Starting a third-part app consumes 50% CPU!

[David Irwin]

All,

I have a third-party application (VLC video decoder from http://www.videolan.org) that I start using Java, specifically using the following Java code:

  // get the runtime object
  Runtime rt = Runtime.getRuntime();
 
  // some other initialization
 
  String commandLine = "C:\Program Files\VideoLan\VLC\vlc.exe";
  this.vlcProcess = rt.exec(commandLine);

I hold onto the process object so that I can close VLC later on.

When I start VLC using my Java application as shown above, the VLC application consumes 50% of the CPU before even doing anything; it's not even decoding video yet! (note: VLC the application is consuming 50% of the CPU, not my Java application; this per the Windows task manager). If I start VLC just by itself it doesn't consume anything more than 1% of the CPU.

Any reason why this would be so? It's causing a real problem when I actually start decoding video because VLC then consumes nearly 100% of the CPU.

Thanks,
Dave

Java 1.5+ on Windows XP
[ June 25, 2008: Message edited by: David Irwin ]

[David Irwin]

Doing a little more research I came across the ProcessBuilder class in the Java 1.5 API. When I start VLC using the process builder the CPU usage is near 1% when idle. I'm hoping that this will help solve my problem.

Dave

[David Irwin]

After looking at the Java 1.5 source it turns out that the Runtime.exec() method actually uses the ProcessBuilder class. And I have been unable to get my application to start successfully using the ProcessBuilder class alone.
Since Runtime.exec() actually uses ProcessBuilder internally I don't expect any fix if I were to get the standalone ProcessBuilder approach to work.

Any ideas?

Thanks,
Dave

[Campbell Ritchie]

You are familiar with the traps in Runtime.exed(), as described in the classic article by Daconta? Please do a search of JavaRanch; there are other threads active at present addressing similar questions.
[ June 27, 2008: Message edited by: Campbell Ritchie ]

[David Irwin]

Originally posted by Campbell Ritchie:
You are familiar with the traps in Runtime.exed(), as described in the classic article by Daconta? Please do a search of JavaRanch; there are other threads active at present addressing similar questions.

[ June 27, 2008: Message edited by: Campbell Ritchie ]

Thanks for the reference...I hadn't read the article but for my sake I unfortunately was already doing much of what was suggested in the article.

Does anyone know of an alternative to using Runtime.exec(), such as some third-party library?

Thanks,
Dave