            p.Start();

            StreamReader reader = p.StandardError;
            string line;

            string size = "", current_duration = "", duration = "";

            while ((line = reader.ReadLine()) != null)
            {
                if (!string.IsNullOrEmpty(line))
                {
                    if (line.Contains("Duration") && line.Contains("bitrate") && line.Contains("start"))
                    {
                        duration = RemoveWhitespace(Between(line, "Duration:", ", start"));
                        totaltime.Text = duration;
                    }

                    if (line.Contains("frame=") && line.Contains("size=") && line.Contains("time="))
                    {
                        size = RemoveWhitespace(Between(line, "size=", " time"));
                        current_duration = RemoveWhitespace(Between(line, "time=", " bitrate"));
                        progressBar_main.Value = Convert.ToInt32(Math.Round(TimeSpan.Parse(current_duration.Substring(0, current_duration.Length -3)).TotalSeconds * 100 / TimeSpan.Parse(duration.Substring(0,duration.Length-3)).TotalSeconds, 3));
                        current_time.Text = current_duration;
                        filesize.Text = size;
                    }
                }
            }

            p.Close();

            current_time.Text = "";
            filesize.Text = "";
            totaltime.Text = "";
            progressBar_main.Value = 0;

        }

Answer 1

Try using Task like this :

Action action = () =>
                            {
                               //Do your streaming here
                            };

Then start it :

Task t2 = Task.Factory.StartNew(action);

Hope this was useful.