Launch VLC in Java and connect to it via rc interface

I've already seen this thread, but I'm still having an issue: starting vlc player in java It appears the Java bindings for VLC are no longer under active development and do not supp开发者_StackOverflow中文版ort everything possible on the command line anyway.

Given the following code, I can't launch VLC from a Java application on Mac OS 10.5.8 (Java 1.6) and then connect to it via the rc interface through the Terminal or another Java application.

public class Main {

public static void main(String[] args) {
    String s = null;


    try {
        //Process p = Runtime.getRuntime().exec("/Applications/VLC.app/Contents/MacOS/VLC -I telnet --telnet-host=localhost:4442 -I rc --rc-host=localhost:4444");
        //Process p = Runtime.getRuntime().exec("/Applications/VLC.app/Contents/MacOS/VLC -I rc --rc-host=localhost:4444");

        //ProcessBuilder pb = new ProcessBuilder("/Applications/VLC.app/Contents/MacOS/VLC","-I rc","--rc-host=localhost:4444");
        ProcessBuilder pb = new ProcessBuilder("/Applications/VLC.app/Contents/MacOS/VLC","-IRC","--rc-host=localhost:4444");
        Process p = pb.start();

        StreamGobbler errorGobbler = new StreamGobbler(p.getErrorStream(), false);
        StreamGobbler inputGobbler = new StreamGobbler(p.getInputStream(), false);
        errorGobbler.start();
        inputGobbler.start();

        System.out.println("Waiting: \n"+p.waitFor());       
        System.out.println("All done here");
        //p.destroy();
        //System.exit(0);

  } catch (IOException ioe) {
    ioe.printStackTrace();
  } catch (Exception ie) {
    ie.printStackTrace();
  }
}
}

class StreamGobbler extends Thread {
InputStream is;
boolean discard;
StreamGobbler(InputStream is, boolean discard) {
  this.is = is;
  this.discard = discard;
}
public void run() {
 try {
   InputStreamReader isr = new InputStreamReader(is);
   BufferedReader br = new BufferedReader(isr);
   String line=null;
   while ( (line = br.readLine()) != null)
     if(!discard)
       System.out.println(line);    
   }
 catch (IOException ioe) {
   ioe.printStackTrace();  
 }

} }

Here is the Java application using the Apache Commons Net package that I'm trying to connect to the above app running on the same machine:

public class TelnetTest {
public static void main(String args[]) {


    TelnetClient tl = new TelnetClient();
    try {
        tl.connect("localhost", 4444);
        if(tl.isConnected()) {
            System.out.println("Connected successfully!");

            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(tl.getOutputStream()));
            bw.write("quit");
            bw.flush();

        } else {
            System.err.println("Problem with connection");
        }
    } catch(Exception e) {
        System.err.println("Telnet connection threw an exception: "+e.getMessage());
    }
}
}

The latter app works fine if I start VLC using the commands from the first app in the Terminal. Likewise, I can't connect to the first app from the Terminal using "telnet localhost 4444" in the Terminal.

The only difference I can find is in the output from VLC. When running in the terminal:

[0x2786e8] main interface error: no interface module matched "globalhotkeys,none"
[0x2786e8] main interface error: no suitable interface module
[0x201b28] main libvlc error: interface "globalhotkeys,none" initialization failed
Remote control interface initialized. Type `help' for help.

When executing via the top Java application:

[0x4009178] main interface error: no interface module matched "globalhotkeys,none"
[0x4009178] main interface error: no suitable interface module
[0x2017a8] main libvlc error: interface "globalhotkeys,none" initialization failed
[0x4009178] main interface error: no suitable interface module
[0x2017a8] main libvlc error: interface "default" initialization failed

Can anyone help me out here? I'm at a loss. Thank you very much.

You can run VLC as a subprocess and feed it commands through the process output stream. You need to flush the stream and sleep for a little while after each command. The following code doesn't do everything - but it does allow me to play different files in VLC under control of Java.

     String vlcParameters = String.format(
           "-I rc --rc-fake-tty --video-on-top --disable-screensaver --no-video-title-show " +
           "--no-mouse-events --no-keyboard-events --no-fullscreen --no-video-deco " +
           "--x11-display \"%s\" --video-x %d --video-y %d --width %d --height %d",
           ":0.0", // X11 display
           top,      // X
           left,      //Y
           width,    //Width
           height     //Height
           );

     ProcessBuilder pb = new ProcessBuilder("vlc", vlcParameters);

     pb.redirectErrorStream(true);

     vlcProcess = pb.start();

// Later - clear current playlist

        writer.write("clear\n".getBytes());
        writer.flush();
        Thread.sleep(10);

        String playListCommand = String.format(
              "add file://%s\n",
              filePath);

        writer.write(playListCommand.getBytes());
        writer.flush();

        Thread.sleep(milliDuration - 10);

Note - you will need another thread to read the output from VLC so it doesn't block:

     Thread inputThread = new Thread(new Runnable()
        {

        @Override
        public void run()
           {
           InputStream in = vlcProcess.getInputStream();

           BufferedReader bufin = new BufferedReader(new InputStreamReader(in));

           try
              {
              while (true)
                 {
                 String line = bufin.readLine();

                 if (line == null)
                    {
                    System.out.writeln("End of data from VLC");
                    }

                 System.out.writeln("VLC OUTPUT:" + line);
                 }
              }
           catch (IOException ex)
              {
              //...
              }
           }
        },
        "VLC stdout reader");

     inputThread.start();

Found the solution on another forum: http://forums.sun.com/thread.jspa?threadID=5145675

You have to pass the "--rc-fake-tty" argument to VLC when running under Linux or Mac apparently.

Since vlc opens a new DOS window in rc mode, during writer.flush() the code complains that the pipe was closed. this was also verified as the inputThread prints "VLC OUTPUT:nullEnd of data from VLC". Is there a way to avoid it, to link to the newly opened vlc rc window?

Regards

Shahid