[Mono-osx] OutputDataReceived event not raised when using the Process class together with Ffmpeg?

johot johan.otterud at gmail.com
Mon Jun 4 20:16:42 UTC 2012

I am trying to create a simple video converter that uses ffmpeg (console
application). To do this I am using the Process class hooking up the
OutputDataReceived event to get the output from the program.

The problem is that the event is never raised. I saw that there was a bug
about this before 2.4 but now in 2.10 the problem still exists for me. Could
the reason be that ffmpeg spawns multiple threads or something? This same
code works great in Windows:

	public void Start ()
			if (File.Exists (_outputFileName)) {
				File.Delete (_outputFileName);	
			// Set up the process
			movieEncoderProcess = new Process ();

			string ffmpegPath = "usr/local/bin/ffmpeg";

			movieEncoderProcess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
			movieEncoderProcess.StartInfo.UseShellExecute = false;
			movieEncoderProcess.StartInfo.FileName = ffmpegPath;

			movieEncoderProcess.EnableRaisingEvents = true;
			movieEncoderProcess.StartInfo.RedirectStandardOutput = true;
			movieEncoderProcess.StartInfo.Arguments = _argument;

			movieEncoderProcess.OutputDataReceived += HandleOutputDataReceived;	
			movieEncoderProcess.Exited += new EventHandler

			movieEncoderProcess.Start ();
			movieEncoderProcess.BeginOutputReadLine ();

		void HandleOutputDataReceived (object sender, DataReceivedEventArgs e)
			// Only returns null when the process is finished
			Console.WriteLine("Output is: " + e.Data);

View this message in context: http://mono.1490590.n4.nabble.com/OutputDataReceived-event-not-raised-when-using-the-Process-class-together-with-Ffmpeg-tp4649705.html
Sent from the Mono - OSX mailing list archive at Nabble.com.

More information about the Mono-osx mailing list